ELK Asia Pacific Journals – Special IssueProc. Of the Int. Conf: ARIMPIE-2015 Message from the Chairman I am extremely delighted to note that Department of Mechanical Engineering , I.T.S Engineering College, Greater Noida is set to organize the First International Conference on Advancements and Recent Innovations in Mechanical, Production and Industrial Engineering (ARIMPIE-2015) in association with the Indian Society for Technical Education, New Delhi during April 1011,2015. It is my conviction that this conference will provide quick snapshot of major developments and innovations in the subject area with special emphasis on technological breakthrough, competing technologies on the horizon and some key innovations. It will also expose students to the latest developments in the area of expertise and help them correlate with the knowledge garnered during class room teaching. I am sure this conference will provide an opportunity to the academicians, industrialists, scientists and research scholars to present their view and exchange ideas on the above mentioned subjects. Finally, I would like to congratulate all the members of the organizing team for their persistent efforts and commitments to make this event a grand one. Dr.R.P.Chaddha Chairman I.T.S Education Group ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Message from Organizing Chair It is privilege and pleasure to welcome the conference speakers, presenters, delegates and participants to the First International Conference on Advancements and Recent Innovations in Mechanical. Production and Industrial Engineering ARIMPIE-2015. We would like to express our personal gratitude to the sponsors and well wishers for their continued support as well as to our students, faculty and staff who have worked with dedication for ensuring the success of the Conference. In the present day business environment technological edge and superiority is the major growth engine for business. Academic institute provide the fertile ground for innovation and technological breakthrough. Organizing conferences help in diffusion of knowledge and exchange of ideas with the peer group. We are fortunate to have received the support of the I.T.S Management, academic fraternity, industry associates and sponsors. We thank one and all for the support and hope that we will derive benefit from the deliberations in the conference. We wish you all success in accomplishing the goals of the Conference. Dr.Sanjay Yadav Organizing Chair ARIMPIE2015 Dr.Vikas Dhawan Organizing Chair ARIMPIE2015 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Message from Organizing Secretary We are indeed privileged and delighted to host ARIMPIE-2015, the First International Conference on Advancements and Recent Innovations in Mechanical, Production and Industrial Engineering. This conference is aimed to provide a common platform for the interaction of the academia and industry including personnel from research and development organizations. The organizing committee, under the valuable guidance of our Director Dr.Vineet Kansal, has been very active to ensure the successful organization of the conference. Special gratitude and appreciation is due to the various track chairs as they are primarily responsible for the content and conduct of the technical program. The Registrar, Dean Academics and faculty of I.T.S Engineering College deserves special thanks for providing administrative and technical support to ARIMPIE-2015. We wish to express a debt of gratitude to all the program committee members and the outside reviewers. Thanks also to all those who submitted papers to the Conference. We heartily welcome all delegates, invitees, guests and participants to this conference. Dr. Sanjay Mishra Organizing Secretary Mr. Manvendra Yadav Organizing Secretary ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Preface Welcome to the First International Conference on Mechanical, Production and Industrial Engineering ARIMPIE-2015. In order to improve the quality of living, implication of innovative solutions and best practices in Mechanical, Industrial and Production Engineering have critical role. In the near future Mechanical Engineering will be at the forefront in developing new technologies. The prime goal of the conference is to promote research and developmental activities in Mechanical, Production and Industrial Engineering. The conference aimed to provide a common platform for professionals, academicians, researchers and industrialists to share their knowledge and ideas for achieving focused development and advancements in emerging field of these areas. It will help the participants to redefine their horizons in recent innovation in these fields through technical paper presentations and panel discussions leading to networking of participant organizations for effective collaboration in R & D and recognizing the areas which require future research. The organizing committee believes that the conference will assist the participants to connect with the pace of innovation in the Mechanical, Production and Industrial Engineering. This Proceeding is a compilation of quality papers accepted for presentation in the conference. The organizing committee of ARIMPIE-2015 extends their thanks to the authors for accepting to share their knowledge in these Proceedings. All the experts who peer-reviewed the papers are most thanked for ensuring that quality material was published. The guidance given by the members of the International Advisory Committee is greatly acknowledged. The organizations associated with us are most sincerely thanked for making it possible for the Conference and its Proceedings to be realized. Our special thanks to the Director of the college Dr. Vineet Kansal, for providing an environment that was conducive for the smooth accomplishment of the editorial work. I ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 ORGANIZING COMMITTEE Chief Patron International Advisory Committee Dr. R. P. Chadha (Chairman, I.T.S- The Education Group) Prof. Raj Kumar Roy, Cranfield University, UK Patrons Dr.Rajesh Piplani, Nanyang University, Singapore Prof. Mohammed Arif, University of Salford, UK Mr. Sohil Chadha Technological Prof. Nikhil Ranjan Dhar, Bangladesh University of Engineering and Technology, Dhaka (Vice Chairman, I.T.S- The Education Group) Mr. Arpit Chadha Dr. Nandita Hettiarachchi, Ruhuna University, Srilanka (Vice Chairman, I.T.S -The Education Group) Mr. B. K. Arora Prof. R.K. Khandal, Vice Chancellor, Uttar Pradesh Technical University, India (Secretary, I.T.S -The Education Group) Prof. R.L.Sharma, Vice Chancellor, Himachal Pradesh Technical University, India Dr Vineet Kansal (Director, I.T.S Engineering College, Greater Prof. R.S. Agarwal, Senior Advisor & Expert, Ozone Cell, India Noida) Dr.Sanjay Yadav, CSIR-National Laboratory, New Delhi, India Organizing Chairs Physical Prof. A.D. Bhatt, MNNIT Allahabad, India Dr. Sanjay Yadav Head, MED Prof. Abid Haleem, Jamia Millia Islamia, New Delhi, India Dr. Vikas Dhawan Professor, MED Prof. Anuj Jain, MNNIT Allahabad, India Prof. Ashitava Ghosal, IISc Banalore, India Organizing Secretaries Prof. B. Sahay, IIT Patna,India Dr.Sanjay Mishra Associate Professor, MED Prof. H.K.Raval, SVNIT Surat, India Prof. Mohd. Islam, Jamia Millia Islamia, New Delhi, India Mr. Manvendra Yadav Assistant Professor, MED Prof. M.D.Singh, MNNIT Allahabad, India Joint Secretaries Prof. Mohd. Muzaffarul Hasan, Jamia Millia Islamia, New Delhi, India Dr.B.P.Sharma Associate Professor, MED Prof. Puneet Tandon, IITDM Jabalpur, India Prof. R.A.Khan, Jamia Millia Islamia, New Delhi, India Mr. Md. Kamal Asif Khan Assistant Professor, MED Prof. R.S. Jadoun, G. B. Pant University of Agriculture & Technology Pantnagar, India Prof. Ravi Kumar, IIT Roorkee, India II ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Prof. S.K. Garg, Delhi Technological University, India Prof. Sanjay, NIT Jamsedhpur, India Prof. Sanjay Sharma, NITIE Mumbai, India Prof. Sehijpal Ludhiana, India Singh Khangura,GNDDC Prof. Sudhir Kumar, NIT Kurukshetra, India Prof. Uday Shanker Dixit, IIT Guwhati, India Prof. V.K. Jain, IIT Kanpur, India Prof. Vinod Yadava, MNNIT Allahabad, India Dr.Inderdeep Singh,IIT Roorkee, India Dr.Narayan Agarwal,Delhi Institute of Tool Engineering, New Delhi, India Dr. P.M. Pathak, IIT Roorkee, India Dr. Pulok M.Pandey, IIT Delhi, India Dr. Vijay Pandey, BIT Mesra, Ranchi, India Dr. Alok Kumar Das, ISM Dhanbad, India Dr. Atul Thakur, IIT Patna, India Dr. Akhilesh Barve, IIT Bhubaneswar, India Dr. Rakesh Sehgal, NIT Hamirpur, India Dr. Siddhartha, NIT Hamirpur, India Dr. Varun, NIT Hamirpur, India Mr. Arvind Sinha, SAS Motors, India Mr. Deepak Maini, Cadgroup, Australia Mr. R. K .Malhotra, SMC Pneumatics (India) Pvt. Ltd, India Mr. Raj Kumar Soni, Raj Soni & Co., India Mr. Shraman Goswami, Honeywell Technology, India III ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 1. Preface 2. Organizing Committee I II TABLE OF CONTENTS MECHANICAL Vol. 1 S. No. Paper Title and Author(s) 1 Shape Oscillations of a Particle Coated Bubble During Rise in a Liquid Column Prithvi R. Y., SabitaSarkar Tensile Behaviour of 3-Ply Laminate Composite of Sheet Metals Vijay Gautam, Bijender Prasad Stress Analysis of Pelton Bucket using Mechanical APDL Sonendra,NamanAgarwal, T.S.Deshmuk Ships Steering Autopilot Design by Nomoto Model Pradeep Mishra, S K Panigrah ,Swarup Das Material Selection in Bearing Industry Using Multi Criteria based TOPSIS Methodology J. S. Karajagikar, R. R. Manekar Data Acquisition and Monitoring of EMG (Electromyogram) Signals MrinalJyotiSarma, RichaPandey Sustainable Application of Compound Parabolic Solar Concentrator D.K.Patel,P.K. Brahmbhatt Effect of Radiative Heat Transfer Term in Weak Non–Linear Waves in Fluid With Internal State Variables Nahid Fatima Investigation to Compare Heat Augmentation from Plane, Dimpled and Perforated Dimple Rectangular Fins using ANSYS Sachin Kumar Gupta, Harishchandra Thakur Dynamic Response of Selected Fruits using Laser Doppler Vibrometer JitendraBhaskar, Anand Kumar, Bishakh Bhattacharya Experimental Study of Comparison of Simple VCRS and VCRS with Phase Change Material(PCM) as Potassium Chloride (KCL) TalivHussain, SahilChadha, Gaurav Singh, Jaggi,Sourabh,Gourav Roy Study of Fatigue Life Calculation of Steel under Various Loading Condition Anil Kumar , AbhishekPandey Experimental Investigation of ThermalPerformance of Liquid Flat Plate Collector by Comparing Single Glass Sheet with the Double Glass Sheet TalivHussain, Wasiur Rahman, Saddamul Haque, Rocky Singh Labana, Md.Sabbir Ali Effect of Phase Change Material (PCM) as Sodium Chloride (Nacl) in VCRS System as Compare to Simple VCRS System. TalivHussain, Sourabh, NeerajKatoch, SahilChadha, Rahul Wandra 2 3 4 5 6 7 8 9 10 11 12 13 14 IV Page No. 1 7 13 19 25 32 37 45 50 59 63 67 71 76 ELK Asia Pacific Journals – Special Issue 15 16 17 18 19 Proc. Of the Int. Conf: ARIMPIE-2015 Experimental Analysis of A Waste-Heat-Utilization-Strategy using Thermoelectric Device in C.I. Engine R. Srivastava, S.K. Dhiman, J.V. Tirkey Effect of Various Cut-Out on Buckling Analysis of Laminated Composite Plate using FE Simulation Rekha Shakya, Tushar Sharma, Rajendra Bahadur To Evaluate the Performance of VCRS System by Comparing Lesser Superheated Refrigerant(R-134a) to Higher Superheated Refrigerant (R143a) Rahul Wandra, TalivHussain, JagannathVerma, Arjun Sharma,Gourav Roy Kinematic Design Optimization of Planer-Link Mechanism Based Manipulator Jagdish M Prajapati In-Plane Free Vibrations of Symmetrically Laminated Rectangular Composite Plates Kumar Pankaj ,UjjwalBhardwaj,Priyanka Singh 80 85 91 96 101 20 Experimental Investigation of Comparison of Air Cooled and Water Cooled Condenser Attached with Cooling Tower Gourav Roy, TalivHussain, Rahul Wandra 117 21 Computational Fluid Flow Analysis of High Speed Cryogenic Turbine using CFX SushantUpadhyay, ShreyaSrivastava, SiddharthSagar, Surabhi Singh, Hitesh Dimri Thermal Analysis of Various Perforated Tree Shaped Fin Array using ANSYS Sachin Kumar Gupta, Rahul Singh, DivyankDubey, Harishchandra Thakur A Review on the Analytical Analysis and Modeling of Earth Air Tunnel Heat Exchanger JagjitKaur, HarminderKaur Ecoflush - Wastewater Recycling and Rainwater Harvesting Toilet Flush System Mukesh Roy, AyushGoyal, Vivek Kumar Experimental Investigation of Enhancing the COP of VCRS System by using Cooling Tower Gourav Roy,TalivHussain, Rahul Wandra Improvement in Thermal Efficiency of a Compression Ignition Engine using A Waste Heat Recovery Technique Aashish Sharma, Ajay Chauhan, HimanshuNautiyal,Pushpendra Kumar Sharma, Varun Motion Control System of Dc Motor Drive Through PID Control Pragya Singh, HemantChouhan Effect of Subcooling in VCRS as Compared to Simple VCRS System TalivHussain, Arjun Sharma ,Navin, Rahul Wandra, Gaurav Roy Comparison of Different Failure Theories of Composite Material: A Review SupriyaKabra, N.D. Mittal Use of Polymer Matrix Composites for Conventional Steel Drive Shafts: A Study Yusuf Abdulfatah Abdu Experimental Investigation of Comparison of VCRS with Phase Change Material as Sodium Sulphate (Na2SO4) and Simple VCRS System. Rahul Wandra, Taliv Hussain, Gaurav Singh Jaggi, Sourabh,Gourav Roy 122 Behaviour of Polymer Matrix Composite under Different Environmental Conditions Pathak, ShubendraNathShukla,VikasChaudhary, Kaushalendra Kr Dubey Study of Flow Field of River for Hydro Kinetic Turbine Installation A. Mishra, A.Kumar, M. Singhal, 191 22 23 24 25 26 27 28 29 30 31 32 33 V 129 137 143 147 152 161 167 174 179 187 195 ELK Asia Pacific Journals – Special Issue 34 35 36 Proc. Of the Int. Conf: ARIMPIE-2015 A Review on the Performance of the Nano Fluid Based Solar Collectors - Solar Energy Kapil Sharma, Satnam Singh, ManvendraYadav, Sanjay Yadav, Naveen Mani Tripathi Study of Hardness & Microstructure of AISI 1050 Medium Carbon Steel after Heat Treatment Processes Sanjeev Kumar Jaiswal, Rajesh M, .T.Sharma, Vineet Kumar Condition based Predictive Maintenance on board Naval Ships S Jaison, KarajagikarJayant PRODUCTION & INDUSTRIAL Paper Title and Author(s) 37 Soft Computing Technique for Product Design Suggestion in Smart Manufacturing Industry Jitesh Kumar Khatri, Jyoti Kumar Experimental Investigation of Electrical Discharge Face Grinding of Metal Matrix Composite (Al/Sic) Ram Singar Yadav, Gyan Singh, Vinod Yadava Heuristic for Enabling Lean Characteristics in Cellular Manufacturing using Reconfigurable Machines Rajeev Kant, L N Pattanaik, Vijay Pandey Finite Element Analysis of Laser Beam Percussion Drilling of TBC Superalloys Km Afsana, VinodYadava Dynamic Modelling and Machining Stability in A New Mill-Spindle Design for Drilling Machine JakeerHussain, Srinivas J An Experimental Investigation of Travelling Wire Electrochemical Spark Machining (TW-ECSM) of Epoxy Glass Using One-Parameter-At-A-Time (OPAT) Vevek Kumar, VinodYadava Experimental Study of Electrical Discharge Machining on Stainless Steel Workpiece using One Parameter at A Time Approach Param Singh,VinodYadava, Audhesh Narayan Dry Sliding Wear Behaviour of Mg/Tip (Mg)-Based Composite Obtained Through P/M Route SanketPatro, M.Appoothiadigal, B.K.Raghunath Effect of Magnetic Field on Electrode Wear Ratio in Electro-Discharge Machining Govindaraju Anand, Komaraiah, S.Satyanarayana, Manzoor Hussain A Quantitative Analysis of Modular Manufacturing in Garment Industry by using Simulation B.Sudarshan, D. NageswaraRao Emerging Modelingand Simulation Techniques for Friction Stir Welding- A Review PrashantPrakash, Shree PrakashLal, Sanjay Kumar Jha Preparation and Mechanical Properties of Sintered Zrb2-Graphite Composites by Spark Plasma Sintering (SPS) Method NiteshKuma, Binay Kumar,Lokesh.C. Pathak ANN Modelingand Multi Objective Optimization of Electrical Discharge Machining Process SanjeevKumarSinghYadav, DeepakAzad 39 40 41 42 43 44 45 46 47 48 49 213 220 Vol. 2 S. No. 38 201 VI Page No. 228 233 240 245 252 258 264 270 276 281 288 296 300 ELK Asia Pacific Journals – Special Issue 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 Proc. Of the Int. Conf: ARIMPIE-2015 Optimization of Aluminium Die Casting Process using Artificial Neural Network SanatanRatna, SwetNisha A Review on Sisal, Jute and Bamboo Based Natural Fibers Amrinder Singh Pannu, Sehijpal Singh, VikasDhawan Multiobjective Optimization for Wire EDM of WC-Co Composite using GRA with Entropy Measurement Sachin Dev Barman, Ajay Suryavanshi Optimization Of Electro Discharge Machining of Superalloys and Composites: A Review AmritShiwani, Amit Sharma A Investigation of Machinability of Inconel 718 In EDM using Different Cryogenic Treated Tools: A Review Pradeep Joshi, Shiv DayalDhakad Present &Future of Automation in Automotive Industries. HemangSolanki, K.V.Parmar Friction Stir Welding of AluminumAlloys 6xxx Naveen Gadde, ShikharGoel, PiyushGulati Development and Characterization of Green Composites: A Review Jai InderPratap Singh, VikasDhawan, Sehijpal Singh Study of Mechanical Properties of Rice Husk Composites V K Joshi, V. Upreti, A., Chaudhary An Overview of Turning Process Monika Saini,Ravindra Nath Yadav, Sunil Kumar Research and Developments in Laser Beam Machining – A Review Bhaskar Chandra Kandpal, Nilesh Ramdas, Rakesh Chaurasia, Abhishek singh, Vishal Rawat, Saatvik Singh Effect of Transverse Weld Feed Rate on Microstructure and Tensile Properties of FSW Weld of AA6061 Ashwani Kumar, R S Jadoun Modelling and Simulation of Temperature Distribution in Laser Cutting of Ti-Alloy Sheet ShivaniPandey, Arun Kumar Pandey To Study the Effect of Various Parameters on Finishing of Inner Surfaces of Brass Tubes using Magnetic Abrasive by RSM Jai InderPratap Singh, VikasDhawan, Sehijpal Singh Simulation of Hole-Taper And Material Removal Rate Due to Single Pulse Laser Beam Drilling Sanjay Mishra, VinodYadava Analysis of Process Parameters of CNC Lathe Turner by Response Surface Methodology RichaSaxena, AbhishekPandey Modelling of Electro-Discharge Machining of Difficult-to-Machine Materials: An Overview Achal Gupta,AdityaAgrawal, Amit Sharma VII 310 315 321 331 340 349 356 366 374 377 387 393 399 405 416 422 429 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 INDUSTRIAL S.No. 67 68 69 70 71 72 73 74 75 76 77 Vol. 2 Paper Title and Author(s) Name Urban flooding and its risk associated with governance and management strategies: a case study of Anand District, Western India Pankaj Kumar, Srikantha, Herath, Ram Avtar, Kazuhiko Takeuchi Ant colony optimization for scheduling of PCBs using single machine Akshaye Malhotra, Vijay Pandey, S.K. Sahana, Somak Datta Assessing the Success of Six Sigma: An Empirical Study S. K. Tiwari, R. K. Singh, S. C. Srivastava Product Development by Using Modular Design Structure Matrix Puneet Saini, Ayush Dubey, Vijay Pandey Design of a simple Vending Machine using Radio Frequency Identification (RF-id) Sunil Kumar, Richa Pandey Imperatives of Green Manufacturing Abhishek Kumar Singh, Sanjay Kumar Jha, Anand Prakash Understanding Quality In Home Based Brassware Manufacturing Units in India Kapil Deo Prasad, Sanjay Kumar Jha, Ritesh Kumar Singh Application of Lean Manufacturing to Improve the Electronics Industry in Egypt: a Case Study Ali Abd El-Aty , Ahmad Farooq , Azza Barakat , Mohamed Etman Solving Multi-Objective Problem on Supply Chain Performance Measure by multiObjective Evolutionary Algorithm Susmita Bandyopadhyay, Indraneel Mandal Multi-objective Goal Programming and its Applications: A review Jyoti, Himani Mannan Modeling the Individual/Group Knowledge Sharing Barriers: An Approach of Similarity Coefficient B P Sharma, Harsh Gupta VIII Page No. 438 441 448 462 468 472 479 484 490 496 502 ELK Asia Pacific Journals – Special Issue 1. SHAPE OSCILLATIONS OF A PARTICLE COATED BUBBLE DURING RISE IN A LIQUID COLUMN Prithvi R.Y Department of Metallurgical and Materials Engineering Indian Institute of Technology Madras Chennai, India Sabita Sarkar Department of Metallurgical and Materials Engineering Indian Institute of Technology Madras Chennai, India
[email protected] Abstract— Particle coated bubble and its stability plays a major role during particle recovery in flotation process. A rising bubble undergoes shape oscillations which are subjected to change when particles are coated on the surface of a bubble. Experiments were performed to understand the effect of particle coating on a rising bubble in a liquid column. Hydrophobic Low density polyethylene particles were used to coat the bubble surface and water was used as liquid medium. Two images (one direct and mirror image) were taken for all position during rise of the bubble. Effect of different fraction of particle coating on the bubble surface oscillations was studied. It is observed that the shape oscillations of bubbles are arrested as coating fraction increased from 10% to 50% with the latter undergoing almost no deformation in shape. The bubble in this case behaves like a rigid body and exhibits pure rotation as it moves up. Keywords—shape oscillations; particle coated bubble; single bubble rise ; coating fraction. Proc. Of the Int. Conf: ARIMPIE-2015 I. INTRODUCTION Bubble flotation in presence of particles is a phenomena which has wide spread application like waste water treatment, petrochemical plants, froth flotation process, paper industry and in refining operations like secondary steel making process. Understanding the behaviour of bubble motion and its characteristics in presence of particles is a key step in evaluating preliminary variables like air flow rate, bubble size, particle size etc. with respect to its application in each field. A significant amount of research has been carried out in understanding the behaviour of a single bare bubble rising in a fluid column [2,6]. The theory behind shape oscillations of a single rising bubble has been given in detail by several researchers [1,3 & 5]. However motion of particle coated bubble in liquid medium is not so evident in literature. In this work, motion of particle coated single bubble was studied experimentally. The effect of particle coating on the bubble surface oscillation and the overall bubbly motion was main focus of this study. Strongly hydrophobic polymeric Low Density Polyethylene (LDPE) particles were chosen with interest to alumina inclusions present in molten steel [4]. The shapes of bubbles were chosen in the ellipsoidal regime which is commonly used for removal of alumina inclusion in tundish [7]. EXPERIMENTAL METHODOLOGY In order to study the shape oscillations of single bubble during rise with particles coated on the bubble surface, a bubble column made of plexiglass was fabricated. A schematic representation of the experimental set-up is shown in Figure 1. The tank comprised of two compartments located one below the other. Initially the tank was filled with distilled water up to a height of 0.55 m in the presence of polymeric LDPE particles inside the lower compartment. The particles which have specific gravity of 0.92 were prevented from floating to the upper compartment by providing a slide door whose opening was controlled manually. An air bubble was held at the tip of a nozzle using an infusion pump and the particle-water mixture was stirred inside the compartment with the help of an impeller arrangement powered by a universal motor. The speed of rotation of the impeller and II. 1 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 duration of rotation controlled the coating fraction of particles on the bubble surface. In this study the size of LDPE particles chosen were from 150-210 microns and the bubble sizes were 6.8 and 4.2 mm. After allowing sufficient time for the particle-water mixture to reach a quiescent state the slide door was opened and the air pump was operated again. The particle laden bubble was detached from the nozzle and moved upwards due to buoyancy. A test section between the heights 0.019 m to 0.028 m in the upper portion of the tank was illuminated with white coloured diffuse back lighting. This was the region where the particle coated bubble behaviour was studied. A mirror was placed inside the tank at an angle of 45 to the camera axis. Light was projected on to the mirror using a screen as a reflector and this method provided back lighting for front view where the bubble appeared white with dark background and the side (reflected) lighting illuminated the mirror image. In this way both the front and side views of the bubble could be obtained using a single camera placed in front of the experimental setup. Figure 1. Schematic of the Experimental Set-up III. The bubble rise and shape oscillations was captured using a CMOS camera (Teledyne Dalsa) having a frame rate of 300 frames per second and a resolution of 640 × 480 pixels. The images recorded were originally in greyscale format. The greyscale images were then converted to binary format in subsequent steps by the method of intensity thresholding, using Matlab14 software. At these stage properties like major axes, minor axes, centroid, and bubble boundary were measured using Matlab 14 - image processing toolbox. In order to determine the particle coating fraction on the bubble, the area of particle coverage was determined by fitting a closed spline around the periphery of the region covered with particles using Image J-image processing software. RESULTS AND DISCUSSION A. Behaviour of Particle coated Bubble Bubbles with different extent of particle coating and at different times were observed during the experiments. In case of the bubble with 10% particle coating at the surface, oscillations were altered and reduced drastically from the case of that of bare bubble. The oscillations were accompanied by rotation of the bubble as it moved upwards. The region where the interface was coated with particles showed no surface oscillation and behaved like solid surface. The surface oscillations were prevalent only at the regions where there were no particles. This altered the overall oscillating behaviour of the bubble. When the extent of coating on the bubble surface increased to almost half of the bubble surface area, the oscillations were completely arrested. The polymer particles completely retarded the surface deformation and the bubble did not undergo any shape oscillation during rise. Instead the bubble exhibited only rotation about its minor axis. The flow past the bubble at the 2 ELK Asia Pacific Journals – Special Issue boundary experienced no slip at regions where the surface retardation had occurred. Visual images of a bubble of 6.8 mm diameter with different particle coatings and at different times are compared and shown in Figure 2. The particle coating on the bubble increases drag force that it experiences and reduces the rise velocity. Experiments were done with a bubble having diameter of 4.2 mm (Figure 3) and a similar behaviour was observed. The only difference was that the amplitude of oscillations undergone by the 4.2mm bubble was comparatively lesser than that of the 6.8mm bubble. The rise velocity in this case is more when compared to that of 6.8mm diameter bubble, as coating fraction is more and the bubble area is lesser. The force due to buoyancy for the 4.2mm bubble exceeds the drag force. B. Effect of particle coating on shape oscillations The shape oscillations of bubbles are generally expressed in terms of spherical harmonics with 2,0 and 2,2 as the dominant modes [3]. These two modes are the dominant modes of shape oscillation for an ellipsoidal bubble. Mode 2,2 shape oscillations of the bubble are axisymmetric in nature. In this mode, t=1s t=1s Proc. Of the Int. Conf: ARIMPIE-2015 the capillary wave is assumed to travel around the equator of the bubble and is characterized by the ratio of major axes obtained from the direct image (dd) to the major axis of that from the mirror image (dm), R=dd/dm. The interpretation of this mode of oscillation is that the bubble is an ellipsoid rotating about its minor axis as it travels vertically upwards and as it does a 2-D projection of the 3-D bubble in either the front or side plane will constitute major axes of different lengths. Thus the ratio of major axes R interprets change in the major axes length due to rotation about its minor axes. Figure 4 shows mode 2,2 oscillations for bare bubble and 10% particle coated bubble. The 6.8 mm bubble shows a distinctive difference in oscillation between the bare bubble and a particle coated bubble, whose values of R are varying from 0.5 to 1.5 for a bare bubble and limited from 0.8 to 1.2 for the particle coated bubble. This is an indication that the particle coating has a decreasing effect on the extent of elongation of the major axes. However for the 4.2 mm bubble size, particle coating seems to have resulted in increased length of one of the major axis (one seen from the direct image) as the value of R remains always greater than unity. t=1s t = 1.012 s t = 1.012 s t = 1.012 s t = 1.024 s t = 1.024 s t = 1.024 s 3 ELK Asia Pacific Journals – Special Issue t = 1.036 s Proc. Of the Int. Conf: ARIMPIE-2015 t = 1.036 s t = 1.036 s Figure 2. Images of a 6.8 mm bubble for a time up to 0.036 s A) bare bubble undergoing shape deformation B) 10% coated bubble undergoing partial deformation C) 50 % coated bubble with no deformation t=1s t=1s t=1s t = 1.012 s t = 1.012 s t = 1.012 s t = 1.024 s t = 1.024 s t = 1.024 s t = 1.036 s A t = 1.036 s B t = 1.036 s C Figure 3. Images of a 4.2 mm bubble for time up to 0.036 s A) bare bubble undergoing shape deformation B) 10% coated bubble undergoing partial deformation C) 50 % coated bubble with no deformation 4 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 B A Figure 4. Plot of R vs time for bare bubble and 10 % particle coated bubble. A) 4.2 mm bubble B) 6.8 mm bubble Deq Deq Time (s) Time (s) A B Figure 5. Plot of Deq vs time for bare bubble and 10 % particle coated bubble. A) 4.2 mm bubble B) 6. 8 mm bubble Mode 2,0 shape oscillation is represented by equivalent major axis defined as deq = √(dd × dm). This is an interpretation of the bubble fluctuating from oblate spheroid to prolate shape. In reality it does not transform completely to prolate shape but as it tends to oscillate in the 2,0 mode with alternating elongation and contraction of the major axes. This mode of oscillation is non-axisymmetric in nature and the capillary waves are assumed to be moving around the bubble from one end of the bubble pole to another. Thus it is elongation in major axis length gets reduced since the particles inhibit wave action at the bubble surface and behave as a rigid body. For the 4.2mm bubble size the arrest in major characterized by obtaining an equivalent diameter of a circle whose surface area is the same as that of the ellipse in the cross-section plane containing the two major axes (Deq). It can be seen from Figure 5 that in the case of a bare bubble as well as partially coated bubble the amplitude of 2, 0 mode of oscillation is greater for the size corresponding to 6.8mm bubble size since it naturally has greater major axes lengths. For this bubble size when particles are coated the axes shrinkage is seen more predominantly as there is a drastic decrease in amplitude of Deq of particle coated bubble. The complete 5 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 prevention of surface deformation when almost half of the bubble surface area was coated can be evidently seen in the images in Figure 2C and Figure 3C and it is inappropriate to use surface harmonics to describe such a body which does not undergo shape oscillation. As the bubble surface deformation is completely arrested the restoring capillary force is retarded preventing any further shape oscillation. Bubbles,” Applied Scientific Research, vol.58, pp.387-408, 1998 IV. CONCLUSIONS LDPE particles do not detach from the bubbles for both sizes of 4.2mm and 6.8mm due to shape oscillations during rise in the static liquid column. When the coating fraction on the bubbles is as mild as 10 %, the bubble surface deformation occurs only at regions, where particles are absent. Thus overall oscillation in amplitude is reduced The reduction in elongation of major axes is more for a particle coated smaller ellipsoidal (4.2mm size) than the larger ellipsoidal bubbles (6.8 mm size). Heavily coated bubbles with coating fraction as high as 50%, shows no deformation behaviour, instead they behaves like a rigid body undergoing pure rotation during rise. V. [4] J.P. Rogler, “Modeling of inclusion removal in a tundish by gas bubbling , ” M.S. Thesis, Ryerson University, 2001. [5] C. Veldhuis, A. Biesheuvel , L. van Wijngaarden, “Shape oscillations on bubbles rising in clean and in tap water,” Physics Of Fluids, vol.20, pp. 1-12, 2008. [6] A.W.G de Vries, A. Biesheuvel, L. van Wijngaarden, “Notes on the path and wake of a gas bubble rising in pure water,” International Journal of Multiphase Flow, vol.28(11), pp.1823-1835, 2002. [7] L.Zhang, S.Taniguchi, “Fundamentals of inclusion removal from liquid steel by bubble Flotation,” International Materials Reviews, vol. 45(2), pp.59-82, 2000. REFERENCES [1] C. Brucker, “Structure and Dynamics of the wake of the bubbles and its relevance for bubble interaction,” Physics of fluids, vol. 11(7), pp. 17811796, 1999. [2] P.C. Duineveld, “ The rise velocity and shape of bubbles in pure water at high Reynolds number,” J.Fluid Mech, vol 292, pp. 325-332, 1995. [3] K. Lunde, R.J. Perkins, “Shape Oscillations of Rising 6 ELK Asia Pacific Journals – Special Issue 2. TENSILE BEHAVIOUR OF 3-PLY LAMINATE COMPOSITE OF SHEET METALS Vijay Gautam1, Assistant Professor, Department of Mechanical Engineering, Delhi Technological University, Delhi-110042. Email:
[email protected] Bijender Prasad2, Research scholar, Department of Mechanical Engineering, Delhi Technological University, Delhi-110042. Email:
[email protected] Abstract- Recently, clad metallic materials, consisting of two or more layers, have been preferred in various industrial applications because of their unique corrosion resistance, specific strength, and surface properties. The present study has been carried out on three ply composite laminate, containing AISI304L austenitic stainless steel on one side and AISI430 on the other side with AA1050 in the core of the blank. Apart from excellent corrosion and mechanical properties of stainless steel three ply composite laminate possesses exceptional thermal and electrical conductivities, which makes it useful for utensils formed by deep drawing process. Circular blanks of composite laminate, produced by cold roll bonding, with a combined thickness of 2.5mm, were procured in the annealed condition from a leading manufacturer. To ensure the bond strength of 3ply AISI304/AA1050/AISI430 sheets, peel tests on various specimens were performed according to ASTM-D1876-08 standard. Tensile samples as per ASTM E8M standard, were laser cut in three different directions i.e. parallel, inclined at 45° and transverse with respect to rolling direction. Tensile specimens were tested to study the deformational behaviour in uniaxial tension, on a 50kN UTM. Keywords- Clad metals; Three ply laminate composite; cold roll bonding; peel test; tensile behavior. I. INTRODUCTION With the advancement in technology in forming with sheet metals, new clad materials Proc. Of the Int. Conf: ARIMPIE-2015 have been evolved and designed for various industrial applications such as automobile, aerospace and electrical industries. These laminated sheets consist of different kind of sheet metals with different mechanical, physical properties and specifications to suit the various applications. Various parameters such as material type, thickness ratio, arrangement and multiplicity of the metals, surface preparation, bonding parameters and post heat treatment results in unique deformational behavior [1-5]. Although, Clad sheets have been produced by several solid state bonding methods such as diffusion, explosive and roll bonding but cold roll bonding (CRB) is the most efficient and cost effective [6,7]. Many researchers have contributed significantly on the various issues related to formability of roll bonded clad sheets. In the recent development of the clad sheets, most widely used material combinations are Al with Cu, Al-Fe, Al with stainless steel, Zn- Al with stainless steel, Al-Cu with steel, Ti with steel etc. [8,9]. Akramifard et al 2014 carried out experimental studies on effect of reduction and subsequent annealing temperatures on mechanical properties and bond strength of three layered AA1050-304L-AA1050 clad sheets, during roll bonding. An important contribution of their work was the correlation of tensile and peel test on the basis of principles of mechanics of materials. The mechanical properties of some laminated composite sheets, mainly of stainless steel/aluminium sandwich sheets, have been the subject of examination for many years. Choi et al. 1997 experimentally investigated the deformation behaviour of Al-STS430 bi-layer clad sheets under uniaxial tension and concluded that a difference in planar and normal anisotropy results in the warping of edges of tensile specimens. The material property of the laminated sheet changes in the thickness direction, their deformation behavior should be affected by the blank placement position during forming by deep drawing, i.e. which side of the sheet would contact punch or die. Because of such interesting formability issues, the behavior of laminated sheets is the subject of much research. However, only a few studies have discussed the combination of 3-ply clad sheets of AISI304/AA1050/AISI430. In view of the 7 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 above the present study deals with the tensile behaviour of 3-ply laminate composite. II. A. METHODOLOGY Selection of material Selection of material is based on the increasing popularity of multi ply clad sheets in deep drawn utensils, owing to the advantages of excellent formability, good surface finish of class of 2B, uniform heating and better heat transfer. Circular blanks of 3-ply clad sheet of AISI304/AA1050/AISI430 material of effective thickness of 0.4, 1.5 and 0.6mm respectively, that are joined by roll bonding and thermal treatment, due to a metallurgical bond under high pressure, was procured from a leading supplier in India. The chemical composition of individual sheets were obtained by spectrometry- analysis and are given in Table 1. B. The peeling test To investigate the bond strength due to CRB, the peeling test was performed according to ASTM-D1876-08 standard (subsized). Specimens for the peel test were laser cut in the sub-size of 160X 25 mm due to limited availability of the material. Since it is difficult to detach the bonded sheets mechanically, one end of the each specimen was immersed in the solution of sodium hydroxide to dissolve aluminium. The remaining length with intact bond was used for the peel test as shown in the Fig. 1. The specimens were prepared in such a way that each bonded sheet of steel i.e. AISI304 and 430 be peeled from aluminium bond respectively. The stainless steel sheet to be peeled was held in the lower fixed jaw and the rest with the upper movable jaw fixed with the cross -head on the 50kN UTM. All the tests were conducted at a cross head speed of 10mm/min. Fig. 1. Peel test arrangement on 50kN UTM C. The tensile test Most common approach to characterize the behaviour of a material is by conducting uniaxial tensile tests. In this work, simple tension tests were carried out on a universal testing machine of maximum capacity 50 kN as shown in Fig. 2. The tensile test specimens as per standard ASTM-E8M, were prepared by laser cutting of the blank as shown in Fig. 4. The anisotropy of the 3-ply clad sheet metal was investigated by performing tensile tests at specimen orientation of 0°, 45° and 90° to the rolling direction (RD) and are shown in Fig. 5. The tests were carried out include monotonic loadings in tension. Each test is performed at least three times to ensure good reproducibility of the experiments. The tests were carried out at a cross head speed of 2.5mm/min. Typical engineering stress strain curve is plotted on the basis of force and displacement data acquired from the dedicated software. D. Determination of tensile properties The strain hardening exponent (n) and the strength co efficient (K) values are calculated from the stress strain data in uniform elongation region of the stress strain curve. 8 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Fig. 3. Tensile tested specimens Fig. 2. 50kN Universal testing machine TABLE I CHEMICAL COMPOSITIONS OF SHEET MATERIALS USED IN THE LAMINATE Steel Sheet material C M Si Al Ni Cr S P n AISI304 0.05 1.450 0.820 0.044 9.620 18.03 0.009 0.023 AISI430 0.12 0.902 0.675 0.038 0.621 17.02 0.023 0.026 AA1050 0.18 0.018 0.156 Rest 0.032 0.012 0.015 0.034 The plot of ln(true stress) versus ln(true strain) which is a straight line is plotted as discussed below : The power law of strain hardening is given as : σ = K Єn (1) where σ and Є are the true stress and the true strain respectively. Taking log on both sides Log (σ ) = log (K) + n log (Є) (2) Fig. 5. Tensile specimens at different orientations w.r.t. RD This is an equation of straight line and the slope of which gives the value of 'n' and 'K' can be calculated taking the inverse natural log of the y intercept of the line as shown in Fig. 8. III. Fig. 4. Laser cutting of tensile specimens RESULTS AND DISCUSSION To determine the bond strength of AA1050 with AISI304 and 430 respectively, the peel test 9 ELK Asia Pacific Journals – Special Issue specimens were prepared and tested on 50kN UTM of Tenius Olsen make. The peeling force and distance data were recorded using a dedicated software Horizon and the plot between them is shown in Fig. 6. The average peel strength was determined as the ratio of peeling force to the peeling width. The range of the peeling strength of AISI 304 from AA 1050 was between 30 to 51N/mm, whereas peeling strength of AISI430 from AA1050 was found to be between 20 to 26N/mm. The experimental investigation showed that the peeling strength of AISI304 is higher than AISI430 by a factor of 1.5 approximately. In both the peeling tests, the peeling strength remained stable for an appreciable length of 80mm with a slight dip in between at 40mm of peeling distance. Fig. 6. Curve between Peeling force and Peeling distance Proc. Of the Int. Conf: ARIMPIE-2015 The peeling strength of aluminium from AISI 304 was 40N/mm on an average basis, whereas the peeling strength of AISI430 was 25N/mm. Peeling strength became maximum as the peeling distance reaches near the end of the specimens. Same trend was observed in all the tests conducted. To investigate the deformational behaviour, tensile tests were performed on the specimens cut at three different orientations i.e. parallel to, inclined at 45° and perpendicular to the RD. The various tensile properties are given in Table 2. In all the tensile tested specimens, nucleation of crack was observed to initiate from 0.6mm thick AISI430 which may be contributed to the lower ductility of this steel grade. Some waviness or warping were seen at the edges of the tested specimens due to the difference in anisotropy of individual sheets. A typical true stress-strain curve is shown in Fig. 7. Tensile specimens oriented at 45° to the RD showed maximum ductility on an average of 57% whereas least ductility was found with the specimens oriented at 0° to the RD. Highest tensile strength of order of 260MPa was observed in the specimens oriented at 90° to the RD and least strength was seen in specimens oriented at 0° to the RD. The strain hardening exponent (n) as shown in Fig. 8, which is an indicator of workability at room temperature was found to be of order of 0.25 on an average basis. High ductility coupled with excellent strain hardening exponent and strength is required in deep drawing of the utensils. TABLE II TENSILE PROPERTIES OF COMPOSITE LAMINATE AT DIFFERENT ORIENTATIONS wrt RD Orientation Yield w.r.t. Rolling (MPa) Direction (RD) Stress Ultimate Tensile strength (MPa) Percentage elongation (%) Strain Hardening Coefficient (n) Strength Coefficient, (K) (MPa) 0° 171 242 44.7 0.234 420 45° 177 254 56.0 0.256 456 90° 178 262 47.2 0.255 470 10 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Fig. 7. True stress vs True strain plot for composite laminate oriented at different directions Fig. 8. ln(True stress) vs ln(True strain) plot for composite laminate IV. CONCLUSIONS On the basis of the experimental investigations conducted to study the deformational behaviour in uniaxial tension test of 3-ply laminate composite of AISI304/AA1050/AISI430, following conclusions can be drawn: 1. The peeling strength of the bond of AISI 304 with AA1050 is of order of 40N/mm which is approximately 1.5 times higher than that of AISI 430 with AA1050. 2. The peeling strength increases towards the end of the peeling distance. 3. Tensile specimens oriented at 45° to the RD showed maximum ductility on an average of 57% whereas least ductility was found with the specimens oriented at 0° to the RD. 4. In all the tensile tested specimens, nucleation of crack was observed to initiate from 0.6mm thick AISI430 which may be contributed due to the lower ductility of this steel. References [1] J.Y. Jin and S.I. Hong , “Effect of heat treatment on tensile deformation characteristics and properties of 11 ELK Asia Pacific Journals – Special Issue [2] [3] [4] [5] [6] [7] [8] [9] Proc. Of the Int. Conf: ARIMPIE-2015 Al3003/STS439 clad composite”. Mater.Sci.Eng., A 2014; 596:1–8. L. Chen , Z. Yang , B. Jha , G. Xia and J.W. Stevenson “Clad metals, roll bonding and their applications for SOFC interconnects”, J Power Sources 2005;152:40–5. E.Y. Kim ,J.H. Cho ,H.W. Kim and S.H. Choi . “Evolution of deformation texture in Al/Al– Mg/Al composite sheets during cold-roll cladding”, Mater.Sci.Eng, A 2011;530:244–52. I.K. Kim and S.I. Hong . “Effect of component layer thickness on the bending behaviors of roll-bonded trilayered Mg/Al/STS clad composites”. Mater.Des. 2013;49:935–44. H.G.Kang , J.K. Kim, M.Y. Huh and O. Engler . “A combined texture and FEM study of strain states during rollcladding of five-ply stainless steel/aluminum composites”. Mater.Sci.Eng, A 2007;452–453:347– 58. I.K. Kim and S.I.Hong. Mater.Des.49(2013)935–944. H.R.Akramifard , H. Mirzadeh and M.H. Parsa,“Estimating interface bonding strength in clad sheets based on tensile test results” , 2014, Mater.Des. H.R.Akramifard , H.Mirzadeh and M.H.Parsa “Cladding of aluminum on AISI 304L stainless steel by cold roll bonding: Mechanism, microstructure, and mechanical properties” Mater.Sci.Eng. A613 (2014)232–239. S.H. Choi ,K.H. Kim, K.H. Oh and D.N. Lee .“Tensile deformation behavior of stainless steel clad aluminium bilayer sheet”, Mater.Sci.Eng. A222 (1997) 158-165. 12 ELK Asia Pacific Journals – Special Issue 3. STRESS ANALYSIS OF PELTON BUCKET USING MECHANICAL APDL Sonendra*1,N. Agarwal*2, T.S.Deshmuk#3 * Mechanical Department, ITS Engineering College, Gr. Noida,Uttar Pradesh (India) # Civil Department. MANIT Bhopal, Madhya Pradesh (India) 1
[email protected] [email protected] 3
[email protected] Abstract----In the present work an attempt has been made to analyse the stress developed on the surface of Pelton bucket using Mechanical APDL. The geometric modeling of this bucket has been done using CATIA software for a 50 m head and stress analysis has been done in Mechanical APDL. The stress analysis has been done considering bucket as a cantilever element fixed to the disc at one end with the force of jet applied at the splitter. The stress analysis has been done for flow rates ranging from 100 lit/sec to 150 lit/sec and speed ranging from 700 rpm to 900 rpm. It is observed that 1st principle stress is higher than 2nd principle stress and 3rd principle stress. Von Mises stress as well as all three principle stresses decreases as rotational speed of pelton wheel increases. Proc. Of the Int. Conf: ARIMPIE-2015 motion.Pelton turbine is tangential flow impulse turbine.APelton turbine consists of a series of buckets mounted around the periphery of a circular disc. II.GEOMETRIC MODELLING The geometric modelling of the given pelton bucket has been done using CATIA software. In the present work, the runner of a Pelton turbine model for 50 m head has been used for stress analysis. The modelling of the runner blade surface was done with the help of profile coordinates at various sections. The coordinates were available for 6 sections(AA, B-B, C-C, D-D, E-E, F-F) along the length of the blade and 5 sections (U-U, W-W, S-S, K-K, R-R) along the width of the blade. In addition to this, the coordinates of the plan view as well as lip surface were also available. Initially the curves for all the 11 sections were plotted (in different planes) with the distances between the adjacent sections being determined on the basis of plan view. Distance between splitter and E-E curve, E-E curve and A-A curve, A-A curve and F-F curve, F-F curve and B-B curve is 4.15 mm. Distance between splitter and C-C curve is 28.07mm. I.INTRODUCTION The Pelton turbine is a hydraulic prime mover which generates power by first converting the pressure energy of water into kinetic energy with the help of jet nozzle assembly and then mechanical power is developed from this kinetic energy with the use of runner. Runner of Pelton turbine is made of buckets which are mounted on the periphery of a disc.The bucket of Pelton turbine has very complex geometry. The kinetic energy of a jet of water is converted into angular rotation of the bucket as the jet strikes. The highvelocity jet of water emerging from a nozzle impinges on the bucket and sets the wheel into Fig.1 Profile of Pelton Bucket 13 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Distance between splitter and DD curve is 37.49 mm.Section U-U passes through origin. Distance between U-U curve and W-W curve is 20.87mm. Distance between UU curve and SS curve is 23 mm. Distance between W-W and KK curve 11.45 mm. Distance between R-R and S-S curve is 11.45 mm. The width of the bucket is 104.5 mm. Using the given co-ordinates, curves were created using point and spline commands. The final assembly of all the bucket curves for 11 sections is shown below III.NUMERICAL SIMULATION numerical simulation of this problem is done using Mechanical APDL. This software is based on the principle of Finite Element Analysis. The basic steps involved in numerical analysis are as follows: Fig.2 Sections of bucket profile B. Processing or Solution phase- In this phase, all the details for solution are specified. The analysis type used for stress calculations is static structure analysis.Load and constraints are considered as boundary conditions. After this using inner curve of all sections (A-A, B-B, C-C, D-D, E-E, F-F, U-U,W-W, S-S, K-K, R-R ),a surface is generated. This surface forms the inner surface of bucket. Similarily using the outer curve of all sections the outer surface of bucket is created. Both surfaces are converted into a solid bath tub type shape. After this the lip area is created. In this way we obtained the profile of half-bucket. Mirror command is used to obtain remaining half profile of bucket. The complete solid model of the bucket is shown below A. Pre- Processing- In the pre-processor the material definition and meshing of the imported solid model was done. The element used in this study is SOLID187. After selecting the element type the material properties(Modulus of Elasticity, Poisson’s Ratio, Tensile Strength, Ultimate)are defined. Meshing is very important part of pre-processing in any FEA software. Mechanical APDL offers two options - area, volume. Area is for 2D geometry and volume is for 3D geometry. In the present work volume was chosen. Free volume meshing is used for this analysis. Meshing done by this method is based on default setting.The obtained meshing of peltonbucket,had 38982 number of nodes. gr Fig.4 Velocity diagram of Pelton Bucket In this present work, a force according to each operating condition (discharge and speed) is applied on the splitter and the constraint is in the form of fixed face of support of the bucket Fig.3. Solid Model of Pelton Bucket 14 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 The results of the simulation have been presented in the form of contour plots obtained through the APDL software for the three principle as well as Von Mises stress. Fig.5 Boundary Conditions A Total number of 9 operating conditions have been considered for the analysis. TABLE.I Forces on Pelton Bucket rates Speed 700 820 rpm rpm discharge 100 lit/sec 2947 2491 N N 123 lit/sec 3624 3064 N N 150 lit/sec 4420 3736 N N Fig.6 Ist Principal Stress distribution for discharge Q = 123 lit/secand speed N= 820 rpm at different flow 900 rpm 2185 N 2687 N 3277 N Force on bucket is given by- F = ρ Q ( Vu1-Vu2) C.Post- Processing- results have been plotted in the form of contour plots of following: 1st Principal Stress 2nd Principal Stress 3rd Principal Stress Von Mises Equivalent Stress. Fig.7 IInd Principal Stress distribution for discharge Q = 123 lit/sec and speed N= 820 rpm IV.RESULT 15 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Fig.8 3rd Principal Stress distribution for discharge Q = 123 lit/sec and speed N= 820 rpm A study of contour plots for principle stress with respect to blade surface (Fig 5.1) shows that the value of 1stprinciple stress is more or less constant throughout the blade surface except for a triangular region near the joint of the blade surface and the support. Thereafter from the joint to the fixed edge of the support the stress increases steadily reaching a maximum value at the edge. This is probably because the jet of fluid returns back after reaching the end of blade surface hence creating large stresses at the joint of the jet and support. 2nd Principle stress (Fig 5.2) is constant throughout the blade surface as well as the support except at the fixed edge of the support where it shows higher stress. As the jet bifurcates at the splitter in two opposite direction hence the axial thrust gets nullified. 3rd Principle stress also shows (Fig 5.3) uniform stress all along the blade surface as well as the support except at the location where the jet strikes and at the fixed edge of the support. Fig 9 Von MisesStress distribution for discharge Q = 123 lit/sec and speed N= 700 rpm . A study of contour plots of Von Mises stress show that in general the Von mises stresses are very low in the region between the lip section and the point of application of jet. The stress increases in a narrow zone from the point of application of jet. This zone of high stress widens gradually as we move towards the fixed end of blade and simultaneously the magnitude of stress also increases towards the fixed end. This zone of high stress inside the bucket is observed to follow the same pattern as that of the jet flow. Initially it is a narrow band which spreads out near the junction where the jet returns from the blade surface. Within this wide zone also the maximum stress is present in the centre which happens to be the location of the connection of the support. This increase in the stress is probably due to the turning of the jet which creates load on the blade surface. When we consider the stress in the support then it is seen that the stress increases continuously from the connection with blade to the fixed end. This is obvious due to the cantilever action. Similarly if we consider the stress variation across the depth of the support then maximum stress are observed at the both bottom and top surfaces with minimum stress at the center region. This is also due to cantilever action. It is observed that for a given discharge as the rotational speed is increase there is 16 ELK Asia Pacific Journals – Special Issue corresponding decrease in the magnitudes of all three principle stresses. The reduction of all three principle stresses and Von-mises stress with speed is shown in table below Table II. Variation of Stress with speed Speed 900 rpm 820 rpm 700 rpm Discharge Stress (N/m2) Von mises Stress 1st Principle Stress 2nd Principle Stress 3rd Principle Stress Von mises Stress 1st Principle Stress 2nd Principle Stress 3rd Principle Stress Von mises Stress 1st Principle Stress 2nd Principle Stress 3rd Principle Stress Proc. Of the Int. Conf: ARIMPIE-2015 The reason behind this is already discussed while explaining the contour plots. It is observed that at higher speed (900 rpm), maximum stress is nearly same for all discharges. The value of this stress is- about 13000 N/m2 for 1st principle stress, 6000 N/m2 for 2nd principle stress and 4500 N/m2 for 3rd principle stress. At lower speed (700rpm), there is very less variation in stress for 100 lit/sec and 123 lit/sec. This variation is about 14000N/m2 to 16000 N/m2for 1st principle stress, 8500N/m2 to 10000N/m2 for 2nd principle stress and 6500N/m2 to 7500 N/m2for 3rd principle stress. The stress increases abruptly for 150 lit/sec. However in all cases the maximum principle stress is well below the yield limit of the material (650 MPa). 100 lit/sec 8685 123 lit/sec 9628 150 lit/sec 11339 11022 12445 14408 5137 5798 6713 3928 4415 5118 10578 13522 17091 13501 17323 21857 6289 8072 10187 4784 6162 7793 Fig 10. Variation of von mises stress with speed it is also observed that for a given discharge as the rotational speed is increased, there is a corresponding decrease in the magnitude of the stress. 14259 16746 22823 18361 21359 29137 8556 9955 13580 6527 7617 10386 The principle stress vs speed graphs (fig 5.14 to 5.16) show that 1stprinciple stress is higher than 2nd and 3rd principle stresses. V.CONCLUSION The reason for this decrease in stress with increase in rotational speed is probably due to the fact that as the speed increases the contact time of the jet on the blade decreases thus reducing the stress. REFERENCES [1] Argyris J.H. (1954). Recent Advances in Matrix Methods of Structural Analysis, Pergamon Press, Elmsgford, NY. 17 ELK Asia Pacific Journals – Special Issue [2] Binaya K.C., BholaThapa, 2009, Pressure Distribution at Inner Surface of Selected Pelton Bucket For Micro Hydro, Proc. Of the Int. Conf: ARIMPIE-2015 [9] R. Angehrn, Safety Engineering for the 423 MW-PeltonRunners at Bieudron, August 6 – 9, 2000 VATech ESCHER WYSS, Zurich, Switzerland [3] Clough R.W., September 8-9 1960, ’’The Finite Element Method in Plane stresses Analysis’’ ,Proceeding of 2nd ASCE Conference on Electronic computation, Pittsburg, P.A,. [4] Hirt C.W., 1981, Nichols B.D, Volume of fluid method for dynamics of free boundaries, journal of computational physics [5] I.U. Atthanayake, Department of Mechanical Engineering, October 2010, The Open University of Sri Lanka Nawala, Sri Lanka.”Analytical Study On Flow Through a Pelton Turbine Bucket Using Boundary Layer Theory”, International Journal of Engineering & Technology IJET-IJENS Vol:09 No:09 [6] Mr. Patel Dhaval, Mr.GajeraChintan, Mr.ValaKuldip, 2010,“Stress & Experimental Analysis Of Simple And Advanced Pelton Wheel. [7] Nakanishi Y., Kubota and Shin T.,2002, “Numerical simulation of flows on pelton bucket by partial method: flow on a stationary rotating flat plate, ” proceeding of 21th IAHR symposium, Lausanne, Sept. 9-12 [8] Roache, P.J. (1972). Computational Fluid Mechanics, Hermosa Publishers Albquerque, NM 18 ELK Asia Pacific Journals – Special Issue 4. SHIPS STEERING AUTOPILOT DESIGN BY NOMOTO MODEL Pradeep Mishra M.Tech student Mechanical Engg Dept DIAT (DU),Pune Dr. S K Panigrahi Professor and HOD Mechanical Engg Dept DIAT (DU),Pune Lt Cdr Swarup Das Faculty & Project Guide MILIT ABSTRACT Ships manoeuvring can be automated by using the autopilot system. The marine autopilot system design is based on the mathematical model of steering dynamics. Here in the present paper a study on Nomoto model has been undertaken for its selection for the ships steering dynamics. Choice of selection of the model with respect to fundamental properties of first and second order models has been considered. Effectiveness of the models has been assessed on the basis of main properties of Nomoto model i.e. controllability, observability, identifiability. Further, reasonability of selecting state space model and the transfer function model for the study of different properties has been explained. It is proven that the first order model is controllable and observable whereas the second order model is conditionally controllable. Zero appearing in the transfer function model is found responsible for the overshot behaviour which indicates that the selection of second order model is suitable if the overshoot behaviour has to be studied. First and second order model are identifiable with the ill conditioning problem associated with the latter. hence the first order model is suitable for autopilot applications. Model reductions from fourth order to second and then first order model has been undertaken describing sway-yaw-roll dynamics and bode plots for these models are drawn to show the changes in frequency response due to model simplification. Proc. Of the Int. Conf: ARIMPIE-2015 1. INTRODUCTON This paper is concerned with fundamental properties like controllability, observability, identifiability of Nomoto first and second order model. State space model for Nomoto first and second order model has been derived and solved to find controllability, obeservability because state space model represent non controllable as well as non observable modes along with the observable and controllable modes whereas the transfer function model represents only controllable and observable modes, non controllable and non observable modes are cancelled in transfer function model. Subsequently the system overshoot with respect to Nomoto second order model is explained. Overshoot is caused due to sway coupling effect on yaw rate which is represented by zero and a high frequency pole in Nomoto second order model i.e.(1+T3S) and (1+T2S).However the ill conditioning problem due to near cancellation of zero and poles T3≈T2 makes second order model less preferable for autopilot design. In this paper an alternative approach is suggested for adaptive autopilot system which comprises of keeping the zero of second order model which is important for the study of overshoot phenomenon at the same time keeping T3 fixed and varying K, T1,T2 to avoid the ill conditioning problem .further with the help of Bode plots for forth ,second, first order model it is proven that why simplification of fourth order model to second order model is not significant because the plots are almost similar except humps in the fourth order plot. That means coupling effect of roll mode on yaw motion is negligible but effect of sway couple on yaw motion which is represented by second order bode plot cannot be neglected. Step input response to Nomoto models is also studied. 2. SHIP STEERING DYNAMICS MODEL SIMPLIFICATION Ship response in waves is considered as 6 degree of freedom motion in space. For manoeuvring study 3 dof motion namely surge ,sway, yaw is considered but for heavy vessels effect of roll 19 ELK Asia Pacific Journals – Special Issue cannot be neglected hence our study will revolve around 4 dof motion description namely surge, sway, yaw and roll. Here fourth order transfer function relating yaw rate to rudder angle is derived. Further simplification to second order and first order model is also described Proc. Of the Int. Conf: ARIMPIE-2015 a1V = a2ϕ+ a3r + a4δ (4) b1ϕ= b2V + b3r + b4δ (5) c1r = c2V + c3ϕ+ c4δ (6) where a1 = (m – YV)S – YV a2 = YṖS² + YPS + Y ϕ (7) a3 = YṙS + Yr + mu0 a4 = Yδ Figure 1 coordinate system. Sway-yaw-roll (8) (9) (10) b 1 = (IX – KṖ)S² – KPS + mgG̅M̅ (11) b 2 = KV̇S + KV (12) b 3 = KṙS + Kr (13) b4 = Kδ (14) c1 = (IZ – Nṙ)S – Nr (15) c2 = NV̇S + NV (16) c3 = NṖS² + NPS + N ϕ (17) c4 = Nδ (18) motion m(ύ + u0r) = Yύύ+ YVV + Yϕϕ+ YṗṖ + Y PP + Yrr + Yṙ ṙ+ Yδδ (1) IX ̇ϕ̇= KPP + KṗṖ – mgG̅M̅ϕ+ KVV+ K ύύ + Krr + Kṙ ṙ + Kδδ(2) IZ ̇Ψ̈ = Nrr + Nṙ ṙ + Nϕ ϕ+ NPP+ N ṗṖ + NVV + Nύύ + Nδδ (3) where YV, Yύ , …, indicate the hydrodynamic coefficients; for instance, YV indicates the derivative of the sway force Y to the sway speed V evaluated at the reference condition; m is the mass of the ship; IX is the moment of inertia about the x-axis; IZ is the moment of inertia about the z-axis; V is the sway speed; u is the surge speed; r is the yaw rate; Ψ is the heading angle defined by ψ = r ; p is the roll rate; φ is the roll angle defined by φ = p and GM is the metacentric height, which indicates the restoring capability of a ship in rolling motion. Taking the Laplace transform of Eqs. (1)-(3) and rearranging, we have After eliminating the sway speed V and roll angle ϕ from Eqs. (4)-(6), the following transfer function relating the yaw rate r to the rudder angle δ can be obtained: r = a1(b1C4 + b4C3) + a2(b4C2 – b2C4) + a4(b1C2 + b2C3) δ a1(b1C1 – b3C3) – a2(b2C1 + b3C2) – a3(b1C2 + b2C3) (19) It can be easily verified that the numerator of Eq.19 is third order in S, while the denominator is fourth order in S. Hence, Eq. (19) can be expressed in the following form r = K(1 + T3S)(S ²+ 2ηωS +ω² δ (1 + T1S)(1 + T2S)(S ² + 2ξωnS +ω²n (20) where the quadratic factors are due to the coupling effect from the roll mode on the yaw 20 ELK Asia Pacific Journals – Special Issue rate. The zero (1+ T3S) and the pole (1 + T2S) are due to the coupling effect from the sway mode on the yaw dynamics. If the roll mode is neglected, Eq. (20) can be further reduced to the following form r = K(1 + T3S) δ (1 + T1S)(1 + T2S) (21) Eq. (6) is known as the second order Nomoto model, where K is the static yaw rate gain, and T1, T2 and T3 are time constants. In practice, because the pole term (1 + T2S) and the zero term (1 + T3S) in Eq. (21) nearly cancel each other, a further simplification of Eq. (21) can be done to give the first order Nomoto model r = ___K____ δ (1 + TS) (22) Where T = T1 + T2 - T3 First order Nomoto model is widely employed in autopilot design and yaw dynamics which is characterised by parameters K and T can be determined by manoeuvring tests. Through first order Nomoto model a transfer function relating ships heading(Ψ) to rudder angle(δ) can be easily calculated by adding 1/S to transfer function model. 3. CONTROLLABILITY & OBSERVABILITY OF NOMOTO MODELS Fundamental properties of Nomoto first order model has been assessed here wrt state space model because it represents uncontrollable as well as unobservable modes whereas identifiability property is assessed wrt transfer function model. Eq (22) can be expressed in time domain asTr̈ + r = Kδ (23) With the notation Ψ̈ = r (24) T Ψ̈ Ψ Kδ (25) Eq 24 and 25 can be arranged in the standard state space form ̇x = Ax + Bu y = Cx (26) (27) Proc. Of the Int. Conf: ARIMPIE-2015 where x = [Ψ ; r]^T u=δ y=Ψ (28) (29) (30) and A= B= [0 ; K/T]^T C= [1 0] According to linear system theory, the system defined by Eqs. (12) is controllable if the following matrix U is of full rank U = [B AB] = and the system is observable if the following matrix V is of full rank V = [C CA]^T = Following can be observed from above 1. First order model is controllable and observable. Here controllability means that ships heading and rate of turn can be controlled via application of rudder. 2. Observability indicates that system states ships heading and rate of turn can be obtained by measured data. 3. Identifiability represents that the parameters K and T can be determined from i/p (rudder angle) and o/p (yaw rate) which is equivalent to fitting first order model to rudder angle and yaw rate to find K and T. Hence online estimation of model parameters K and based on rudder angle and yaw rate is possible and adaptive control strategy can be implemented. Similar to the discussion about first order model, for the second order model sway to rudder transfer function can be achieved by 21 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 neglecting the roll mode then subsequently eliminating the yaw rate r from eq (1) and (3) V = Kv(1 + TvS) δ (1 + T1S)(1 + T2S) Step Response (31) 16 14 where Kv =static sway gain coefficinet Tv = sway time coefficient 12 4. 5. 6. If the system is controllable then state variables Ψ,r,V should be able to move independently via application of rudder δ.It is thus inferred that for the system to be controllable Tv ≠ T. It can be easily verified that the system is observable that means that all the states (Ψ, r, v) can be reconstructed from the measured heading angle Ψ. For identifiability K , T1,T2,T3 should be able to determined via δ and r.However if T2=T3 zero and pole will cancel each other and ill conditioning problem will occur. Hence for identifiability T2 ≠ T3. Amplitude 10 8 6 4 2 0 0 50 100 Time (sec) 150 200 250 Figure 2 Unit step response T3=500 Second order Nomoto model is employed where overshoot phenomenon due to large rudder angle turning manoeuvre is to be studied. however it creates an ill conditioning problem due to near cancellation of zero and a high frequency pole. Step Response 12 10 8 SYSTEM Effect of zero term (1+T3S) on second order Nomoto model by varying values of T3 and keeping T1,T2,K fixed and applying unit step response has been studied here. Overshoot is observed when T3 value is higher, for low values of T3 overshoot are not visible. In order to study overshoot behaviour the second order Nomoto model is employed. In second order model, the overshoot is visible when the zero is on right side of poles and near the imaginary axis. From the equations above and unit steep response curves it is evident that the overshoot is due to sway coupling effect on yaw rate. It can be said that the first order model is relatively simple, doesn’t have ill conditioning problem and applied for small rudder angle yaw dynamics, it requires identification of only two parameters hence it is the first choice for autopilot design. 6 4 2 0 0 20 40 60 80 100 120 Time (sec) Figure 3 Unit step response T3=250 Step Response 10 9 8 7 6 Amplitude OF Amplitude 4. BEHAVIOUR OVERSHOOT 5 4 3 2 1 0 0 20 40 60 Time (sec) 80 100 120 Figure 4 Unit step response T3=100 22 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 r = 0.0033Sᶾ-0.0004S²-0.0002S-0.000079____ δ S 4 + 0.1913S ᶾ + 0.0705S²+ 0.0069S +0.0001 (32) S²+ 0.1213S +0.00304 (33) bode dig of second order -20 -30 Magnitude (dB) Here an alternative approach is suggested for an adaptive autopilot implementation basing upon the second order Nomoto model. Since the zero of the transfer function helps better describing the yaw dynamic overshoot behaviour, its structure is retained and the parameter is fixed at a value determined off-line from input-output experiment data. A fourth order linear state space model representing the sway-yaw-roll modes of motion will be used as the nominal model in constructing the corresponding yaw to rudder transfer function. Further simplification to the second order Nomoto model and the first order Nomoto model will also be presented. Using MATLAB, the transfer function of the referred state space model , from i/p rudder to the output yaw rate r is obtained as δ -40 -50 -60 -70 180 Phase (deg) 5. MODEL REDUCTION AND BODE PLOTS 135 90 -3 10 -2 -1 10 0 10 10 1 10 Frequency (rad/sec) Figure 6 Second order model further by neglecting the sway coupling effect on yaw rate ,resulting transfer function is reduced to first order model r = 0.049__ δ 1+ 17.78S (34) Bode Diagram -20 Bode Diagram -25 -30 -40 Magnitude (dB) Magnitude (dB) -30 -50 -60 -35 -40 -45 -50 -55 180 Phase (deg) Phase (deg) -70 180 135 135 90 -3 10 -2 10 Frequency (rad/sec) -1 10 0 10 bode dig first order model Figure 7 First order model 90 -3 10 -2 10 -1 10 0 10 1 10 Frequency (rad/sec) Figure 5- Fourth order model By neglecting the roll mode the following transfer function can be obtained and fourth order model is reduced to second order model. r = 0.0033S -0.00015__ Bode plots representing frequency domain yaw response and comprising magnitude and phase plots for above mentioned transfer functions are drawn wrt fourth, second, first order model. Plots for fourth and second order models are almost similar except the presence of humps in the fourth order model plot. However the first order model plot is significantly different than 23 ELK Asia Pacific Journals – Special Issue the first order plot in the magnitude and phase. Based on the observation of above figures, it can be concluded that the effects of model reduction from fourth order to second order is not significant ;namely the coupling effects of roll mode on yaw motion is negligible. However simplification of second order model to first order model poses serious challenges and throws implication of neglecting effect of sway couple on yaw rate which is a very significant aspect and hence cannot be undermined. Hence it is justified to use second order Nomoto model to represent the behaviour of fourth order model. 7. CONCLUSION The first order model is relatively simple, doesn’t have ill conditioning problem and applied for small rudder angle yaw dynamics, it requires identification of only two parameters hence it is the first choice for autopilot design, Second order Nomoto model is employed where overshoot phenomenon due to large rudder angle turning manoeuvre is to be studied. Since the second order Nomoto model includes the coupling effect from sway to yaw mode, it introduces a zero and high frequency pole into the transfer function which contribute in the overshoot tendency. However the ill conditioning problem with the second order model due to near cancellation of zero and pole prevail over the improvements gained in the modelling potential. An approach that retains the zero and at the same time avoids the ill conditioning problem has been proposed. The state space counterparts of the first order model is found to be controllable and observable, hence the state feedback and output feedback controllers can by successfully implemented. The state space counterpart of second order model is observable but conditionally stable (when Tv=T).Bode plots with respect to model simplification from fourth order to second and first order are depicted to show the errors and differences due to model simplification. REFERENCES Proc. Of the Int. Conf: ARIMPIE-2015 1. Nomoto, K., Taguchi, K., Honda, K. and Hirano, S., “On the Steering Quality of Ships,” International Shipbuilding Progress, Vol. 4, pp. 354-370 (1957). 2. Norrbin, N.H., “On the Design and Analysis of the Zig-Zag Test on Base of Quasilinear FrequencyResponse,” Technical Report No. B140-3, The Sweden State Shipbuilding Experimental Tank (SSPA),Gothenburg, Sweden (1963). 3. Astrom, K.J. and Kallstrom, C.G., “Identification of Ship Steering Dynamics,” Automatica, Vol. 12, pp. 9-22 (1976). 4. Hwang, W.Y., “Cancellation Effect and Parameter Identifiability of Ship Steering Dynamics,” International Shipbuilding Progress, Vol. 26, No. 332, pp. 90-120 (1982). 5. Zhou, W.W., Cherchas, D.B. and Calisal, S., “Identificationof Rudder-Yaw and RudderRoll Steering Modelsby Using Recursive Prediction Error Techniques”, Optimal Control Application and Methods, Vol. 15, pp.101-114 (1994). 6. Fossen, T.I., “Guidance and Control of Ocean Vehicles,” John Wiley and Sons, NY (1994). 7. Tzeng and Lin “Adaptive ship steering autopilot design with saturating and slew rate limiting actuator” International Journal Of Adaptive Control And Signal Processing (2000) 8. Viorel Nicolau “The Influence Of The Ship’s Steering Machine Over Yaw And Roll Motions” The Annals Of "Dunarea De Jos" University Of Galati (2003) 9. L. Morawski, J. Pomirski and A. Rak “Design Of The Ship Course Control System” International Design Conference – (2006) 10. Tristan Perez “Ship Motion Control” Springer-Verlag London Limited (2005) 11. S.Hammoud “Ship motion control using multi controller structure” Journal of Maritime Research (2011) 24 ELK Asia Pacific Journals – Special Issue 5. MATERIAL SELECTION IN BEARING INDUSTRY USING MULTI CRITERIA BASED TOPSIS METHODOLOGY Proc. Of the Int. Conf: ARIMPIE-2015 comprising of all possible alternatives along with their respective combinations of attributes are demonstrated in order to validate the effectiveness and flexibility of the model. I. Mr. J. S. Karajagikar Asst. Professor Dept. of Production Engineering & Industrial Management College Of Engineering, Pune Mr. R. R. Manekar Dept. of Production Engineering & Industrial Management College Of Engineering, Pune Abstract— Decisions are made in the best interest of an organization and effective decision making is the vital factor in organizational growth. Selection of appropriate bearing materials for diverse applications is one of the hardest tasks in any bearing manufacturing industry. Material selection, the process of determining the suitable material which provide better performance, quality, durability and efficiency of bearing plays a key role in bearing manufacturing. A systematic and efficient approach towards material selection is necessary in order to select the best alternative for a required bearing application. In other words bearing material selection from among many alternatives on the basis of many attributes is a Multiple Criteria Decision Making problem. This paper proposes an integrated decision making approach based on the various attributes of an alternatives of the bearing material by using one of the most popular decision making tool known as TOPSIS(Technique for Order Preference by Similarity to Ideal Solution). The model will help managers and engineers to reach a consensus on material selection for specific application of bearing. The framework of TOPSIS is demonstrated by using various bearing material alternatives available under each category of bearing steel and having different chemical composition for each alternative which are known as attributes. Four major categories of bearing material each INTRODUCTION While selecting materials for engineering applications, a clear understanding of the functional requirements is required and various important attributes need to be considered. Material selection attribute is defined as an attribute that influences the selection of material for given application. The attributes of material contributes at great extent in defining its physical, chemical, mechanical, manufacturing properties. Thus the selection among the alternative materials which is meeting the required properties on the basis of two or more attributes is multiple criteria decision making (MCDM) problem. The selection decisions are complex as material selection is more challenging today. There is need for simple, systematic and logical methods or mathematical tools to guide decision makers in considering a number of selection attributes and their interrelations. The objective of any material selection procedure is to identify appropriate selection attributes and obtain the most appropriate combination of attributes in conjunction with real requirement. Thus, efforts need to be extended to identify those attributes that influence material selection for a given engineering application to eliminate unsuitable alternatives and to select most appropriate alternative using simple and logical methods. In industries that are concerned with large scale production the raw materials and component parts possess huge share of total product cost. In such case purchasing department can play a key role in cost reduction. So, MCDM tools and techniques can also help purchase department in process of cost minimization by selecting appropriate material which is not over priced and also which can be able to achieve the desired attributes in the end products and can fulfill the actual and practical needs of the end products. Material selection process is one of the most significant variables, which has direct impact on the performance of an organization. As organization becomes more 25 ELK Asia Pacific Journals – Special Issue and more dependent on the material for better results of end products, the direct and indirect consequences of poor decision making will become more critical. The nature of this decision is usually complex and unstructured. MCDM problems involves tradeoffs among the criteria’s that involve both quantitative and qualitative factors, which may also be conflicting. In this paper as considering every criteria for selection of material was quite complex, hence with the consent of experts and their relevant literature we can recognize variables and effective criteria’s in material selection, with regards to this point the main and important criteria have been extracted by expert judgement. Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was first developed by Yoon and Hwang and it is one of the most popular and simplest MCDM tool. The rank of each type of material is determined by implementing TOPSIS method in this paper. TOPSIS has been a favorable technique for solving multi criteria problems. This is mainly due to reasons like its concepts are much simpler and easy to understand and also it requires less computational efforts unlike other MCDM methods like AHP and hence can be applied easily. II. PROPOSED METHODOLOGY The proposed methodology for selection problem, composed of method, consists of following steps: material TOPSIS Identify the criteria’s to be used in the model. Formation of decision matrix consisting of alternatives and criteria’s. Evaluation of alternatives with TOPSIS and determination of the final rank. In the first step with the help of going over expertise of experts we try to recognize variables and effective criteria in material selection and the criteria which will be used in their evaluation is extracted. Thereafter decision matrix is composed comprising of alternatives and criteria, with criteria on columns and alternatives on rows. Finally alternatives are evaluated and ranks are determined using TOPSIS method. Proc. Of the Int. Conf: ARIMPIE-2015 Schematic diagram of the proposed model for material selection is provided in Figure 1. Figure 8: Schematic model for TOPSIS Methodology. III. TOPSIS METHODS TOPSIS method was introduced for the first time by Yoon and Hwang and was appraised by surveyors and different operators. As large number of potential available vendors in the current marketing environment, a full ANP decision process becomes impractical in some cases. To avoid an unreasonably large number of pair wise comparisons we choose TOPSIS as the ranking because of its concepts ease of use. Also ANP is adopted simply for the acquisition of the weights of criteria. A general TOPSIS procedure for TOPSIS method is described below: Step 1: Establish a decision matrix for the ranking. The structure of the matrix can be expressed as follows: 26 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Where m= 1 to i represents various alternatives and n= 1 to j represents various criteria and values entered into matrix represents performance rating of each alternative with respect to each criterion. Step 2: Obtain a Normalized decision matrix (Mij). The normalized values (mij) of normalized decision matrix are calculated as: Step 5: Determine Positive and Negative Ideal Solutions: Vj+ = {V1+......Vn+} = {(Max Vij j ε J)} for positive criteria. = (Min Vij j ε J’)} for negative criteria. Vj- = {V1-......Vn-} = {(Min Vij j ε J)} for positive criteria. = {(Max Vij j ε J’)} for negative criteria. Where i = 1, 2, 3…..m Step 3: Standardize matrix to assign weights: Matrix after standardization is represented as: Where J is associated with positive criteria and J’ is associated with the negative criteria. Note: Positive and negative criteria are also termed as Benefit and Cost criteria. As their names suggest, benefit criteria is the one which represents beneficial qualities in that material on the other hand cost criteria represents the qualities which are non-beneficial. Hence a reliable expertise is needed to be taken while deciding that the whether any particular criteria is to considered as benefit criteria or cost criteria. Step 6: Obtain separation measures of each alternative from Ideal One. Where j = 1, 2, 3……n Weights are assigned to criteria as: 𝑾𝒋 = ∑ 𝑿𝒋 𝒏 Where n = No of alternatives in decision matrix. Where Si+ is the positive separation measure from positive ideal solution Vj+. Step 4: Obtain weighted normalized decision matrix: Weighted normalized obtained as: decision matrix is 𝑽𝒊𝒋= 𝑿𝒊𝒋 ∗ 𝑾𝒋 Each criteria is multiplied by its corresponding weight assigned. Where Si- is the negative separation measure from negative ideal solution Vj-. 27 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 appropriate chemical composition is a decision making process out of several available alternatives. By application of TOPSIS methodology we tried to find out the best available material alternative in each class of bearing steel. Step 7: Rank alternatives in descending order by finding relative closeness (Pi) of particular to Ideal Solution. ) III. The first step starts with the developing of decision matrix, although the criteria considered in the evaluation purpose are essential for particular class of bearing steel but the criteria may change as per the class of bearing steel and some other criteria may also be required to replace, added into the current criteria as per the need. The detailed TOPSIS process for material selection problem in bearing steel industry is described below. NUMERICAL PROBLEM For the application purpose of this methodology, we solved and applied this technique for material selection problem in bearing industry. There are numerous types of material available having different chemical composition according to each class of bearing steel. This material selection is very critical process as the material should retain appropriate physical as well as chemical properties as required after the bearings have been manufactured by using these material. Hence selecting a material having an Step 1: Developing a decision Matrix C Si Mn SUJ2 1.1 0.35 0.5 SUJ3 1.1 SUJ5 52100 P S Cr Mo 0.025 0.025 1.6 0.08 0.7 1.15 0.025 0.025 1.2 0.08 1.1 0.7 1.15 0.025 0.025 1.2 0.25 1.1 0.35 0.45 0.025 0.025 1.6 0.1 Grade 1.05 0.75 1.25 0.025 0.025 1.2 1 0.1 Grade 1.1 3 0.35 0.9 0.025 0.025 1.5 0.3 Step 2: Obtain Normalized Decision Matrix (𝐌𝐢𝐣). 𝒎𝒊𝒋= SUJ2 C 0.41 Si 0.25 Mn 0.21 𝑹𝒊𝒋 𝟐 (∑𝒎 𝒊=𝟏 𝑹𝒊𝒋 ) P 0.40 S 0.40 Cr 0.46 Mo 0.18 28 ELK Asia Pacific Journals – Special Issue SUJ3 SUJ5 52100 Grade 1 Grade 3 Proc. Of the Int. Conf: ARIMPIE-2015 0.41 0.41 0.41 0.50 0.50 0.25 0.49 0.49 0.19 0.40 0.40 0.40 0.40 0.40 0.40 0.35 0.35 0.46 0.18 0.58 0.23 0.39 0.54 0.534 0.40 0.40 0.35 0.23 0.41 0.25 0.38 0.40 0.40 0.43 0.69 Step 3: Standardizing Matrix to assign weights 𝑿𝒊𝒋= C Si Mn P S Cr Mo Sum SUJ2 0.17 0.10 0.09 0.17 0.17 0.19 0.07 2.34 SUJ3 0.14 0.18 0.17 0.14 0.14 0.12 0.06 2.76 SUJ5 0.13 0.16 0.15 0.12 0.12 0.11 0.18 3.15 52100 Grade 1 Grade 3 0.17 0.10 0.08 0.17 0.17 0.19 0.09 0.13 0.18 0.18 0.14 0.14 0.12 0.08 2.37 2.86 0.13 0.08 0.12 0.13 0.13 0.14 0.23 3.00 Wj 0.15 0.13 0.13 0.15 0.15 0.15 0.12 SUJ2 C 0.17 Si 0.10 Mn 0.09 P 0.17 S 0.17 Cr 0.19 Mo 0.07 0.14 0.13 0.17 0.18 0.16 0.10 0.17 0.15 0.08 0.14 0.12 0.17 0.14 0.12 0.17 0.12 0.11 0.19 0.06 0.18 0.09 0.13 0.18 0.18 0.14 0.14 0.12 0.08 0.13 0.08 0.12 0.13 0.13 0.14 0.23 0.90 0.83 0.82 0.90 0.90 0.90 0.74 SUJ3 SUJ5 52100 Grade 1 Grade 3 Sum 𝑴𝒊𝒋 ∑𝒏 𝒋=𝟏 𝑴𝒊𝒋 Here weights are assigned to each attribute as per its relative importance with corresponding alternative material. 29 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Step 4: Obtain Weighted Normalized decision matrix. 𝑽𝒊𝒋 = 𝑿𝒊𝒋 ∗ 𝑾𝒋 SUJ2 SUJ3 SUJ5 52100 Grade 1 Grade 3 C 0.02 Si 0.01 Mn 0.01 P 0.02 S 0.02 Cr 0.02 Mo 0 0.02 0.01 0.02 0.02 0.02 0.01 0.02 0.02 0.01 0.02 0.01 0.02 0.02 0.01 0.02 0.01 0.01 0.02 0 0.02 0.01 0.02 0.02 0.02 0.02 0.02 0.01 0.01 0.02 0.01 0.01 0.02 0.02 0.02 0.02 Step 5: Positive & Negative Ideal Solutions. Vj+ 0.019 0.02 0.02 Vj- 0.02 0.01 0.01 Here we are considering Carbon (C) and Sulphur (S) as negative criteria because additionaly as carbon content increases steel becomes increasingly responsive to heat treatment which is 0.02 0.01 0.019 0.029 0.02 0.02 0.016 0.008 also not good as this may lose the elasticity in the material. Also excess amount of Sulphur causes material to become detrimental to the hot forming properties. Step 6: Obtain Separation measures from Ideal One. 𝑚 (𝑉𝑖𝑗 − 𝑉𝑗+)2 )^0.5 𝑆𝑖+ = ( 𝑗 =1 SUJ2 𝑆𝑖− = Si+ 0.0272817 0.0237935 SUJ3 0.0170125 SUJ5 𝑚 0.0263799 52100 Grade 1 ( (𝑉𝑖𝑗0.0225938 − 𝑉𝑗−)2 )^0.5 0.0192855 Grade 𝑗 =1 3 SUJ2 SUJ3 Si0.0153346 0.0201986 30 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 SUJ5 52100 Grade 1 Grade 3 0.0226527 0.0152536 0.0219704 0.0234641 Step 7: Rank the alternatives by finding relative closeness (Pi) to ideal solution. 𝑆𝑖− 𝑃𝑖= (𝑆𝑖++𝑆𝑖−) SUJ2 SUJ3 SUJ5 52100 Grade 1 Grade 3 Pi 0.359829 0.459141 Rank 6 4 0.571097 0.366377 0.493006 0.548873 1 5 3 2 Thus from the rankings done using relative closeness co efficient (Pi), SUJ5 material has the best score amongst the six materials. Conclusion For bearing industry it is necessary to maintain the good level of chemical composition in the materials so that it its properties and quality are not compromised. By above mathematical treatment it is clear that the material selection for a bearing industry involves multiple criteria which show the important role in selection of material. Technique for Order Preference by Similarity to Ideal Solution is simple and understandable method for selecting a suitable material. Using this method we select the different alternatives according to the importance of different criteria. Thus, TOPSIS method used for different multi criteria decision problems in suitable manner. References [1] William Ho, Xiaowei Xu, Prasanta k. Dey. Multi-criteria decision making approaches for supplier evaluation and selection, European Journal of Operational Research [2] [3] [4] [5] [6] [7] (2010), Volume: 202, Issue 1, Publisher: Elsevier, Pages 16-24. Pragati Jain and Manisha Jain, Fuzzy TOPSIS Method in Job sequencing problems on machines of unequal efficiencies, Canadian Journal on Computing in Mathematics, Natural Sciences, Engineering and Medicine Vol 2 No 6, June 2011. Charles A Weber , John R Current, W C Benon. Vendor Selection criteria and methods, European Journal of Operational Research 50(1991) 2-18, North Holland. Shanian A, Savadogo O.,”TOPSIS” multiple criteria decision support analysis for material selection of metallic bipolar plates for polymer electrolyte fuel cell”, J Power Sources; Vol 159 No 10, pp 95-104, 2006. V. Rao, Decision making in the manufacturing environment: Using graph theory and fuzzy multiple attributes decision making methods. India: Springer series in advanced manufacturing, (2007). Shih,H. S., Shyur, H.J., & Lee, E.S An extension of TOPSIS for group decisionmaking. Mathematical and Computing Modeling, 45:801-803, (2007). Chen, Y., Kevin, W. LI & Xu, H., & Liu,S. A DEA-TOPSIS method for multiple criteria decision analysis in emergency management, Journal of Systems Sciences and System Engineering, 18(4):489-507, (2009). 31 ELK Asia Pacific Journals – Special Issue 6. DATA ACQUISITION AND MONITORING OF EMG (ELECTROMYOGRAM) SIGNALS Mrinal Jyoti Sarma Department of Electrical & Electronics Engineering Birla Institute of Technology, Mesra Ranchi, India
[email protected] Richa Pandey Department of Mechanical Engineering Birla Institute of Technology, Mesra Ranchi, India
[email protected] Abstract— The paper presents a simple, low cost and effective circuit which is designed for the acquisition and processing of EMG signals to finally interface with a working unit. The EMG signals are acquired by a data acquisition system, those signals are further conditioned to drive and monitor the functioning of a movable unit. The signal conditioning unit comprises of instrumentation amplifier, low pass and high pass filter, rectifier, amplifier and comparator was developed for conditioning the acquired EMG signals. A virtual model of the acquisition system is done in PSIM (powersim), afterwards it is designed in real time. Finally at the end the design circuit was interfaced with a motor by using arduino microcontroller. Keywords— EMG(electromyogram)signal, instrumentation amplifier, Signal conditioning, PSIM, arduino microcontroller. I. INTRODUCTION EMG signals are the electrical potential generated due to the contraction of muscles. In medical science EMG signals are use to examine the muscles. Those signals have particular characteristics by seeing which doctors can identify the condition of muscles. From the beginning of medical science studies upon EMG signals are going on, now in 21st century due to Proc. Of the Int. Conf: ARIMPIE-2015 the advancement in electronic components it is become easier, but those equipments are still costly. Our main intension is to design a low cost EMG signal acquisition and processing unit which can replace those costlier products. We can use those processed EMG signals to show some ideas which can make human life smooth or may useful to engineering world as well as in human machine interface [17]. For example we can design prosthetic hand [1] [2] or leg [3]; also the processed signals can be use in controlling of wheel chair [4], which will be helpful for physically challenged people. In our work we control a motor by monitoring the EMG signals. To interface the EMG signals with motor arduino microcontroller is used. The use of microcontroller makes the system more versatile. The EMG signals generated in our body are having very low amplitude and exist for very small duration [5]. This signal also contains noises, those are mainly arises from the electrode skin interface, built in noise in the electronic components and noises due to electromagnetic radiation from surrounding [6]. The acquired signals should be process very carefully before use in any application. That is why signal amplification and filtering plays vital role in processing of EMG signals [6] [7]. Analysis should be done in such a way that it doesn’t lose its originality but all the noise components should be removed. Works are still going on in accurate extraction of EMG signals. II. BASICS OF EMG SIGNALS a. What is EMG signal Central nervous system (CNS) is the control hub of all activity of our body. Whenever we need to accomplish any task, the central nervous system sends signals to the respective body part to perform that activity. For example, suppose we need to pull a heavy object, at that time the CNS will keep on sending signals to the arm muscles to produce required amount of force to pull that object. If the force is not sufficient then more number of muscles will join to increase the force. When any muscle is use to perform a task the ‘motor units’ are got excited [8]. A motor unit is nothing but the combination of cell body, 32 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 dendrite and axon. When a motor unit is in excited state exchange of ions occur through the plasma membrane of the neuron cells of the respective muscles [9]. Due to this exchange of ions a potential difference builds inside and outside of the plasma membrane. This type of potential difference from several neuron cell travels throughout the muscles and got superimpose with one another and give rise to EMG signals [10]. Thus the central nervous system maintain good coordination among the body muscles. b. Characteristics of EMG signals The EMG signals are of random in nature. Normally its frequency range varies from 10 Hz to 1000 Hz [11]. With this frequency range some part of ECG (electrocardiogram) and EEG (electroencephalography) are also included, so we choose dominating frequency range of the EMG signals which is from 50 Hz to 500 Hz [12]. Its amplitude varies from (-70mv) to around (40mv) [13] depending upon motor unit action potential (MUAP) [8]. The duration of EMG signals are depend upon age as well as muscles, table no.1 shows the variation of duration depending upon age and muscles. The EMG signals have basically three or four phases. Fig.1 shows normal EMG signal produce from muscles. TABLE I. VARIATION OF DURATION DEPENDING UPON MUSCLES AND AGE 1 Action potential duration depending upon age Age Biceps (ms) Triceps (ms) (years) 7.3-8.0 8.3-9.0 3-13 2 20-30 8.7-9.9 9.9-11.2 3 40-50 10.9-11.6 12.4-13.2 4 60-75 12.3-12.8 13.9-14.4 Serial no Fig. 1. Normal EMG signal III. EMG ELECTRODES Electrodes play a major role in the detection of EMG signals. The EMG signals generated in our body are having very low amplitude as well as duration, so if the electrodes don’t have good conductivity then it will affect the quality of the signals. There are mainly two types of electrodes available one is ‘inserted electrode’ and the other one is ‘surface electrode or skin electrode’. a. Inserted electrodes These electrodes are further split up in two categories ‘needle’ and ‘fine wire’ [8] and mostly use in medical purpose, for example someone is having neuromuscular disorder in that situation these electrodes are put into the particular muscles to detect the disorder. The main advantage of these types of electrodes is that they are having the small detection surface which enables them to pick up individual Motor Unit Action Potential (MUAP) [8] from the muscles and can explore the infected muscles. The main difference between the needle and fine wire electrode is that diameter of needle electrodes is more than that of fine wire, because it contains insulated detecting wire inside the needle, so they may cause pain to the patients. As the fine wire electrodes are smaller in diameter they can easily put and withdraw from the muscles and less painful than needle electrodes. 33 ELK Asia Pacific Journals – Special Issue b. Surface electrodes or Skin electrodes As the name specifies these electrodes are placed over the skin, they are non invasive. These are made up of highly conducting materials, so that they can conduct the low amplitude EMG signals. There are mainly two categories of these electrodes ‘active’ and ‘passive’ [8]. The active electrodes have a preamplifier attach with it. This pre-amplifier amplify the EMG signals before going to further steps and they are costly. But the passive electrodes don’t have a pre-amplifier [8], and they are reusable and disposable. These electrodes are basically made up of silver-silver chloride (Ag-AgCl). In our work we used passive electrodes as they are economical. IV. HARRDWARE DESCRIPTION This part describes the methodology behind the monitoring of EMG signals. The whole hardware part can be split up in two parts ‘EMG signal monitoring part’ and ‘actuator part’. In Fig.2 layout of the hardware part is shown. Proc. Of the Int. Conf: ARIMPIE-2015 instrumentation amplifier and set the gain around 50dB. The gain should not be high enough, because it may amplify the noise components also. The next stage is a HPF. As mention in the characteristics section, the frequency range of EMG signals varies from 50 Hz to 500 Hz. So this HPF has the cut off frequency of 50 Hz. This stage is followed by a LPF of cut off frequency 500 Hz. Fig.4 shows the output of the low pass filter. After the filtration stage a full wave rectifier is used to reshape the EMG signals, followed by a envelop detector and gain amplifier. In Fig.5 the output of envelop detector is shown. The amplifier has the gain of 50dB. This is basically used to boost up the EMG signals. The last stage is a comparator; it is having a threshold voltage. So whenever the EMG signals cross the threshold voltage the comparator will give constant output which will power up the next stage. Fig.6 shows output of the comparator (in PSIM) and Fig.9 shows the output of real time comparator. In all the stages except the instrumentation amplifier, we used LF 351 op-amp, as it is economical and it has the voltage range of +9 to -9, so suitable for our work. In Fig.3 (a) and (b) PSIM design of the hardware circuit is shown and Fig.8 shows the acquisition part. Fig. 2. Lay out of hardware a. Acquisition and monitoring part The first stage of the hardware part is instrumentation amplifier. This amplifier operates in differential mode [19]. Due to this differential mode it can cancel the noises which are common to both inputs. Actually with the EMG signals some frequency components of EEG (electroencephalography) [14] and ECG (electrocardiogram) [15] signals are also got super impose which act as noise. So the instrumentation amplifier should have good common mode rejection ratio (CMRR) [16]. In our work we choose INA 126P for Fig. 3(a). PSIM design of acquisition circuit Fig. 3(b). PSIM design of hardware circuit 34 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Fig. 4. Output of low pass filter (in PSIM) Fig. 7. Servomotor and DC motor driving circuits Fig. 5. Output of envelop detector (in PSIM) Fig. 6. Output of comparator (in PSIM) b. Actuator part This part describes how to control of the actuator part. The output of acquisition part is used to power up the motor driving part. This part consists of the circuitry part for the motor control or actuator. Mainly we designed a PWM (pulse width modulation) generator circuit by using 555 timer for a servo motor [17] and arduino microcontroller [18] based circuit for a DC motor. In Fig. 7 the driving circuits are shown. V. CONCLUSION The paper focuses basically on the design and development of a low cost prosthetic interface with surface EMG signals. Various electric hardware and software components were utilized to actuate the final circuit. The signal acquired could drive the actuator for various inputs and voltage range. The final movement of the motor can be interfaced to a running model for simulation. A new model has been designed to control the motor with the specified signals through microcontroller. The work is limited to drive a motor which could be realized for final modellind and prosthetic hand interface. This can be utilized for developing a low cost prosthetic part for a physically challenged person, as well as for other equipments like wheel chair, actuate DC motors and running of servo motor etc. 35 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Fig. 8. EMG signal acquisition part [8] [9] Fig. 9. Output of the comparator [10] References [1] [2] [3] [4] [5] [6] [7] M. Hildago, G. Tene, A. Sanchez, “Fuzzy Control of a robotic arm using EMG signals”. Ton Tai Pan, Ping Lin Fan, Huihua Kenny Chiang, Rong Seng Chang, Joe Air Jiang, “A myolelctric controlled partial hand prosthesis project”, IEEE transaction on education, Vol.47, No.3, August 2004. Md. Rokibul Islam, A.N.M. Mushfiqul Haque, S.N. Amin, K.S. Rabbani, “Design and development of an EMG driven microcontroller based prosthetic leg”, Bangladesh Journal of Medical Physics, Vol.4, No.1, 2011. Taslim Reza, S.M.Ferdous, Md. Nayeemul Hasan, Md. Rokonuzzaman, Kazi Firoz Ahmed, A.Z.M. Shahriar Muttalib, “A low cost surface electromyogram signal guided automated wheel chair for the disable”, International Journal of scientific & engineering research, Volume 3, Issue 2, February 2012. Mohan C, Vinod Kumar Giri, “DC motor control using EMG signal for prosthesis”, IJECT vol.2, Issue 2, June 2011. Jingpeng Wang, Liqiong Tang, John E Bronlund, “Surface EMG signal amplification and filtering”, International Journal of Computer Applications (09758887), volume 82- No.1, November 2013. Rubana H. Choudhury, Mamun B.I. Reaz, Mohd Alauddin Bin Mohd Ali, Ashrif A.A. Bakar, Kalaivani Chellappan, Tag G. Chang, “Surface electromyography signal [11] [12] [13] [14] [15] [16] [17] [18] [19] processing and classification techniques”, www.mdpi.com/journal/sensore, 17/september/2013. Muhammad Zahak Jamal, “Signal acquisition using surface EMG and circuit design consideration for robotic prosthesis”, http://dx.doi.org/10.5772/52556. Ignacio Rodriguez Carreno, Luis Gila Useros, Armando Malandra Trigueros, “Motor unit action potential deuration, measurement and significance”, http://dx.doi.org/10.5772/50265. Peter Konrad, “The ABC of EMG, A practical introduction to kinesiological electromyography ”, Version 1.4 March 2006. Mark Novak, Professor Cerin Sherman, “Design of am arm exoskeleton controlled by the EMG signals”, Cornel college PHY312, December 2011. Igor Liiz Bernardes de Moura, Luan Carlos de Sena Monteiro Ozelim, Fabiano Araujo Soares, “Low cost surface electromyographic signal amplifier based on arduino microcontroller”, International Journal of Electrical, Robotics, Electronics and Communications Engineering Vol:8 No:2, 2014. Carlo J. De Luca, “Surface Electromyography: Detection and Recording”, DYLSYS. http://en.wikipedia.org/wiki/Electroencephal ography http://en.wikipedia.org/wiki/Electrocardiogr aphy http://en.wikipedia.org/wiki/Commonmode_rejection_ratio Saravanan N, Mehboob Kazi M.S., “Biosignal based human machine interface for robotic arm”. Allada Triupathi Rao, M. Gopi, M.V.S.S. Prasad, “Real time ECg signal Transmission for remote monitoring”. ISSN: 2321-9939 http://en.wikipedia.org/wiki/Differential_am plifier 36 ELK Asia Pacific Journals – Special Issue 7. SUSTAINABLE APPLICATION OF COMPOUND PARABOLIC SOLAR CONCENTRATOR D.K.Patel Mechanical engineering department, Government engineering college, patan Rai University, Ahmadabad, India e-mail -
[email protected] P.K. Brahmbhatt Mechanical engineering department, Government engineering college, modasa Rai University, Ahmadabad, India e-mail-
[email protected] Abstract—This paper will evaluate the sustainability of compound parabolic solar concentrator and their practical use in heating air and water in developing countries like India. Delivering sustainable energy will require an increased efficiency of the generation process including the demand side. The utilization of Solar Energy could cover a significant part of the energy demand in the country. A comprehensive review of the different Profile designs with Auto LISP developed for construction of Compound Parabolic Concentrator (CPC) having a flat one-sided absorber which does not require any tilt adjustment , details of construction of the wide diversity of practically designs of CPC systems is presented. Profile generated in Auto LISP is used for ray-tracing, modeling of multiple channelled concentrators and to gauge the distribution of the absorbed solar radiation on the absorber surface and the result can compared with a theoretical optical model based on the average number of reflections. A low cost solar air and water heater with CPC having an aperture area of 1.2m2 , an acceptance half angle of 30°and a flat absorber with concentration ratio two was fabricated and experimentally tested at Patan, North Gujarat (23.4ON, 72OE) and operating performances determined. The thermal performance of a compound parabolic Proc. Of the Int. Conf: ARIMPIE-2015 solar air and water heater for a single pass was investigated experimentally. The effect of mass flow rate of air on the outlet temperature, thermal efficiency was studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s-1 and water mass flow rate of 0.0025 kg s-1. The presented results can be considered important for the design and the operation of solar air and water heater used for drying agricultural products, space heating and, industrial purposes and solar water heater. The typical examples of CPC solar thermal applications are in cooking, water heating, air heating, drying of agricultural, space heating and ,industrial purposes and food products, water distillation, industrial process heating systems and power generation. Keywords— sustainability, solar concentrators, reflectors, solar air heater, compound parabolic concentrator,Autolisp I. INTRODUCTION As defined by the World Bank, sustainability is the ‘Development that meets the needs of the present without compromising the ability of future generations to meet their own needs’. Energy tends to be the main player in achieving the sustainable development based on the dramatic increase in the world energy consumption over the last few decades accompanied with the established relation between the recent technological advancement and energy consumption patterns. Moreover, attaining a sustainable and secure energy sector is the main challenge nowadays to achieve sustainability on the environmental, social and economic levels [1] various programs were launched by governments, academic, institutions and industrial sectors to develop new energy technologies, improve energy efficiency methods and strive to find alternative and clean energy resources. Energy is central to sustainable development and poverty reduction efforts. It affects all aspects of developmentsocial, economic, and environmental-including livelihoods, access to water, agricultural productivity, health, population levels, education, and gender related issues. Traditional method of energy production continues to degrade the ecosystem. Especially with some 37 ELK Asia Pacific Journals – Special Issue types of soil, land can be over-harvested until it is rendered useless. To encourage sustainability, an increasing number of programs are being implemented to expand the use of alternative fuels and energy. Renewable energy resources can improve quality of life by promoting sustainable development. Systems such as solar power are “practical, reliable, cost-effective, and healthier for people and the environment. Amongst all renewable energy resources, the energy from sun is available almost everywhere except the polar reasons. In view of this, solar energy technologies have attracted significant attention of the researchers worldwide. India receives solar energy equivalent to more than 5,000 trillion kWh per year, which is far more than its total annual energy consumption. The typical examples of low temperature solar thermal applications are cooking, water heating, air heating, drying of agricultural & food products, distillation, greenhouse etc. while the industrial process heating, air-conditioning and power generation etc. are the examples of high temperature applications. II. LITERATURE REVIEW Using the sun to dry crops and grain is one of the oldest and most widely used applications of solar energy. The simplest and least expensive technique is to allow crops to dry naturally in the field, or to spread grain and fruit out in the sun after harvesting. The disadvantage of these methods is that the crops and grain are subject to damage by birds, rodents, wind, and rain, and contamination by windblown dust and dirt. More sophisticated solar dryers protect grain and fruit, reduce losses, dry faster and more uniformly, and produce a better quality product than open air methods [2]. A great deal of experimental work over the last few decades has already demonstrated that agricultural products can be satisfactorily dehydrated using solar energy. Various designs of small scale solar dryers having thermal energy storage have been developed in the recent past, mainly for drying agricultural food products [3]. Controlled drying is practiced mostly in industrial drying processes. Hot air for industrial drying is usually provided by burning fossil fuels, and large quantities of fuels are used worldwide for this purpose. High cost of fossil fuels gradual Proc. Of the Int. Conf: ARIMPIE-2015 depletion of its reserve and environmental impacts of their use have put severe constraints on their consumption [4]. Discussions have concentrated on improving the efficiency of CPC concentrators by introducing new materials and techniques for solar radiation collection and absorption with minimal optical and thermal losses [5]. Yan et al developed a dynamic model of solar parabolic trough collectors applied as direct steam generation systems. The model was solved by an explicit Euler’s method and considered different working conditions and thermal parameters. The simulated results were validated using two real test data on typical summer and winter days, and the steam generating process from unsaturated water to superheated steam was studied. The relationship between output steam features and solar radiation, inlet water temperature, mass flow rate, and collector area were evaluated [6].Odeh and Morrison developed a transient simulation model to analyze the performance of industrial water heating systems by using parabolic trough solar collectors. The system consisted of a parabolic trough collector with a glass cover, a back-up boiler, and a thermal storage tank. The high-accuracy model was applied to optimize the system operation during transient radiation periods [7]. Kim et al. researched the thermal performance of evacuated CPC solar collector with a cylindrical receiver and analyzed a numerical model based on the irradiation determined in each moment; they concluded that the numerical model could accurately estimate the performance of the solar collectors [8]. Tchinda and Ngos developed mathematical equations to study the thermal processes in a CPC collector with a flat one-side receiver with various dimensions. The results showed that for a given length, the efficiency increased as the flow rate increased, and the outlet temperature of the heat transfer fluid decreased with an increase of mass flow rate; the selective coating and the nature of the reflector material changed considerably the thermal performance of the CPC [9]. Pramuang and Exell developed a method to determine the performance parameters the optical efficiency, the heat loss coefficients, and the effective heat capacity of a truncated CPC applied to an air heater under non-steady conditions. The optical efficiency 38 ELK Asia Pacific Journals – Special Issue and the first order loss coefficient agreement were around 2% and 3%, respectively. They concluded that their method could be applied at any time of the year in variable tropical climates where a steady state method was not possible [10]. Prapas et al. investigated the flow distributions through the receiver tubes of a CPC collector for both east–west (E–W) and north– south (N–S) alignments of the system. The results showed that the flow distribution was non-uniform in an E–W alignment, compared with a close approximation to a uniform distribution for the N–S alignment. However, both alignments presented a similar thermal state performance of the concentrator[11]. Prasad and Tiwari developed a thermal analysis of a concentrator‐assisted solar distillation unit to optimize the glass cover inclination. The solar device was a CPC. An analytical expression for the air mass flow rate, wind speed and the collector length on the thermal performance of the air heater, an instantaneous thermal efficiency was carried[13]. This paper will evaluate the sustainability of compound parabolic solar concentrators and their practical use in heating air and water for cooking, water heating, air heating, drying of agricultural and food products, water distillation, industrial process heating systems and power generation in developing countries like India. III. COMPOUND PARABOLIC CONCENTRATOR (CPC) CPC is a non-imaging type concentrating solar collector where the incident rays, after reflection from the reflector, are not focused at a point or line but are simply collected on absorber (receiver) surface. The concentration ratio C, which is defined as the ratio of aperture area to absorber area is generally 2 to 10. CPC achieves the ideal concentration(C=1/sinθa). It is generally oriented in E-W direction. It does not need a continuous tracking of the sun but it necessitates only a few tilt adjustments per year. The rays incident in the range of acceptance angle 2 θa are fully accepted by CPC. The CPC, derives from the fact that it is consist of two parabolic mirror segments with different focal points. The angle between the axis of the CPC and the line connecting the focus of one of the parabolas with the opposite edge of the aperture Proc. Of the Int. Conf: ARIMPIE-2015 is the acceptance half angle θa. CPCs consist basically of three elements, (i) Receiver should have the highest absorptance for solar radiation as possible and must be constructed with high‐conductivity metals in order to conduct efficiently the absorbed heat into the heat transfer fluid. Most receiver materials do not have a very high absorptance, and they need to be covered with special solar selective surface coatings [1]. A commercial selective surface for applications in solar energy made from a silicon polymer, with an emissivity from 0.28 to 0.49 and absorptance values from 0.88 to 0.94 was applied on the surface of this receiver. (ii) Cover is a transparent insulation that allows the passage of solar radiation to the reflector and receiver, having a high transmittance of solar radiation, and a low transmittance of the thermal radiation from the receiver; also, it must have high durability and low cost. The cover used was a low-iron tempered glass with a thickness of 5 mm. (iii) Reflectors for solar concentrators should have the highest reflectance as possible. Its function is to focus beam‐solar radiation onto the receiver, which is located at the focus of the system. Two aluminum sheet segments with a reflectance of 0.87 were used to construct the reflector sides. IV. GEOMETRICAL CONSTRUCTION OF CPC PROFILE The acceptance angle of the CPC solar collector plays an important role in determining the optimal orientation of the collector and developing the most appropriate integrated tracking system. The aperture of the stationary CPC collector is always directed toward the equator at an angle equal to the local latitude and its axis is oriented either along the north– Geometric Profile of CPC (θa =30˚, L2=60) Fig. 1. 39 ELK Asia Pacific Journals – Special Issue south or the east–west direction depending on the specific application and the region of operation. CPC solar concentrators with larger acceptance angle are able to improve diffuse radiation interception, but this will yield a decrease in the concentration ratio of the collector. AutoCAD® offers lsp files which can be used for Auto LISP routings as acad.lsp. Auto LISP program is developed for geometrical profile generation of CPC from polar coordinate equations and file save as cpc.lsp. “Fig.1” shows CPC profile generated through Auto LISP CPC by adding two variables half acceptance angle and aperture length in loaded cpc.lsp file of AutoCAD®. V. MULTIPLE CHANNELLED CONCENTRATOR (MCC) MCC consists of a system of two or more channels, one inside the other, all of them having the same central axis. The walls of innermost channels have both the internal and external side reflecting. The wall of the external channel has only the internal side reflecting. The set of channels allows getting a less cumbersome concentrator in relation to the known concentrators, since the dimension of length is reduced. The MCC maintains the characteristics of an ideal concentrator, as it accepts all the radiations with an inclination smaller or equal to acceptance half-angle. Proc. Of the Int. Conf: ARIMPIE-2015 Multiple Channelled Concentrator CPC With length Surface (θa =30˚, L2=100,40,10) Fig. 3. The most important characteristics of these concentrators are less cumbersome, a large variety of choices in the planning, which allows a better adaption of the concentrator to the various types of usage, and the concentration of our proposed models, when used truncated, is larger than those of truncated Compound Parabolic Concentrators (CPC) for the same acceptance angle and the same length. Auto LISP program used to generate and modeling of multiple channelled concentrator consists of a system of two or more channels, one inside the other, all of them having the same central axis as per “ Fig.2(a)” model of three-channelled concentrator with acceptance half-angle θa=30˚,have all the characteristics of ideal concentrators, namely their concentration is C=1/sin 30˚=2 and they accept all the radiations with inclinations less than 30˚ rejecting those with inclinations greater than 30˚.The another model generated by Auto LISP as “ Fig.2(b)” three-channelled concentrator with various acceptance half-angle θa=30˚,25˚, 20˚and with same aperture length can be used the possibilities of bettering some of the known applications and of developing new projects. “ Fig.3” shows the mcc model with length in three dimensions.[13]. VI. ANALYSIS Multiple Channelled Concentrator (MCC) (a) CPC(θa =30˚, L2=100,40,10) And (b) (θa =30˚, 25˚,20˚,L2=100) Fig. 2. Applying heat balancing the following partial differential equations are be derived. For the transparent cover 𝑴𝒄 𝑪𝒄𝒑 𝝏𝑻𝒄 𝝏𝒕 = 𝒒𝒄 (𝒕) + 𝒉𝑹𝒑 (𝑻𝒑 − 𝑻𝒄 ) + 𝒉𝒑⁄𝒄 (𝑻𝒑 − 𝑻𝒄 ) − 𝒉𝑹𝒔 (𝑻𝒄 − 𝑻𝒔 ) − 𝒉𝒄⁄𝒂 (𝑻𝒄 − 𝑻𝒃 ) For the flat absorber 40 ELK Asia Pacific Journals – Special Issue 𝑴𝒑𝑪𝒑𝒑 𝝏𝑻𝒑 𝝏𝒕 = 𝒒𝒑 (𝒕) − 𝒉𝑹𝒑 (𝑻𝒑 − 𝑻𝒄 ) − 𝒉𝒑⁄𝒄 (𝑻𝒑 − 𝑻𝒄 ) − 𝒒𝒖(𝒕) For the fluid 𝒑𝒓𝒆𝒓 𝑪𝒑𝒇 𝝏𝑻𝒇 𝝏𝒕 = 𝒒𝒖 (𝒕) − 𝒎̇𝑪𝒑𝒇 𝝏𝑻𝒇 𝒍𝒑 𝝏𝒙 − 𝑼𝒐(𝑻𝒇 − 𝑻𝒃 ) The characteristics of the cpc’s Parameter Symbol Acceptance half angle Cover absorptance Flat plat absorber absorptance Cover transmittance Cover emittance Flat plate absorber emittance Cover reflectance Reflector reflectance Flat plate absorber reflectance 𝜼𝒊𝒏𝒔𝒕 = 𝑸𝒖 𝑨𝒄𝑰(𝒕) Value 30° 0.2 0.95 0.89 0.85 0.91 0.05 0.86 0.15 Proc. Of the Int. Conf: ARIMPIE-2015 environmental factors and the design variables The effect of the environmental factors are external and may not be easily altered for improved performance, thus only design variables are left as the only ones that may be considered for optimal collector performance. Auto LISP generated profile of CPC with acceptance half-angle 30˚and aperture length 60cm for the full and truncated solar collector was printed to scale as printing templates and used in the construction of the reflector support and profile. The printed ‘CPC profile generated by Auto LISP’ design templates was then glued to the wooden supporting plates, which was precut with measuring dimensions of(30x60x80cm), for the full profile.The respective profiles were cut out using an saw and assembled in the laboratory. This technique gave an accurate profile and structure supports, and a rigid exo-skeleton framework supported the reflective panels of the collector. Anodized aluminium with a specular reflectance of approximately 87% Where the useful thermal power QU extracted from the CPC collector is calculated from the relationship 𝑸𝒖 = 𝑭𝑹 𝑨𝑻 {𝑺𝒑 − 𝑼𝑳 (𝑻𝒇𝒆 (𝟎, 𝒕) − 𝑻𝒃 (𝒕))} The effect of increasing collector length on the thermal performance is found. As collector length is increased the absorber average temperature hence outlet temperature is appreciably increased. However instantaneous efficiencies slightly decrease with the increase in length of the collector which presumably results from the greater heat looses to the surroundings.[14]-[15]. VII. FABRICATION METHODOLOGY D.K.Patel and P.K.Brahmbhatt designed and manufactured Compound parabolic solar concentrator for air and water collector[16]. The factors which affect the performance of a solar collector include the Picture to show the prototype of CPC Solar Air Collector. Fig. 4. is rolled as per Wooden templates profile for reflector .The collector assembly was placed in a location where there was access to sunlight and throughout the experiment, the collector was kept with its absorber aligned east-west with the tilt angle being the latitude of the place (23.4O) towards south so as to maximize useful solar energy. Air and water used as the heat transfer fluid. One collector panel with CPC truncated of the full size within the acceptance half angle of 30˚is fabricated. The collector has a total aperture area of 1.2 m2 and a flat plat absorber area of 0.48m2. This collector has overall dimensions of 0.8m height; 0.6m aperture width, 0.3m receiver width and 1.6m length the 41 ELK Asia Pacific Journals – Special Issue receiving surface which is black painted GI sheet absorber plate for improving the value of the heat transfer coefficient between the absorber plate and the fluid thus result in a higher efficiency and low cost material as shown in “ Fig.4” . VIII. EXPERIMENTAL METHODOLOGY a. Compound Parabolic Solar Air Collector The performance test of the solar air collector prototype was carried out with glazing and thermal insulation including rectangular airflow duct, and total weather station at the Patan, North Gujarat (23.4ON, 72OE). In the experiment we measured the readings of global radiation Ht, absorber temperature Tr, reflector temperature Tm, cover temperature Tb, air inlet temperature Tin, air outlet temperature Tout and ambient temperature Ta, were taken for two mass flow rates m (0.012 kg/s and 0.016 kg/s) from 8 a.m. to 5p.m. at the interval of 1 hour in the month May. Flowrate=0.012Kg/s Ta Tin Tout 70 Proc. Of the Int. Conf: ARIMPIE-2015 Temperature versus different standard local time during days for the air mass flow rate at 0.016 Kg/s corresponding to the outlet, inlet, and ambient. Fig. 6. In this study the absorber was made of galvanized iron sheet with black chrome selective coating and thickness of plate was 0.5mm. “ Fig.5&6” show the variation of the ambient, outlet and inlet temperatures as a function of air mass flow rates and time during day. The temperature was measured experimentally, and it can be seen from graph that the curves of outlet temperature tend to decrease with increasing air mass flow rate. For a specific air mass flow rate at a constant ambient temperature, the outlet and inlet temperatures increase with increasing solar intensity. In general, the inlet temperature was found to be increasing exponentially from the morning for mass flow rates m =0.012 kg/s and 0.016 kg/s. Drying under controlled conditions of temperature and humidity helps the agricultural food products to dry reasonably rapidly to safe moisture content and to ensure a superior quality of the product. 60 b. Compound Parabolic Water Collector 0 Temperature (C ) 50 40 Solar 30 20 10 Tb Tr To 0 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 80 Time (Hr) 70 50 0 Temperature( C) 60 . Temperature versus different standard local time during days for the flow rate at 0.012 Kg/s corresponding to the outlet, inlet, and ambient. Fig. 5. 40 30 20 10 Flowrate=0.016 Kg/s 70 0 Ta Tin Tout 8 9 10 11 12 13 14 15 16 17 18 Local Time (Hr) 60 0 Temperature (C ) 50 40 Absorber ,Water Outlet and Ambient temperature during day time for the water mass flow rate at 0.0025kg/s Fig. 7. 30 20 10 0 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 Time (Hr) Using the CPC profile generated by Auto LISP program with acceptance half-angle 30˚and 42 ELK Asia Pacific Journals – Special Issue aperture width 60cm and 160cm length , a wooden mould was prepared . The collector assembly was placed in a location where there was access to sunlight and throughout the experiment, the collector was kept with its absorber aligned east-west with the tilt angle being the latitude of the place (23.4O) towards south so as to maximize useful solar energy. Water was used as the heat transfer fluid. The performance test of the prototype was carried out without glazing and thermal insulation including reflector, absorber and storage tank and total weather station at the Patan, North Gujarat (23.4ON, 72OE). In the experiment we measured the readings of global radiation Ht, absorber temperature Tr, reflector temperature Tm, cover temperature Ta, water inlet temperature Ti, water outlet temperature To and ambient temperature Tb, was taken for one mass flow rate m (0.0025 kg/s ) from 8 a.m. to 5p.m. at the interval of 1 hour in the month February. IX. CPC’S ACHIEVE SUSTAINABILITY Highlighting the sustainable aspects of the compound parabolic collector is a simple task because the device is sustainable by nature. It has been created with the intent of helping those who lack clean drinking water, with the focus being to improve their quality of life and drying process in the preservation of agricultural products, food products, especially fruits and vegetables require hot air in the temperature range of 45–60°C for safe drying. Developing efficient and cost effective CPCAH solar dryer with thermal energy storage system for continuous drying of agricultural food products at steady state and moderate temperature (40– 75°C) has become potentially a viable substitute for fossil fuel in much of the developing world like India. The hope is that one day, solar parabolic collectors will provide a continuous source of air heating and hot potable water, and people will never go without the basic need. By implementing the simple technology, several positive outcomes will occur that benefit the people who will use them in a sustainable way over the long term thus hot air for industrial drying, agricultural products and foodstuff, such Proc. Of the Int. Conf: ARIMPIE-2015 as fruits, vegetables, aromatic herbs, wood, and hot water are usually provided by burning fossil fuels, and large quantities of fuels, high cost of fossil fuels gradual depletion of its reserve and environmental impacts of their consumption are saved worldwide for these purpose. CPC profile generated by Auto LISP is more accurate, error free and requires less time than drawn by hand, used for modeling of mcc and analyzing raytrace for different incident angle. The MCC generated have the better advantages in fact under the same length of truncation a greater concentration than the CPC. In particularly MCC may be used for photovoltaic cell, as to obtain as much as possible uniform density of concentration on it. CPC prototypes are based around providing the most efficient design, easily geometrically constructed and fabricated through using low cost material(GI) factoring in cost and durability, amongst other features .The water outlet temperature (76˚C) attained by CPC is higher than available in FPC even when the CPC is flat. The efficiency of the Solar Air collector improves with increasing solar intensity at mass flow rate of 0.012 and 0.016 kg s-1, due to enhanced heat transfer to the air flow. Optimum values of air mass flow rates are suggested to maximize the performance of the solar collector. The reason for the significant increase in efficiency from of 0.012 and 0.016 kg s-1 can be attributed to changes in flow condition from laminar to turbulent. It could also be seen that slope of the efficiency curves decreases, meaning decrease in loss coefficient, with increase in mass flow rates. The air outlet temperature (66˚C) attained by CPC is higher than available in FPC even when the CPC is flat. The stationary low cost CPC solar air heater and water heater with the concentration ratio of 2 suns has been proposed for air heating with specific advantages of no need of continuous tracking, no utmost accuracy required in fabrication, acceptance of diffuse radiation, saving of material by truncation, low loss and used for domestic up to small commercial size drying of crops, agricultural products and foodstuff, such as fruits, vegetables, aromatic herbs, wood, etc., contributing thus significantly to the economy of small agricultural communities and farms. Thus compound solar 43 ELK Asia Pacific Journals – Special Issue parabolic collector qualified as a sustainable technology and has to improve the quality of life for a community or species, and retain those improvements indefinitely for Sustainability. Reference [1] [2] [3] [4] [5] [6] [7] [8] [9] Chen CF, Lin CH, Jan HT, et al. Design of a solar concentrator combining paraboloidal and hyperbolic mirrors using ray tracing method. Opt Commun 2009;282:360–6. L. M. Bal, S. Satya and S. N. Naik, “Solar dryer with thermal energy storage systems for drying agricultural food products: A review”, Renewable and Sustainable Energy Reviews, vol. 14, (2010), pp. 2298-2314 . A. Madhlopa and G. Ngwalo, “Solar dryer with thermal storage and biomass-backup heater”, Solar Energy, vol. 81, (2007), pp. 449-62 V. Shanmugam and E. Natarajan, “Experimental study of regenerative desiccant integrated solar dryer with and without reflective mirror”, Applied Thermal Engineering, vol. 27, (2007), pp. 1543-51. Grass C, Schoelkopf W, Staudacher L, et al. Comparison of the optics of non-tracking and novel types of tracking solar thermal collectors for process heat applications up to 3008C. Sol Energy 2004;76:207–15. Yan Q, Hu E, Yang Y, Zhai R. Dynamic modeling and simulation of a solar direct steam generating systemInternational Journal of Energy Research 2010;34:1341– 1355. Odeh S. D, Morrison GL. Optimization of parabolic trough solar collector system. International Journal of Energy Research 2006; 30:259 –271. Kim Y, Han G, Seo T. An evaluation on thermal performance of CPC solar collector. International Communications in Heat and Mass Transfer 2008; 35:446 – 457. Tchinda R, Ngos N. A theoretical evaluation of the thermal performance of CPC with flat one-sided absorber. International Communications in Heat and Mass Transfer 2006; 33:709–718. Proc. Of the Int. Conf: ARIMPIE-2015 [10] [11] [12] [13] [14] [15] [16] [17] [18] Pramuang S, Exell THB. Transient test of a solar air heater with a compound parabolic concentrator. Renewable Energy 2005; 30:715–728. Prapas DE, Norton B, Melidis PE, Probert SD. Convective heat transfers within air spaces of compound parabolic concentrating solar‐energy collectors. Applied Energy 1998; 28:123–135. Prasad B, Tiwari GN. Effect of glass cover inclination and parametric studies of concentrator-assisted solar distillation system. International Journal of Energy Research 1996; 20:495–505. D.K.Patel and P.K.Brahmbhatt (2014)’Compound Parabolic Solar Concentrator with AutoLISP’ Proc. Ist International Conference on MEET, Bhopal. pp 941-947. Rene T chinda .Thermal behavior of solar air heater with compound parabolic concentrator. Energy conversion and Management 49(2008) 529-540. Science Direct, Elsevier. D.K.Patel and P.K.Brahmbhatt , Analysis and Performance Investigations on a Solar Air Heater with Compound Parabolic Concentrator International Journal on Recent and Innovation Trends in Computing and Communication , Volume: 3 Issue: 2,(2015) Page 064-071. D.K.Patel and P.K.Brahmbhatt (2014)’Computer Aided Design and Manufacture Of Compound Parabolic Solar Air Collector’’ Proc. International Conference on Recent Trends in Engineering and Technology, Published by Elsevier, pp, 134-136 Duffie JA, Beckman WA. Solar engineering of thermal process New York: John Wiley and Sons; 1980. Patel DK, Brahmbhatt PK. Thermal performance of compound parabolic solar air heater. Discovery, 2015, 29(112), 138143. 44 ELK Asia Pacific Journals – Special Issue 8. EFFECT OF RADIATIVE HEAT TRANSFER TERM IN WEAK NON–LINEAR WAVES IN FLUID WITH INTERNAL STATE VARIABLES Nahid Fatima Amity Valley, Pachgaon, Gurgaon, Haryana
[email protected] Abstract: In present paper, an attempt has been made to discuss the effect of radiative heat transfer term in weak–non–linear waves in fluid with several internal state variables. . The analytical method of characteristics is used to show that a plane finite amplitude disturbance propagates through this system at the frozen sound speed. Behaviour of finite amplitude gas dynamic disturbance headed by a planer, cylindrical or spherical wave front in characteristic plane is investigated. Key Words: Radiative Heat Transfer Non Linear Waves, Fluid I. INTRODUCTION Proc. Of the Int. Conf: ARIMPIE-2015 Studies of non–linear wave by using the progressive–wave theory have been carried out by several authors. Germain9 reviewed the theory of progressive waves for wide applications in several fields. Fusco and Engelbreckt8 presented the asymptotic analysis of non–linear waves in rate dependent media to study the high and low frequency wave processes and obtained an evolution equation for visco–elastic media. Shukla et.al.13 have applied progressive wave approach to study decay behaviopur of a saw–tooth profile in chemically–reacting gases. Clark and Rodgers6 have investigated the structure of plane steady shock–wave in a gas with several internal energy modes. Becker and Böhme1 have discussed the structure of compression wave for n–parallel relaxation modes. Colemann and Gurtin7 have discussed the growth and decay of discontinuities in fluids with internal state variables. Equations governing one dimensional motion of a fluid with several internal state variables, neglecting various transport effects, are given by ,t + u,x + u,x + Certain papers,2,3,4,5,7 deal with the analysis of formation of plane shock waves in one dimensional unsteady flow with discontinuities resulting from the motion of a piston. Clark5 has discussed growth and decay behaviour of plane waves propagating through a spatially uniform but time dependent chemically reacting gas mixture in a general state of disequilibrium. Sharma and Shyam12 have discussed behaviour at the wave head of a finite amplitude gas dynamic disturbance in a chemically reacting fluid. Pandey and Chaturvedi11 have discussed weak waves in reacting gases. Ojha and Tiwari10 have considered propagation of spherical shock– waves in non–ideal atmosphere. In many important phenomenon, it is necessary to investigate the processes, in which there occurs the motion of the mixture or various gases and fluids, or gases and fluids with solid particles, or fluids only, accompanied by chemical phase or some other transition and the phenomena of diffusion, representing itself the internal relative motion of substances constituting the mixture. u 0 x (1.1) u,t + uu,x + p,x = 0 (1.2) (1.3) ci,t + uci,x = wi , (i 1,..., N ). (1.4) where t is time, x is the distance of the axis or the centre of symmetry from a plane , ‘’ is the density, p is the pressure, ‘u’ is the gas velocity, ‘ci’ concentration of the ith species and wi rate of production of ith species respectively. af is the frozen sound speed given by a f2 (p, ) S,ci h, 1 h, p (1.5) where subscripts S,ci denote that the derivative is taken with these quantities held constant, while S is entropy and h being enthalpy given by h = h(p, S,c1,c2,...cn) Thus, 45 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 h h, p ,ci (2.4) h h, p p ,ci af [(ci),t, + (ci),t,] = and = 0, 1, 2 refers to the case of a planer cylindrical and spherical motion respectively and comma followed by an index denote partial differentiation with respect to that index. II. EQUATIONS FORM IN wiJ (2.5) Adding and subtracting equation (2.3) and (2.4), we have CHARACTERISTIC (2.6) and Following Wegener14, we choose axis of symmetry in the direction of propagation of wave and introduce two characteristic variables and defined as follows : dx x, u a f , where (x, t) constant dt t , and dy x, u a f , where (y, t) constant dt t , Applying transformation and x, ( f ), x, ( f ), f, t J (2.1) t , ( f ), t , ( f ), f, x J where J x, x, t , t, 0, equations (1.1) to (1.4) reduces to af(,t, + ,t, ) + (u,t, – u,t, ) + u J 0 r (2.2) af (u,t, + u,t, ) + (p,t, – p,t, ) = 0, (2.3) (p,t, + p,t, ) + ρaf (u,t, – u,t, ) (2.0a) (2.0b) (2.7) If unperturbed field ahead of the wave whose behaviour is to be investigated is assumed to be spatially uniform, all x derivatives of equations (1.1) to (1.4) vanishes and thus, we have 0,t = 0 i.e. (2.8) 0 = constant, 0u0,t = 0 i.e.u0 = 0, (2.9) (2.10) w c i 0,t i 0 (2.11) i = (1, 2, ..., n). where subscript 0 indicates a value in the background field. From equation (2.8) to (2.11) the background state can be visualized in terms of a fixed vessel uniformly filled with the gas mixture which is at rest. Perturbations of the background state will be assumed to propagate through the mixture behind the wave–front = 0 46 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 . Continuity of the variable p,,u and ci (i = 1,...N) at = 0 is essential but discontinuities in their derivatives are permitted. Any derivatives with respect to must be continuous, discontinuities can appear only in the derivatives. III. BEHAVIOUR AT THE WAVE–FRONT Differentiating equation (2.6) with respect to ‘’ and equation (2.7) with respect to ‘’ and subtracting one from the other and evaluating the resulting equation at = 0+, we get 2 0 a f 0 u, a f 0 [u, 0, , u 0, ] 0 a 2f 0 x Integrating equation , 0i a f0 i u , u , i 0 a f 0 (3.5), 1/ 2 we have t 1 a f0 exp 1 x ti 2 dt , (3.6) u, u, i is the value of at the initial where time t = ti. From equation (2.6) and equation (2.7), after some manipulation, we have p, t, p, t, a f (u, t, u, t, ) 2Q(Γ-1) [u, t 0, ] (3.7) From equation (2.0a) &(2.0b) when evaluated at = 0+ yields 2a f0 (t, ) u, t 0, (a f , t 0, a f0 , t, ) 0 (3.8) (3.1) Applying initial conditions given by (2.8) and (2.9) and = 0+ equations (2.2) to (2.5) reduces to a f0 , 0 u, (3.2) t 0, p, p 0, t, 0 a f0 t 0, u, (3.3) t 0, c i , t, c i 0, 0, (3.4) From the above equation, we get 1 u, t 0, (t , ), 4 a f0 (3.9) Combining equation (3.1) with (3.2) to (3.4), we get Equation (3.9) can be written as 1 u , t 0 , ( t , ), 2 t 0 , t , 0 4 a f0 a f0 1 log[( 0 a f0 )1/ 2 u, ] 1 t0, 2 x where (3.5) where Integrating equation (3.10), we have (3.10) t t, t,i exp 2 ( t )dt ti 47 ELK Asia Pacific Journals – Special Issue t u , i e 1 0 a f0 i t 4a f 0a f 0 0 i 2 ( t ) dt t ti t t ei 1/ 2 1 a f 0 2 x dt Proc. Of the Int. Conf: ARIMPIE-2015 .dt (3.11) where = 1 + 2 and t = ti. u, r u, ri u i is value of u at 1/ 2 0i a 3f0 i 0 a 3f 0 t a f0 u, i exp 1 (t ) dt x ti 2 t a f 1/ 2 3 (t ) x 0 dt t a 1 0i f0 i ti 1 ( 1)u, i .e .dt 0 a 3f 2 ti 0 (3.12) IV. DISCUSSION for 0 2 | | /( 1) 1/ 2 exp( | | R0 / a f 0 ) | | a f 0 (u, x ) C 2 1 ( 1)erfc (| | R / a )1 / 2 R 0 0 f0 2a f 0 exp( | | R0 / a f 0 ) for 2 ( 1) R0 Ei (| | R0 / a f 0 ) then u, x 0 as t , the wave damps out ultimately. But if u, x < 0 and | u, x | > ( u, x )C then there exists finite time ts given by 1 2 | | ts log 1 | | | u, x | ( 1) i 1 for 0 For a plane wave = 0, equation reduces to the form as obtained by Clarke25, and, therefore, all his conclusions follow immediately. and Here, we shall consider the following situations in which the wave–front is of cylindrical or spherical geometry. such that | u, x | as t ts, i.e. the wave Case I: If the medium ahead is one of uniform equilibrium, in that case wi = 0 as a result of which p0, a f 0 etc. are constants and < 0. R(t) = R0 + a f 0 t , where R0 is the position of the wave front at time t = 0. Here ti has been set equal to zero for convenience. Thus, equation (3.12) reduces to u, x u, x ( R0 / R)/ 2 exp( | | t ) i 1 /2 1 u, xi ( R0 / R) exp( | | t )dt 2 0 t (4.1) ts (R 0 / R)/ 2 exp( | | t )dt 2 | u, x | ( 1) for 1,2 i 0 terminates into a shock at an instant ts. Thus, we find that a compression wave steepens up into a shock after a finite time only if the initial discontinuity associated with the wave is sufficiently strong. From the above expressions of ( u , r )C, we can see that (u, x ) C || 0 which means that the chemical reactions in the flow have a effect on the tendency of the wave surface to grow into a shock in the sense that an increase in || will cause ( u , r )C to increase and thus delays (u, x ) C R0 the shock formation. Also, 0 implies that the curvature has a stabilizing effect and that an increase in the initial curvature causes an increase in ( u , r )C. For | u, x | = ( u, x )C, it follows from (4.1) that at a plane compression wave head the discontinuity propagates with the constant initial strength and at a cylindrical and spherical wave head they propagate according to 48 ELK Asia Pacific Journals – Special Issue u, r 2 | | a f0 ( 1) R 1/ 2 Proc. Of the Int. Conf: ARIMPIE-2015 exp( | | R / a f0 ) erfc (| | R / a f0 )1/ 2 (4.2) and u, x mean that the chemical rate process in the flow accelerates the steepening of a compression wave to grow into shock. Reference 2a f 0 exp( | | R) (4.3) ( 1) REi (| | R) [1] respectively. Case II: [2] If the medium ahead is in a state of disequilibrium, i.e. w0 0 [3] (3.12) can be written in the following form u, x u, x ( R0 / R0 a f 0 t )/ 2 exp( t ) [4] [5] i t 1 / 2 1 u, xi R0 /( R0 a f 0 tˆ) exp(| | tˆ)dtˆ 2 0 (4.4) and indicate suitable mean value over the interval ti to t and ti has been equal to zero for convenience. From equation (4.4), if u, x < 0 and > 0, a [6] [7] [8] finite time t*s is given by [9] 1 2 t log 1 | u, x | 1 | i [10] for 0 * s [11] (4.5) [12] and t*s R0 2 exp( (t ))dt for 1,2 / 2 a t ) | u , | ( 1) 0 f0 x (R 0 i (4.6) Thus, we find that in a state of disequilibrium sufficiently far from equilibrium the discontinuity associated with a compression wave, no matter how small always breakup into a shock after a finite time. It follows from (4.5) and (4.6) that t *s 0 and t *s 0, R 0 [13] [14] [15] [16] Becker, E. And Böhme, G.: 1969, Non Equilibrium Flow (Part–I), Ed. By P.P. Wegener, Marcel Dekker, New York, P. 71. Becker, E. : 1970, J. Royal Aeronout. Soc., Vol. 74, P. 736. Bhutani, O.P. And Chandran, P.:1977,Int. J. Engng. Sci., Vol.15, P.537 Bürger, W.: 1966, Z.A.M.M., Vol. 46, P. 149. Chu, B.T.: 1958, Proc. Heat Transfer And Fluid Mech. Inst., Stanford University Press. Clarke, J.F.: 1977, J. Fluid Mech., Vol.81(No.2), P. 257. Clarke, J.F. And Rodgers, J.B.: 1965, J. Fluid Mech., Vol.21, P. 591. Coleman, B.D. And Gurtin, M.E.: 1967, The Phys. Of Fluids, Vol.10(No. 7), P. 1454. Fusco, D. And Engeklbreckt, J.: 1984, Nuovo Cim. Vol.80(B), P. 49. Germain, P.:1972, Progressive Wave Jber, DGLR, P. 11. Ojha And Tiwari: 2004, Ultra Scientist Phys. Sci., Vol.16(No.2), P. 205. Pandey, K. And Chaturvedi, R. : 2004, Proceeding National Academy Science, Vol. 74A(No.3), P. 285 Sharma, V.D. And Shyam, R.:1980, India J. Pure Appl. Math., Vol.11 (No.4), P. 478. Sharma,V.D.,Sharma,R.R.,Pandey, B.D. & Gupta, N.:1992,International Journal Of Eng. Science, Vol.30,P.263 Shukla, P., Sharma, R.R. And Singh, L.P.: 1994, Int.J.Engng Sci., Vol.32(No.3), P. 527. Wegener, P.: 1970, Non Equilibrium Flow, Part–II, M Arcel Dekker. 49 ELK Asia Pacific Journals – Special Issue 9. INVESTIGATION TO COMPARE HEAT AUGMENTATION FROM PLANE, DIMPLED AND PERFORATED DIMPLE RECTANGULAR FINS USING ANSYS Sachin Kumar Gupta Student, Thermal Engineering Gautam Buddha University Greater Noida, India
[email protected] Dr. Harishchandra Thakur Assistant Professor, Thermal Engineering Gautam Buddha University Greater Noida, India
[email protected] Abstract—The investigation is conducted to compare heat transfer rate from Plane, Dimpled and Perforated Dimple Rectangular Fins under natural convections. This numerical simulation is accomplished by 3D modeling and analysis using Solidworks and ANSYS, 14. This will help in finding out the new fin topologies with heat transfer characteristics that will do better than conventional plane fin.The main goal is to increase the heat transfer rate through the fin surface and to decrease material cost. The main techniques through which fins increase the Nusselt number are through Boundary layer regeneration and flow mixing enhancement. Dimpled and perforation are applied to smooth surfaces to promote flow mixing and initiate turbulence in the flow. Seven fins are designed in this research first finis plane fin, three are dimpled and another are perforated dimpled finwithdifferent shapes (circle, square and triangle). The different shape dimple on the fin have same cross section area of 100mm2and perforation done on different shape of dimple also having same cross section area of 64 mm2. These dimples and perforated dimples aredistributed on 2 rows and 3 columns. The results show that for same base temperature the perforated dimple fins having higher Proc. Of the Int. Conf: ARIMPIE-2015 temperature drop then the dimpled and plane fin. Triangular perforated dimpled fin gives best value of convective heat transfer coefficient, nusselt number, heat transfer than the other dimpled and perforated dimple fin. Keywords—dimpled fin, plane fin, perforated dimpled fin, natural convection, heat transfer, thermal boundary layer, passive technique I.INTRODUCTION Enhancement of heat transfer is one of important significance in various industrial applications. One of the methods of augmenting heat transfer is the use of fins or extended surfaces. The thermal systems designed and sized to generate, transmit and dissipate the appropriate amount of unwanted heat as per required demand [1]. The heat generation may lead to burning problems which lead to system failure of electric and electronic so to overcome this problem, efficient heat sink is necessary. Natural convection is one of the heat removing techniques from devices and plays an important role in maintaining their reliable operation. Extended surfaces (fins) are used in heat exchanging devices to increase the heat transfer between a primary surface and the surrounding fluid. Due to increasing in demand for lightweight, compact, and economical fins, the optimization of the fin size become significant. So the fins designed to achieve maximum heat removal with minimum use of material, and also simplicity in manufacturing of the fin shape. Various types of heat exchanger fins, ranging from relatively simple shapes, such as rectangular, square, cylindrical, annular, tapered or pin fins, to a combination of different geometries, have been used [2]. Passive techniques are used in solar heater, electronic cooling devices, biomedical equipment etc. The research on dimples or surface indentations are considered important because in dimple manufacture the material is removed whereas in pin-fin or rib tabulators extra material is added which leads to increase in weight and cost of the equipment. A variety of Numerical and experimental work has been carried out on augmentation of heat transfer. 50 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 II.CLASIFICATION OF ENHANCEMENT TECHNIQUES surface of the duct with bulk fluid from the core flow. Heat transfer enhancement or augmentation techniques refer to the improvement of thermo hydraulic performance of heat exchangers. Existing enhancement techniques can be broadly classified into three different categories: (v) Swirl flow devices: They produce and superimpose swirl flow or secondary recirculation on the axial flow in a channel. These include helical strip or cored screw type tube inserts, twisted tapes. They can be used for single phase and two-phase flows. 1. Passive Techniques 2. Active Techniques 3. Compound Techniques. The effectiveness of any of these methods is strongly dependent on the mode of heat transfer (single- phase free or forced convection, pool boiling, forced convection boiling or condensation, and convective mass transfer), and type and process application of the heat exchanger. Passive Techniques These techniques use surface or geometrical modificationssuch as perforation, protrusions, dimples and pin fins to the flow channel by adding inserts or additional devices. They alter the existing flow behavior (except for extended surfaces) which promotes higher heat transfer coefficients also increase pressure drop. Passive techniques do not require any direct input of external power rather use it from the system itself which leads to an increase in fluid pressure drop. Heat transfer augmentation by these techniques can be achieved by using:[3] (i) Treated Surfaces: Surface having a fine scale alters their finish or coating which may be continuous or discontinuous. They are used for Boiling and condensing duties. (ii) Rough surfaces: The surface modification which promote turbulence in the flow field. (iii) Extended surfaces: It provide effective heat transfer and modified finned surfaces also led to improve the heat transfer coefficients by disturbing the flow field in addition to increasing the surface area. (iv) Displaced enhancement devices: These are the inserts that are used primarily in confined forced convection, and they improve energy transport indirectly at the heat exchange surface by displacing the fluid from the heated or cooled (vi) Coiled tubes: These lead to relatively more compact heat exchangers. It produces secondary flows and vortices which promote higher heat transfer coefficients in single phase flows as well as in most regions of boiling. (vii) Surface tension devices: These consist of wicking or grooved surfaces, which direct and improve the flow of liquid to boiling surfaces and from condensing surfaces. (viii) Additives for liquids: These include the addition of solid particles, soluble trace additives and gas bubbles in single phase flows and trace additives which usually depress the surface tension of the liquid for boiling systems. (ix) Additives for gases: It include liquid droplets or solid particles which are introduced in single- phase gas flows either as dilute phase (gas-solid suspensions) or as dense phase (fluidized beds). Active Techniques These techniques are more complex from the application and design point of view as the method requires some external power input to cause the desired flow modification and to improve heat transfer rate. It have limited application as it require external power as it is difficult to provide external power input in many cases. Augmentation of heat transfer by this method can be achieved by [3]: (i) Mechanical Aids: Instrument stir the fluid by mechanical means or by rotating the surface which includes rotating tube heat exchangers and scrapped surface heat exchangers. (ii) Surface vibration: Applied in single phase flows to obtain higher heat transfer coefficients. (iii) Fluid vibration: Used in single phase flows and considered to be the most practical type of vibration enhancement technique. 51 ELK Asia Pacific Journals – Special Issue (iv) Electrostatic fields: The form of electric or magnetic fields or a combination of the two from dc or ac sources, which can be applied in heat exchange systems involving dielectric fluids. Depending on the application, it can also produce greater bulk mixing and induce forced convection or electromagnetic pumping to augment heat transfer (v) Injection: Technique is used in single phase flow and pertains to the method of injecting the same or a different fluid into the main bulk fluid either through a porous heat transfer interface or upstream of the heat transfer section. (vi) Suction: It involves either vapour removal through a porous heated surface in nucleate or film boiling, or fluid withdrawal through a porous heated surface in single-phase flow. (vii) Jet impingement: It involves the direction of heating or cooling fluid perpendicularly or obliquely to the heat transfer Compound Techniques A compound augmentation technique is the one in which more than one of the above mentioned techniques is used in combination for improving the thermo-hydraulic performance of a heat exchanger. III. LITERATURE REVIEW Various experimental, analytical and numerical researcheshavebeen carried out on enhancement of heat transfer through dimpled fin. The first person to suggest the use of dimple on plane surface for heat transfer augmentation was Kuethe [4] in 1971, as per him the dimples are expected to promote vortex generation which results in heat transfer augmentation.Experimental analysis performed by V.N Afnasyev [5] on surfaces shaped by systems of spherical cavities and they found that heat transfer was increased by 150% as compared to plane surface. Nikolai Kornev[6] examined vortex structure and heat transfer augmentation in turbulent flow over staggered dimple array in narrow channel using Large Eddy Simulation. Mahmood and Ligrani [7] carried out an experimental analysis on the influence of dimple aspect ratio, temperature ratio, Reynolds number, and flow structure in dimple channel. Z Wang [8] carried out Proc. Of the Int. Conf: ARIMPIE-2015 Numerical simulation of laminar channel flow over dimple surface and identified a symmetric 3D horseshoe vortex inside a single dimple.S.L.Borse and I.H Patel [9] performed an experimental study on the effect of dimples on heat transfer over flat surface under forced convection. They conclude use of dimples on surface which results in heat transfer augmentationwith lesser pressure drop and also heat transfer enhancement is more effective in staggered arrangement as compare to in line arrangement. Moon [10] investigated the channel height effect on heat transfer over the dimpled surfaces. Heat transfer coefficient and friction factorswereinvestigated in rectangular channels, which had dimples on one side of wall. IV.ANALYTICAL ANALYSIS Numerical studies were conducted to determine the heat transfer on the different aluminium fins for natural convection.Analytical study has been calculated on following assumptions: 1. The fin material is homogeneous and isotropic. 2. The heat transfer coefficient is uniform over the fin surface. 3. There are no heat sources within the fin itself. 4. There is no free convection or radiation heat transfer. V.DATA PROCESSING Thissteady state investigationcarried out under natural convection for a given base temperature of the fins and ambient airtemperatures. The investigationis used to determine the values of performance parameters. A) Grashofnumber B) Nusselt number C) Average heat transfer coefficient D) Rate of heat transfer 52 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 to know the effect of shape on heat transfer through dimpled fin and perforated dimpled fin. where, g = Acceleration due to gravity, 9.81 m/s2 L = Length of the Plate in meters = Kinematic Viscosity at film temp in m2/s. β = Coefficient of volumetric expansion in K-1 T = Temperature difference in K Pr =Prandtl number Kair= Thermal conductivity of air at film temperature in W/mºC Qa = Average heat transfer rate in Watts VI.CFD MODELING AND SIMULATION The model is designed in Solidworks and simulation performed in ANSYS 14.5. Workbench environment with ANSYS system of steady state thermal has the capability of solving the convective transport of energy and the thermal conduction in solids. In the any CFD simulation, the steps in performing fluid analysis are: 1) Modeling in Solidworks 2) Import the geometry in ANSYS steady state thermal 3) Generating mesh 4) Set up the analysis byproviding boundary conditions 5) Control and monitor the solver to achieve a solution 6) Visualize the results and create a report. Geometry Modeling Different fin geometries were designed using Solidworks software which is specifically designed and preparation of geometry for simulation. The fins having length of 100mm, height of 120mm and its thickness is 3mm as shown in fig 1. There are 6 newly designed finsin which 3 are dimpled as shown in fig 1 and another 3 are perforated dimpled as shown in fig 2 of square, circular, and triangular shape. The fin is modeled with adding same amount of material in various dimpled fins and same amount of material subtracted in various perforated dimpled fin. The base area of various shapes of dimple and perforation are kept same Circular dimpled Square dimpled Triangular dimpled Figure 9: Solid Fin and Dimpled fins(circular, square, triangular) Circular Perforated Square Perforated Triangular Perforated Figure 10: Different Perforated (circular, square, triangular) Dimple Fins TABLE 1: DIFFERENT DIMPLES DIMENSION Dimension, mm Thickness, mm Area, mm2 Square dimple A=10 Circular dimple D=11.28 Triangular dimple S=15.3 2 2 2 100 100 100 53 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 TABLE 2: DIFFERENT PERFORATION DIMENSION Perforatio n Dimensio n, mm Perforated Area, mm2 Square perforate d dimple Circular perforate d dimple a=8 d=9.028 Triangul ar perforate d dimple s=12.235 64 64 64 Create Mesh for the Geometry The standard Mesher in a Steady State Thermal which enables an automatic mesh generation using efficient mesh generation techniques, meshes were created with high contact sizing relevance (dense meshing near the dimple surface). The total number of elements and nodes are 2092 and 4539 respectively. Analysis Setup Under Steady State Thermal of the ANSYS Workbench, appropriatematerials Aluminum assigned to the created fin.Then we move to setup for applying boundary conditions to the fin. The temperature of base of fin is fixed at 100oC and natural convective heat transfer from other face of the fins. Visualizing the Results When the solver was terminated, the results were examined which is the post processing step. Temperature distributionand heat flux along the fin surface as well as parameters likeNusselt Number, heat transfer coefficient and changes in other parameters can also be predicted bycomputational analysis. Fig.3 and Fig.4 shows the temperature and heat flux contours over the convective surface area of the solid, dimpled and perforated dimpled fin respectively. It can beseen that the dimpled and perforated dimpled fin are pumping out the more heat from the base. The top ends of the fins are cooled faster. 54 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Figure 3: Temperature Contours Along fins 55 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 than the corresponding shape dimpled fins and perforated triangular dimpled fin having higher than the other fins. From figure 8, it has been found that the heat transfer rate ofperforated triangular dimpled fin have higher than the corresponding shape dimpled fins and perforated triangular dimpled fin having higher than the other fins. Perforation in Dimpled fin leads to enhances heat dissipation rates and at the same time decreases the expenditure of the fin material. Figure 4: Heat Flux Contours along fins 100 VII.RESULTS AND DISCUSSION The simulation investigates the perforation and dimple shape geometry effecton the convective heat transfer from the fins by Natural Convection. In this study a comparison is made between different shapes of dimpled and perforated dimpled fin.The comparison of different fin by using temperature distribution along the fin is one of the many ways. The result show that thehighest temperatures drop along the non-perforated fin. Perforated Dimple fins having higher temperature drop than the corresponding shape dimpled fin and the triangular perforated dimple fin have lowest temperature drop.Also, the difference between temperature ofthe base and tip of the fin play an important characteristic in the perception of the work of the fin, which can beused to compare this characteristics with other fins and through the same graphics as shown in Figure 5which says that the highest drop of temperature between the fin's base and it’s tip occur in thetriangular perforated dimpled fin. This happen because the triangle area destroyed the area of thermalboundary layer larger than the rest shapes because its width larger than rest shapes. From figure 6, it has been found that heat transfer coefficient for perforated dimpled fins are higher than their corresponding shape dimpled fin and solid fin having lowest value. It is also found that the heat transfer coefficient is highest for triangular perforated dimpled surface. From figure 7, it is found that the Nusselt number of perforated dimpled fin have higher 98 96 94 92 90 88 0 20 40 60 80 100 120 Solid Fin Circular Dimpled Fin Square Dimpled Fin Triangular Dimpled Fin Perforated Circular Dimpled Fin Perforated Square Dimpled Fin Perforated Triangular Dimpled Fin Figure 5: Temperature Distribution along the Height of Fin 56 ELK Asia Pacific Journals – Special Issue 5.5315 6 5 4 Proc. Of the Int. Conf: ARIMPIE-2015 3.557 3.964 4.094 4.81 4.5586 4.7081 3 2 1 0 10 9 8 7 6 5 4 3 2 1 0 9.432 8.354 6.287 6.976 7.196 7.916 8.121 Figure 6: Variation of Heat Transfer Coefficient with different Fins 30 25 19.635 20.3 20 17.638 27.4286 23.85122.60423.345 5 15 10 5 0 Figure 7:Variation of Nusselt Number with Different geometries Figure 8: Variation of Heat Transfer Rate with Different Fins VIII.CONCLUSION From the investigation the following conclusion were made: It is found that the temperature drop along the perforated dimple fins length is consistently higher than that for the non-perforated and dimpled fin.It is found that the heat transfer rate is more for different perforated dimplefin compare to plane and dimpled fin. It is also concluded that from various dimpled fins circular shape dimple have minimum heat transfer rate whereas triangular shape have highest value. It is also concluded that from various perforated dimple fins circular shape dimple have minimum heat transfer rate whereas triangular shape have highest value. It is found that the Nusselt number, heat transfer andheat transfer coefficient is maximum in case of triangularperforated dimple fin. Perforated Dimplefin leads to decreases the expenditure of the fin material. 57 ELK Asia Pacific Journals – Special Issue Acknowledgment We would like to be thankful to the Gautam Buddha University, Greater Noida. At the same time we could not forget the direct or indirect support of faculty and friends to make this paper successful. References [1] G. D.Gosavi , S.V.Prayagi and V.S.NarnawareG, “use of perforated as a Natural Convection Heat Transfer- Review,” International Journal of Current Engineering and Technology, special issue 2, pp. 506509, february, 2014. [2] Sahin B, Demir A (2008b). "Performance analysis of a heat exchanger having perforated square fins", Applied Thermal Engineering 28(6): 621-632. [3] Kakac E, Bergles A, Mayinger SF (1981). “Heat Exchangers, Thermal Hydraulic Fundamentals and Design” Hemisphere Publishing Corporation. [4] Kuethe A. M., (1971). “Boundary Layer Control of Flow Separation and Heat Exchange”, US. Patent No. 3,578,264. [5] V.N., Afanasyev, Ya.P., Chudnovsky, A.I., Leontiev, P.S.,Roganov, “Turbulent flow friction and heat transfer characteristics for spherical cavities on a flat plate”,Experimental Thermal and Fluid Science 7 (1) (1993) 1-8. [6] Nikolai Kornev. Flow structures and heat transfer on dimpled surfaces (http://www.tsfp7.org/papers/2B4P.pdf). [7] Mahmood, G. I., Ligrani, P. M., “Heat Transfer in a dimpled channel: combined influences of aspect ratio,temperatur6e ratio, Reynolds number and flow structure”, International Journal heat Mass Transfer 45, 2011-2020, 2002. [8] Z., Wang, K.Z., Yeo, B.C., Khoo, Numerical simulation of laminar channel flow over dimpled surface, AIAA Paper No. AIAA 2003-3964. [9] Dr.S.L.Borse and I.H. Patel,” Experimental investigation of heat transfer enhancement over the dimpled surface”, Iftikarahamad H. Patel et al. / International Journal of Engineering Science and Technology Proc. Of the Int. Conf: ARIMPIE-2015 [10] (IJEST) ISSN: 0975- 5462 Vol.4 No.8 August 2012 (PP no 3666-3672). Moon H.K., T. O’Connell, Glezer B., “Channel Height Effect on Heat Transfer and Friction in a Dimpled Passage”, ASME J. Gas Turbine and Power, 122, April 2000, Pp.307- 313. 58 ELK Asia Pacific Journals – Special Issue 10. DYNAMIC RESPONSE OF SELECTED FRUITS USING LASER DOPPLER VIBROMETER Jitendra Bhaskar1, Anand Kumar2, Bishakh Bhattacharya3 1,2 , Harcourt Butler Technological Institute, Kanpur, INDIA 3 Indian Institute of Technology, Kanpur, INDIA Email:
[email protected] Abstract-Mechanical damages make decay of fresh fruits fast during transportation from farms to packing houses and from packing houses to retail outlets. This damage could cause great economic loss to fruit industry. Fruits materials tend to behave as viscoelastic materials, when they are subjected to various conditions of stress and strain. Food can be regarded as a kind of complex polymer. The different food matrix shows different dynamic responses due to its nature of viscoelastic material. Dynamic response under pseudo-random excitation helps in predicting the behavior and selecting the material to protect the fruit. Laser Doppler vibrometer (LDV) is a very useful non-contact vibration measurement technique which gives us very good results. There are various types of fruits available in winter season of Northern India but some of them-Orange, Apple, and Pomegranate were selected for the dynamic response at SMSS lab IIT Kanpur. I. INTRODUCTION Mechanical injuries are responsible for considerable decay of fresh fruits and vegetables. Mechanical stresses occur during picking and packaging but a remarkable contribution to the development of damage can be due to transportation from farms to packing houses and from packing houses to retail outlets. With regard to transportation, frequent attention was devoted to delicate fruits such as apples. Singh and Xu (1993) reported that as many as 80% apples can be damaged during simulated transportation by truck depending on the type of truck, package and position of the container along the column. Other results of tests carried out on apples during transportation confirm high susceptibility of these fruits to mechanical Proc. Of the Int. Conf: ARIMPIE-2015 vibrations and the great influence of the kind of container on damage (Shulte et al., 1990; Timm et al., 1996). Apple fruit can be damaged because of some impact forces which are the main sources of apple degradation during the contact. To reduce the damage, it is necessary to investigate normal contact forces. The normal contact force models depend on dynamical parameters such as spring and damping. [1]. Vibration and shock during transport injures fruit and vegetables, especially fruit with a soft pericarp. Mechanical damage in truck transport, including abrasions and bruises, reduces quality to a level where truck transport may become problematic. Losses in fresh fruit rose by 17% and in vegetables 10% during transport and distribution in 2006 in Japan (Ministry of Agriculture, Forestry and Fisheries, 2008). Fruit must thus be packaged in cushioning sufficient to protect it from vibration and shock. Domestic fruit is mainly transported by truck using many types of containers, including corrugated fiberboard containers and cushioning materials. Fruit for export may also be packaged using the same material and design as in distribution in Japan, causing problems in mechanical damage and internal quality, necessitating the development of better packaging for exported fruit. Agricultural and food materials tend to behave as viscoelastic materials, when they are subjected to various conditions of stress and strain (Mohsenin 1986; Tsuji et al., 1992). Food can be regarded as a kind of complex polymer. The different food matrix shows different mechanical properties in different viscoelastic regions: the glass-like region, where the material shows a rigid and brittle character and the modulus is relatively high , the glass-transition region, where the storage modulus of the material decreases remarkably , the rubber-like region, where the material shows a high-elastic property; and the terminal region, where the material flows like liquid (Le Mast et al., 2002). II. LITERARTURE SURVEY: This study was conducted in Arabia to measure and analyze the dynamic response of fruit Apple under random force as natural excitation of road and truck condition to investigate the effect of 59 ELK Asia Pacific Journals – Special Issue vibration frequency 0-1.6 kHz and warping papers on the mechanical damage during transporting, the fruits were resting on foam bad to simulate free-free condition on the exciter with force transducer [2]. The physical, mechanical and chemical properties of banana fruits at different level of ripeness were determined in Iran. Relation between stage of banana ripeness and these properties were investigated and correlation coefficients were calculated [4].This research was conducted over one Iranian variety of Oak (Quercus Persica) with 70 observations. Physical and mechanical properties of oak were necessary for equipment used in activities such as transportation, storage, grading, packing etc. [5]. Fruits are usually graded according to their quality. Grading process was classifying fruits according to size, shape, weight, color and ripening stage [6]. In work done by Idriss ABOUDAOUD [7], objective was to study the feasibility of the control of the maturity of Orange fruit by the ultrasonic echo pulse method with immersion in water.In Tehran Maximum height for packing and storing of fresh pomegranate fruit in the box was determined to be less than 123 cm based on a rupture force of 40.7 N [8]. Effects of road conditions and packaging materials on all fig varieties were found statistically significant during transportation in Turkey. The cumulative effect of highway conditions (16 Hz∼2.54 m s-2) on the all visual attributes of the figs were five times higher than the off-road conditions (3 Hz∼0.56 m s-2). Highway road conditions severely affected the figs quality in all six visual attributes because of long transportation time. Although highway conditions have much smoother road conditions than off-road conditions, high acceleration created this visual harmful effect on the fresh fig fruits. According to the results of the experiment, transportation generally affected the quality of the figs in terms of visual and measured attributes. Highway conditions had more negative effects on the quality of the figs comparing to off-road conditions. This effect was accelerated because of the long transportation time of fruits. It was found that cardboard packaging materials are not convenient for transportation in any road conditions. Polystyrene boxes decreased the Proc. Of the Int. Conf: ARIMPIE-2015 negative effect of transportation comparing with the cardboard boxes [10]. III. MATERIALS: There are various types of fruits available in winter season of Northern India but some of them-Orange, Mosummi, Kinnu, Apple, Guava and Pomegranate were selected for the dynamic response. Fruits were purchased from local market near IIT Kanpur . IV. METHODOLOGY There are various types of methodologies used for getting dynamic response of objects. But non-contact types are very important in view of accuracy. Laser Doppler Vibrometer is very promising machine for measuring the dynamic response of objects. Figure 2: Orange on Figure 1 : Orange with shaker LDV V. RESULTS & DISCUSSIONS: Fruits were tested in winter season. This would be the reason of very slow weight loss due low evaporation rate. Orange, apple and pomegranate have very different nature of material inside the scalp. Orange was juicy, Apple was solid than orange. Pomegranate was having hard scalp than apple and orange. Structure and arrangement was pomegranate grains. Dynamic responses of steel bowl, Orange, Apple and Pomegranate were recorded on LDV with in 250, 500, 1000 & 2000 Hz range. Data plotted in frequency domain. All peaks showing maximum velocities at resonance. 60 ELK Asia Pacific Journals – Special Issue Graph 1: Only steel bowl 1000 hz 3200 fft Orange Graph 2: Dated-12/12/14 1-500Hz (wt 177.25 gm 19/12/14, 176.93 gm on 23.12.14) Graph 3: Dated-19/12/14 500 Hz Graph 4: Dated-23/12/14 (weight 176.93 gm) -500 Hz 800FFT Proc. Of the Int. Conf: ARIMPIE-2015 Graph 6: Dated-23/12/14 Graph 7: Jan 02, 2015 ( wt 157.65 gm) Pomegranate Graph 8: Dated-23/12/14 2000Hz Pomegranate Graph 9: Dated Jan 02, 2015 pomegranate Graph 5: Dated Jan 02, 2015 ( wt 176.32 gm) Apple 2000 Hz Dynamic response of only steel bowl has shown three peaks on approximate frequency 50 Hz, 410 Hz and 820 Hz. But when fruits were kept in bowl then third peak response on third frequency has been diminished. Graph 2 to 5 has shown almost same pattern only slighter change in the 5th. Orange has shown a similar dynamic response that first resonance frequency was observed at about 16-17 Hz. 61 ELK Asia Pacific Journals – Special Issue Table: showing the important data of graph. 1 reso. Freq Velocity 2nd freq. Remarks (Hz) Appr. data mm/s (Hz) Other peaks Hz 31.88 Hz 1.17 850 450 16-25 Hz 2.70-2.9 150-200 No change appreciable response between Dec.12-23, 2014 16-16.25 2.90 180-220 200, 640 Hz 16.88-17 3.16 300, 450, 800 Hz st Item Steel bowl Orange Pomegranate Apple Weight loss (gm) Dec 23 176.93 182.65 158.36 5. Apple and pomegranate have shown similar dynamic response that is first resonance frequency same as Orange, but other higher frequencies were also available at 650 Hz and 450 Hz. This may be due to solid/ non-juicy materials 6. inside. Fruits Orange Pomegranate Apple Proc. Of the Int. Conf: ARIMPIE-2015 Dec 19 177.25 - REFERENCES: 1. Evaluation of impact effect and fruit properties on apple dynamic behavior by Hossein Barikloo & Ibrahim Ahmadi, Australian Journal crop sciences AJCS 7(11):1661-1669 (2013) ISSN: 18352707. 2. Vibration analysis influence during crisis transport of the quality of fresh fruit on food security Ayman H. Amer E, Nabil S, Mostafa M. Azam CIGR Journal Open access at http://www.cigrjournal.org Vol. 15, No.3 181. 3. Post harvest chemical and physical– mechanical propertiesof some apricot varieties cultivated in Turkey Haydar Hacıseferog˘ullarıa,*,_Ibrahim Gezerb, Mehmet Musa O¨zcanc,Bayram Murat Asmada, Journal of Food Engineering 79 (2007) 364–373. 4. Comparison of Some Chromatic, Mechanical and Chemical Properties of Banana Fruit at Different Stages of Ripeness. Mahmoud Soltani Modern Applied Science Vol. 4, No. 7; July 2010. www.ccsenet.org/mas. 7. 8. 9. 10. Jan02, 2015 176.32 181.86 157.65 Physical and mechanical properties of Oak (Quercus Persica) fruits. Jalilian Tabar F. January, 2011 Agric Eng Int: CIGR Journal Open access at http://www.cigrjournal.org Vol. 13, No.4 1. Design and manufacturing of prototype for orange grading using phototransistor, Gamal Rashad Gamea*, Mohamed Aly Aboamera, and Maged Elsayed Ahmed Egypt. Australian Journal of Agriculture Engineering ISSN: 1836-9448. The maturity characterization of orange fruit by using high frequency ultrasonic echo pulse method Idriss ABOUDAOUD, Proceedings of the Acoustics 2012 Nantes Conference 2327 April 2012, Nantes, France. Determination of engineering properties of pomegranate fruit to calculation the height of box for handling ,Tehran, Iran. Hazbavi, International journal science invention today IJSIT, 2013, 2(6), 492501. Changes in the mechanical properties of the greenhouse tomato fruit skins DOI 10.2478/v10022-009-0001-z during storage in Lublin. TECHNICAL SCIENCES Abbrev.: Techn. Sc., No 12, Y 2009. Assessment of the Quality Losses of Fresh Fig Fruits during Transportation, Bülent ÇAKMAK, Journal of Agricultural Sciences, Turkey. October 2010. 62 ELK Asia Pacific Journals – Special Issue 11. EXPERIMENTAL STUDY OF COMPARISON OF SIMPLE VCRS AND VCRS WITH PHASE CHANGE MATERIAL(PCM) AS POTASSIUM CHLORIDE (KCL) Taliv Hussain1* ,Sahil Chadha2, Gaurav Singh Jaggi3,Rahul Wandra4,Gourav Roy5 Department of Mechanical Engineering, Lovely Professional University Phagwara, Punjab (India) -144402 Email:
[email protected] Phone no: 08283836492 Abstract-The performance of heat transfer is most essential area of research in the field of thermal engineering. For the process of heat transfer there are huge numbers of refrigerants which can be used to transfer the heat from low temperature reservoir to high temperature reservoir by using vapour compression refrigeration system. The vapour compression refrigeration technology has made a great improvement over a few decades in the form of efficiency of cycle through significant efforts of thermal engineers and manufacturers. The modification of cycle should be investigated to enhance the efficiency of the system. In this paper the experimental study is conducted to predict the comparison between the Simple VCRS and the VCRS with Phase change material (PCM) as KCL (potassium chloride) on the evaporator. In this paper the use of PCM can further decrease the temperature of the evaporator. We mainly bring the focus on to decrease the temperature of evaporator as lowest as possible so there is need of PCM. The use of PCM directly enhances the performance of the system by 21-25%.So by the use of the Phase change material there is an increment in the coefficient of performance (COP) of the system. Keywords: Phase change material, KCL, vapour compression refrigeration system,COP INTRODUCTION Vapour compression refrigeration system is a system which is used to transfer heat from low reservoir to the high reservoir by the use of a Proc. Of the Int. Conf: ARIMPIE-2015 working fluid known as a refrigerant. It is a system which uses the high grade energy results in the increase of coefficient of performance. Vapour compression refrigeration system which consists of certain parts such as Compressor, Evaporator, Condenser and Expansion valve. It has smaller size for the given capacity of refrigeration. This refrigeration system can be employed over a large range of temperatures and the coefficient of performance of this refrigeration system is quite high. To further increase the coefficient of performance the PCM (Phase change material) can be used in the evaporator and to get the lowest temperature of evaporator the PCM can also be used. It has the main advantage that it has the less running cost. In this refrigeration system the low pressure and temperature vapour refrigerant is drawn into the compressor through the inlet or suction valve where it is compressed to a high pressure and temperature. The high pressure and temperature vapour refrigerant is discharged into the condenser through the delivery or discharge valve. So this refrigeration uses the compressor work which is a high grade energy which implies that the amount of energy used in the system is totally converted into the useful work which helps to increase the coefficient of performance of this refrigeration system. LITERATURE REVIEW Webb (1984) developed a unified theoretical treatment of evaporative systems: cooling towers, evaporative coolers and evaporative condensers. His model considered the effect of the variation in temperature of the deluge water in an evaporative cooler, but stated that for an evaporative condenser the film temperature remains essentially constant due to the fact that the variation in the refrigerant temperature is negligibly small. Y.S.Lee and C.C.Su have studied the performance vapour compression refrigeration system with isobutene (R600a) as refrigerant and compare the results with R12 and R22. They used R600a about 150 g and set the refrigeration temperature about 4 °C and -10 °C to maintain the situation of cold storage and freezing applications. They used 0.7 mm internal diameter and 4 to 4.5 m length of capillary tube 63 ELK Asia Pacific Journals – Special Issue for cold storage applications and 0.6 mm internal diameter and 4.5 to 5 m length of capillary tube for freezing applications. They observed that the COP lies between 1.2 and 4.5 in cold storage applications and between 0.8 and 3.5 in freezing applications. A.S. Dalkilic and S. Wongwises [1], have studied the performance on a vapourcompression refrigeration system with refrigerant mixtures based on R134a, R152a, R32, R290, R1270, R600 and R600a was done for various ratios and their results are compared with R12, R22 and R134a as possible alternative replacements. The results showed that all of the alternative refrigerants investigated in the analysis have a slightly lower COP than R12, R22, and R134a for the condensation temperature of 50 °C and evaporating temperatures ranging between −30 °C and 10 °C. Refrigerant blends of R290/R600a (40/60 by wt. %) instead of R12 and R290/R1270 (20/80 by wt. %) instead of R22 are found to be replacement refrigerants among other alternatives. Yinhai Zhu and Peixue Jiang [4] developed a refrigeration system which combines a basic vapor compression refrigeration cycle with an ejector cooling cycle. The ejector cooling cycle is driven by the waste heat from the condenser in the vapor compression refrigeration cycle. The additional cooling capacity from the ejector cycle is directly input into the evaporator of the vapor compression refrigeration cycle the system analysis shows that this refrigeration system can effectively improve the COP by the ejector cycle with the refrigerant which has high compressor discharge temperature. Andrea Chesi, Giovanni Ferrara, Lorenzo Ferrari and Fabio Tarani [5] analyze a complex system in which the solar powered ejection machine is used to increase the efficiency of a traditional vapor compression machine by subtracting heat from the condenser. By means of a transient analysis, performed with a reference building and with climate data corresponding to four different system locations worldwide, the year-round performance of such a system in a space cooling application is Proc. Of the Int. Conf: ARIMPIE-2015 estimated in terms of energy balance and savings on power costs with respect to the traditional solutions. A. Selvaraju and A. Mani [6] investigate the experimental analysis of the performance of a vapor ejector refrigeration system. The system uses R134a as working fluid and has a rated cooling capacity of 0.5 kW. The influence of generator, evaporator and condenser temperatures on the system performance is studied. For a given ejector configuration, there exists an optimum temperature of primary vapor at a particular condenser and evaporating temperatures, which yields maximum entrainment ratio and COP. EXPERIMENTAL SETUP This experimental setup involves simple vapour compression refrigeration system with the basic parts such as evaporator, compressor, expansion device and condenser. This setup includes the reciprocating compressor and refrigerator R134a. In this system the phase change material (KCL) is also used in order to increase the coefficient of performance. In this particular setup air cooled condenser is used for the better heat transfer results. In this particular setup the PCM i.e KCL is used to enhance the performance and to obtain the better heat transfer rate. Fig:1 Experiment setup MEASURING DEVICES 1. Pressure Gauge: The bourdon pressure gauges are used to measure the suction (inlet) and discharge(outlet) pressure of compressor. 64 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 2. Thermocouple: Temperatures of refrigerant and the ambient air at different points are measured by use of RTD PT100 type thermocouples. and simple VCRS CALCULATION AND RESULTS Based on the experimental results, thermodynamic properties of the refrigerant at different points in the cycle are obtained using the P-H chart of refrigerant R-134a and the parameters such as mass flow rate, cooling capacity and COP of the system are calculated from the equations: 3. Voltmeter and Ammeter: Ammeter and voltmeter are used to measure the electrical current and voltage of input power respectively. Before temperature measurement, the surface of the tubes is polished for removing any type of dust or rust and then the thermocouples are laid onto the surface. Insulation tapes are wrapped around the copper tubes to prevent any heat losses to ambient air. A. Compressor Work Wc = V * I = mref* (h2 –h1) B. Mass flow rate of refrigerant mref OBSERVATION TABLE C. Cooling effect produced Qr = mref* Table 1: Result obtained by using PCM (Kcl) Parameters Unit and Symbol Simple VCRS system At (h1 –h4) VCRS with (Kcl) PCM At At At 30°C 27 °C 30 °C 27°C Suction Pressure Bar 0.24 0.55 0.43 0.51 Discharge Pressure Bar 9.72 9.49 11.16 10.43 Evaporator Outlet Temperature Degree Celsius(°C) 12.93 13.31 -17.1 -16 Compressor Outlet Temperature Degree Celsius(°C) 44.12 50.21 44 43.5 Condenser Outlet Temperature Degree Celsius(°C) 31.44 31.51 33.3 32.5 Current Ampere(A) 1.21 1.80 0.69 0.99 Voltage Volt(V) 190 190 190 190 D. COP = Where, h1 = enthalpy of refrigerant at inlet compressor in kj/kg (1) h2 = enthalpy of refrigerant at exit compressor in kj/kg (2) h3 = enthalpy of refrigerant at exit the condenser kj/kg (3) h4 = enthalpy of refrigerant at entry evaporator in kj/kg (4) of of of of Table 2: Result of the experiment at ambient air temperature 27°C Performance result of Air Conditioner (Tamb-27°C) Simple VCRS VCRS Parameter Unit system with (Kcl)PCM 229 131.1 3.75 4.74 Compressor Watt work Wc COP -----------65 ELK Asia Pacific Journals – Special Issue Table 3: Result of the experiment at ambient air temperature 30°C Proc. Of the Int. Conf: ARIMPIE-2015 [5]A. Selvaraju and A. Mani, “Experimental investigation on R134a vapor ejector refrigeration system”, International Journal of Refrigeration, Vol.29 (2006) pp.1160-1166. Performance result of Air Conditioner (Tamb-30°C) Simple VCRS VCRS Parameter Unit system with (Kcl) PCM Compressor work Wc Watt COP ------------ 342 188 3.87 4.53 REFERENCES [1] R.L. Webb, A unified theoretical treatment for thermal analysis of cooling towers, evaporative condensers, and fluid coolers, ASHRAE Trans 90 (Part 2B) (1984) 398–415. [2] Y.S. Lee, and C.C. Su, “Experimental studies of isobutene (R600a) as the refrigerant in domestic refrigeration system,” Applied Thermal Engineering 22, pp. 507–519, 2002. [3] A.S. Dalkilic, and S. Wongwises, “A performance comparison of vapour-compression refrigeration system usingvarious alternative refrigerants,International Communications in Heat and Mass Transfer, 37, pp. 1340–1349, 2010 [4] Yinhai Zhu and Peixue Jiang, “Hybrid vapor compression refrigeration system with an integrated ejector cooling cycle” International journal of refrigeration, vol.35, 2012, pp.68-78. [5] Andrea Chesi, Giovanni Ferrara, Lorenzo Ferrari and Fabio Tarani ” Suitability of coupling a solar powered ejection cycle with a vapour compression refrigerating machine” Applied Energy, vol.97, 2012, pp.374-383. 66 ELK Asia Pacific Journals – Special Issue 12. STUDY OF FATIGUE LIFE CALCULATION OF STEEL UNDER VARIOUS LOADING CONDITION Anil Kumar Asst.Prof (Krishna Engineering College)
[email protected] Abhishek Pandey Asso.Prof.(Krishna Engineering College)
[email protected] ABSTRACT- The aim of this work is to investigate the capability of experimental analysis, as a destructive tool testing, to characterize and quantify the fatigue behavior of material. This is achieved by studying the load parameter to the variations in material microstructure ,are the main factor affecting fatigue life .Family of steel including the mild steel,stainless steel are used in experiment and including the non-ferrous material as aluminum as a case of presenting the load and variation in microstructure both. Rotating bending test was performed on various standards fatigue specimen on rotating beam machine to correlate the parameter to the fatigue behavior .This enables the evaluation of the ability of fatigue tests to predict life of machine components. Keywords—Destructive tool, microstructure, rotating beam I. INTRODUCTION The Stress-Life Method To determine the strength of materials under action of fatigue loads, specimens are subjected to repeated or varying forces of specified magnitudes while the cycles or stress reversal are counted to destruction. The most widely used fatigue-testing device is the R. R. Moore high-speed rotating-beam machine. This machines subject the specimen to pure bending (no transverse sheer) by means of weights. The specimen is very carefully machined and polished, with a final polishing in an axial direction to avoid circumferential scratches. Other fatigue-testing machines are Proc. Of the Int. Conf: ARIMPIE-2015 available for applying fluctuating or reversed axial stresses, torsional stresses, or combined stresses to the test specimens[1]. To establish the fatigue strength of a material, quite a no. of tests are necessary because of the statistical nature of fatigue. For the rotatingbeam test, a constant bending load is applied, and the no. of revolution (stress reversals) of the beam required for failure is recorded. The first test is made at a stress that is somewhat under the ultimate strength of the material. The second test is made at stress that is less than that used in the first. This process is continued, and the results are plotted as an S-N Diagram. To establish the fatigue strength of a material, quite a no. of tests are necessary because of the statistical nature of fatigue. For the rotatingbeam test, a constant Bending load is applied, and the no. of revolution (stress reversals) of the beam required for failure is recorded. The first test is made at a stress that is somewhat under the ultimate strength of the material. The second test is made at stress that is less than that used in the first. This process is continued, and the results are plotted as an S-N Diagram. The chart may be plotted on semi-log paper or on log-log paper. In the case of ferrous materials and alloys, the graph becomes horizontal after the material has been stressed for a certain no. of cycles. The plotting on log paper emphasis the bend in the curve, which might not be apparent if the results were plotted by using Cartesian, coordinates. The ordinate of the S-N Diagram is called the fatigue strength Sf; statement of this strength value must always be accompanied by a statement of the no. of cycles N to which it corresponds. S-N Diagrams can be determining either for a test specimen or for a actual mechanical elements. Even when the material of test specimen and that of the mechanical element are identical, there will be significant difference between the diagrams for the two [2]. In the case of the steels, a knee occurs in the graph, and beyond this knee failure will not occur, no matter how great the no. of cycles. The strength corresponding to the knee is Called the 67 ELK Asia Pacific Journals – Special Issue endurance limit Se , or the fatigue limit. The graph never does become horizontal for nonferrous metals and alloys, and hence these materials do not have endurance limit. S-N curve for most common aluminium alloys excluding wrought alloys having a tensile strength below 38 kpsi. Since aluminium does not have an endurance limit, normally the fatigue strength Sf is reported at a specific no. of cycles N[1]. The body of knowledge available on fatigue failure from N=1 to N= 1000 cycles is generally classified as low-cycles fatigue or finite – life region. High-cycles fatigue is infinite-life region, and then is concerned with failure corresponding to stress cycles greater than 1000 cycles. Proc. Of the Int. Conf: ARIMPIE-2015 quenching fatigue life decreases while in case of annealing and normalizing fatigue life increases [7]. Experimental observation-1 Mild Steel Brine Quenched S.NO Stress (MN/sq.) No. Of Cycles 1 41.4 6389 2 31.05 14300 3 20.7 22000 45 Stress (MN/sq.m) As noted previously, it is always good engineering practice to conduct a testing program on the materials to be employed in design and manufacture. This, infect, is a requirement, not an option, in guarding against the possibility of a fatigue failure. Because of this necessity for testing, it would really be unnecessary for us to proceed any further in the study of fatigue failure except for one important reason, the desired to know why fatigue failure occurs so that most effective method or methods can be used to improve fatigue strength. Thus our primary purpose in studying fatigue is to understand why failures occur so that we can guard against them in an optimum manner. Experimental procedure-In this research we have done five experiment to analysing fatigue life. How fatigue life varies with Stress is shown in fig. Stress (MN/sq.m) 40 35 30 25 20 15 6000 9000 12000 15000 18000 21000 24000 No. of Cycles Experiment no-2 Mild Steel water Quenched S.NO Stress (MN/sq.) No. Of Cycles 1 41.4026 4448 2 31.05 12200 3 20.7 19998 We have taken five specimen such as mild Steel with various quenching method (oil, water and brine), aluminium and stainless steel to conduct experiment. Experiment conduct on rotating beam machine which was developed by R.R.Moore to know fatigue life is varies from load[4]. We have observed fatigue life decreases while increasing with load.in case of mild steel with 68 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 4 45 31.05 110 Stress (MN/sq.m) 40 35 Stress (MN/sq.m) 35 30 Stress (MN/sq.m) 30 25 Stress (MN/sq.m) 25 20 15 3000 6000 9000 12000 15000 18000 20 15 21000 No. of Cycles 10 Experiment no-3 oil quench 5 0 200 400 600 800 1000 1200 1400 No. of Cycles Mild Steel Oil Quenched Experiment no-5 S.NO Stress (MN/sq.) No. Of Cycles 1 41.4 9800 Stainless steel 2 31.05 17650 S.NO Stress (MN/sq.m) No. Of Cycles 3 20.7 25325 1 41.4 64878 2 51.75 11138 3 62.103 1274 45 Stress (MN/sq.m) 35 65 30 60 25 55 Stress (MN/sq.m) Stress (MN/sq.m) 40 20 15 6000 9000 12000 15000 18000 21000 24000 No. of Cycles Stress (MN/sq.m) 50 45 27000 40 35 Experiment no-4 0 10000 20000 30000 40000 50000 60000 70000 No. Of Cycles Aluminium CONCLUSION &DISCUSSIONStress S.NO (MN/sq.m) No. Of Cycles 1 11.3506 1180 2 12.93 908 3 20.7 304 By practical readings and further calculations it is investigated that heat treated specimen had low values of fatigue life, which is due to increase in brittleness, hardness and low endurance strength. Quenching invariably sets up residual stresses in the specimen and resulting in cracks. 69 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Generally the microstructure change takes place in the specimen which is also depicted in our experimental results. As above 725O C, the mild steel mainly contains face centered cubic structure known as Austenite. The solid solubility of Austenite is much higher than that of with solid solubility of up to 2.11 % C. Austenite is denser than ferrite and is ductile at elevated temperatures [6]. [6]. N. Damir, A. Elkhatib, G. Nassef “Prediction of fatigue life using model analysis for grey and ductile cast iron” International Journal of Fatigue vol.29 (2007) pg.499507(Elsevier). [7].Seakjee lee &young kook lee (2008); prediction of austenite grain growth during austenitization of low alloy steels material and design, vol29 pp1840-1844. When the specimen is suddenly cooled, the Austenite instantaneously starts transforming into Martensite as because the cooling curve does not enter into the pearlite region. Martensitic is very hard and higher percentage of carbon. [8].Ashwin Suresh Pandit, ―Theory of the Pearlite Transformation in Steels‖, (2011). The fatigue life of the specimen is reduced by increase in its brittleness and residual stresses. References[1]. V. B. Bhandari – Machine Design- Tata McGraw Hill Publications. [2]. Shigley-Machine Design- Tata McGraw Hill Publications. [3]. V. Kazymyrovych *, ‘’J. Bergström, F. Thuvander2010 Local stresses and material damping in very high cycle fatigue’’ International Journal of Fatigue,vol 32 (2010) pg.1669–1674(Elsevier).). [4]. Enrique Castillo,*, Alfonso FernandezCanteli c, Marı Luisa Ruiz-Ripoll ‘’ A general model for fatigue damage due to any stress history, International Journal of Fatigue vol30 (2008) pg.150–164(elsevier). [5]. G. Socha ‘’ Experimental investigations of fatigue cracks nucleation, growth and coalescence in structural steel’’ International Journal of Fatigue vol. 25 (2003) pg.139–147. (Elsevier). 70 ELK Asia Pacific Journals – Special Issue 13. EXPERIMENTAL INVESTIGATION OF THERMAL PERFORMANCE OF LIQUID FLAT PLATE COLLECTOR BY COMPARING SINGLE GLASS SHEET WITH THE DOUBLE GLASS SHEET TalivHussain1*,Wasiur Rahman2, Saddamul Haque3,Rocky Singh Labana4,Md.Sabbir Ali5 Department of Mechanical Engineering, Lovely Professional University Phagwara, Punjab (India) -144402 Email:
[email protected] Phone no: 08283836492 ABSTRACT- With the rapid exhaustion of natural resource there is upsurge in utilization of non-conventional resources. Being abundance in availability and non-polluting in nature they are given preference over fossil fuels. With the advancement of technical era it gave birth to new devices which are utilized to harness nonconventional energy. Few of them are solar collectors and wind mills. In this experiment we are harnessing solar energy using solar flat plate collector. We are varying the use of glass sheet to determine collector efficiency. In first instance we are using single glass sheet as the outer shield and in second instance pair of glass is used. To enhance the performance of solar collector we use toughen glass sheet, because of its better optical property. Toughen glass sheet of 5 mm is used in the experiment. After comparing and contrasting the efficiency of two experiments conducted using single and double glass sheet, we concluded that the setup having single glass sheet is more efficient than the double glass sheet. Efficiency of solar collector is enhanced by 28-32%, if single glass sheet of better optical property is taken into consideration. Keywords: Solar Flat plate Collector, Collector Efficiency. I. INTRODUCTION Proc. Of the Int. Conf: ARIMPIE-2015 With the depletion of natural resource like fossil fuels the world is on the verge of witnessing major setback of energy crisis. Energy growth is going on in arithmetic way where as its consumption is increasing in geometrical way. With the natural resources hitting new lows with each passing days, it has dented the economy of many countries which relied heavily on them. It is a matter of great concern not only for us but also for our coming generation, looking at current scenario of energy consumption it’s not very difficult to predict that the energy resource will not last much longer. The scientists are working hard on finding alternative of these resources. One of the best alternatives for prevention of depletion of the energy resources is use of non-conventional energy, which is available in abundance around us. They are majorly solar, wind and tidal energy. These natural resources are harnessed to produce energy which can be utilised for performing various activities. Non conventional energy resource turns out to be boon in this acute energy crisis situation. Non conventional energy is far much better than the fossil fuels and other resources. In terms of availability, cost, affect on environment and many more factors under which non conventional energy is preferable over fossil fuels. The only factor which underlines the advantage is its sparsely distribution across the earth. With the advancement of technical era, more and more technology is put into work to harness non conventional energy. Major products being solar cell and wind mill are the gift of technology. Our area of concern is solar liquid collector, which utilizes solar energy to heat up water which is used for domestic as well as industrial purpose. II. LITERATURE REVIEW k. Chung et al: An experiment is conducted to evaluate the pressure variation on the collector and the wind uplift force. Two suggestions are composed to reduce the wind uplift; these are lifting the model and guide plate. Wind speed used for the evaluation of wind uplift is in the range of 20-50 m/sec. There is significant effect on wind uplift using guide plate normal to the wind. The effect of lifting the model is not much effective to reduce the wind lift. Ahmet Koca et 71 ELK Asia Pacific Journals – Special Issue al: an experiment is performed to evaluate the exergy and energy performance of the integrated flat plate solar collector with phase changing material for thermal storage. Mobilterm 605 is used as a working fluid with thermal conductivity .145W/mK. PCM material used is CaCl2.6H2O. Energy and exergy efficiencies are 45% and 2.2%. Katharina Resch et al: a review is done on the Thermotropic layers used for the overheating protection. Their transmittance is the function of the temperature of the collector. At greater temperatures transmittance declines reduce the collector temperature. Thermotropic hydrogels, thermotropic polymer blends and thermotropic systems with fixed domain are mainly applied for overheating protection. Ahreza Hobbi et al: To observe the effect of heat enhancement devices on collector performance an experiment is being conducted. Basically four different types of arrangement are analyzed regular circular tube, regular tube with twisted strip tabulator, regular tube with coil spring wire and regular tube with conical ridges installed in every 152mm. There is meagre effect on the performance of collector. Hamid Moghadam et al: Developed the optimum tilt angle for the flat plate solar collector to receive maximum solar radiation. A MATLAB program is developed to evaluate the optimum tilt angle on the day basis, month basis, annual basis or any specified time interval. The results are constant with experimental data. Naiem Akhtaret et al: observed the changing effect of absorption of radiation in glass cover on the top loss coefficient for single and double glass cover. Temperature of the glass cover is increased by 6˚c in case of single glazing. Temperature of the glass cover is increased by 14˚c and 11˚c in case of double glazing. There is a difference of 49% in the value of convective heat transfer coefficient, by taking and neglecting the absorption in glass cover in case of double glazing. The correlations are developed for to compute the absorption effect in the glass cover. Y. Raja Sekhar et al: To detect the loss coefficient considering the aspects like insulation, emissivity of absorber, ambient temperature, wind loss coefficient, and tilt an experiment is conducted. Apart from experiment they are also theoretically analyzed. After analysing both experimental n analytical Proc. Of the Int. Conf: ARIMPIE-2015 process following conclusion is drawn, efficiency reduces with increment in emissivity of the plate, efficiency elevates with increase in ambient temperature, with increase in wind loss coefficient efficiency decrease, not much changes occur due to tilt on top loss coefficient. III.EXPERIMENTAL SETUP The setup used in the experiment consists of a wooden frame, a thin glass sheet, aluminium sheet, copper pipe and insulating material. The dimension of wooden frame is 900mm x 1245mm. Wooden frame is being insulated using glass wool having 5 cm thickness, copper pipe of 10 mm diameter is placed which is brazed over by aluminium sheet of 3 mm thickness. In this experiment we explore the collector efficiency yielded by the solar flat plate collector under the action of single and pair of glass. Thickness of both glass sheets is same i.e 5 mm. We make use of toughen glass as the outer covering of the solar panel where sun rays falls directly. After passing through the glass, rays reaches the aluminium plate which gets heated up due to the action of sun rays over them, this heated plate heats up the copper coil running beneath it by convective heat. Water running inside the coil also gets heated up. Water is supplied from one end of the pipe and temperature is observed at the inlet as T1, as water flows through the pipe it extracts heats from the copper coil resultant gets heated up and water received at the outlet has comparatively higher temperature than its inlet, outlet temperature is measured as T2. During first setup single glass is used in experiment and observation is recorded and then double glass is used and recording is taken accordingly. The dimensions of tubes are: 10 mm Inner Diameter of Tube 2 mm Thickness of Tube 100 mm Spacing Tubes between 72 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 1. Solar power meter 2. Temperature Sensor 3. Liquid mass flow rate Measurement 1. Solar power meter: Solar power meter is used to measure intensity of radiation falling on collector Surface in watt/m2 2. Temperature Sensor: The Dial gauge type temperature sensor is used to measure the temperature of the inlet and outlet water from the water flat plate collector. The range of the dial gauge type temperature sensor is from 0250°C. 3. Liquid mass flow rate Measurement: The liquid flow rate is measured by conventional method in which we have recorded the time required to fill the beaker of known volume. By the help of this data,we have calculated discharge(volume/time) at the outlet of the water flat plate collector. IV.CALCULATION AND RESULT Now, we can determine the efficiency of solar flat plate collector using the formula: η = mcΔt/IA Where, m= mass flow rate c= specific heat capacity Figure 1. Liquid flat plate collector Δt= T2-T1 Measuring devices and instruments I= intensity of sun rays The different parameters are measured in this study. The instruments used are as follows: A= area of solar flat plate collector Table 1. Data obtained in experiment (WHEN SINGLE GLASS SHEET IS USED) Time Outlet Temperature of water T2 (in °C)) Inlet Temperature of water T1 (in °C) Water Flow Rate Mf (kg/s) Solar Intensity I (W/m2) Temperature difference ∆T (T2-TI) (in °C) Efficiency η in % 10:00 AM 29 25 0.008 610 4 20.1 11:00 AM 33 25 0.008 680 8 35.2 73 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 12:00 PM 37 25 0.008 750 12 47.4 1:00 PM 41 25 0.008 800 16 60.1 2:00 PM 38 25 0.008 755 13 51.1 3:00 PM 34 25 0.008 685 9 40.2 4:00 PM 28 25 0.008 600 3 15.3 Table 2. Data obtained in experiment (WHEN DOUBLE GLASS SHEET IS USED) Time Outlet Temperature of water T2 (in °C)) Inlet Temperature of water T1 (in °C) Water Flow Rate Mf (kg/s) Solar Intensity I (W/m2) Temperature difference ∆T (T2-TI) (in °C) Efficiency η in % 10:00 AM 28 25 0.008 610 3 15.2 11:00 AM 31 25 0.008 680 6 26.1 12:00 PM 35 25 0.008 750 10 40.1 1:00 PM 38 25 0.008 800 13 48.4 2:00 PM 36 25 0.008 755 11 44.1 3:00 PM 32 25 0.008 685 7 31.2 4:00 PM 27 25 0.008 600 2 10.1 Single glass sheet 60 70 50 60 EFFICIENCY EFFICIENCY Double glass sheet 40 30 20 50 40 30 20 10 10 0 0 10:00 11:00 12:00 01:00 02:00 03:00 04:00 10:00 11:00 12:00 01:00 02:00 03:00 04:00 TIME TIME V.CONCLUSION collector efficiency on using single glass sheet of better quality. After conducting the experiments using same mass flow rate of water in the case of single glass and double glass sheet we came to conclude that collector efficiency is maximum for single glass cover as compare to double glass cover. Thus there is an 28-32% increase in 74 ELK Asia Pacific Journals – Special Issue Glass used Single Double sheet Maximum Efficiency (%) 60.1 48.4 Proc. Of the Int. Conf: ARIMPIE-2015 Maximum Temp. Difference (oC) 16 13 REFERENCES [1] K. Chung, K. Chang and Y. Liu, Reduction of wind uplift of a solar collector model, Journal of wind engineering and Industrial Aerodynamics, 96 (2008) 12941306 [2] Ahmet Koca Forecasting of thermal energy storage performance of Phase Change Material in a solar collector using soft computing techniques, Expert Systems with Applications, 37 (2010)2724–2732 [3] Atharina Resch Thermotropic layers for flat-plate collector – A review of various concepts for overheating protection with Polymeric materials, Solar energy materials & solar cells, 93 (2009)119-128 [4] G.D.Rai, Non-conventional Source of Energy, fourth Edition, Eighteenth reprint:2006 [5] B.H.Khan, Non-Conventional Source of Energy, Second Edition, Seventh reprint:2011 [6 ] Ismail.H. Ozsabuncuoglu, Economic analysis of flat plate collectors of solar energy, energy policy, 23, no.9 (1995)-755763 75 ELK Asia Pacific Journals – Special Issue 14. EFFECT OF PHASE CHANGE MATERIAL(PCM) AS SODIUM CHLORIDE (NACL) IN VCRS SYSTEM AS COMPARE TO SIMPLE VCRS SYSTEM Rahul Wandra1,Taliv Hussain2,Sourabh3,Neeraj Katoch4,Sahil Chadha5 Department of Mechanical Engineering, Lovely Professional University Phagwara, Punjab (India) -144402 Email:
[email protected] Email:
[email protected] Phone no: 08283836492 Abstract -The main motive of this experimental study is to investigate and develop novel approach for the COP of vapour compression refrigeration system with the help of phase change material. In Refrigeration heat transfer from low temperature reservoir to high temperature reservoir by using vapour compression refrigeration system. Here experimental study is conducted to observe the performance of phase change material. The usage of sodium chloride (NaCl) phase change material will help to improve the COP of vapour compression refrigeration system. When the environment temperature is more than that of the PCM, heat is transfered from the surroundings to the material, which creates a cooling effect and changes PCM’s state from solid to liquid. When the environment temperature is lower than that of the PCM, heat is transfered from the PCM to the surroundings, generating a warming effect and PCM changes back to its solid state. Substance with a high heat of fusion which melts and solidifies at a certain temperature is capable of storing and releasing large amounts of energy. The PCM is located behind the five sides of the evaporator cabinet in which the evaporator coil is immersed. The result depends on the type of PCM and thermal load, around 20-27% COP improvement of the refrigeration cycle has been observed with PCM in respect to without PCM. With the increase of the quantity of PCM (0.003-0.00425 m3) COP increases about 6%. Proc. Of the Int. Conf: ARIMPIE-2015 Keywords: COP, PCM, vapour compression refrigeration system. INTRODUCTION Vapour compression refrigeration system is a system, where the transfer of heat from low temperature reservoir to high temperature reservoir takes place with the help of working fluid, known as refrigerant. The vapourcompression uses a circulating liquid refrigerant as the medium which absorbs and removes heat from the space to be cooled and subsequently rejects that heat elsewhere. In vapour compression refrigeration system, the refrigerant undergoes phase change. There are many types of industrial plants that often utilize large vapour-compression refrigeration systems e.g, Oil refineries, petrochemical and chemical processing plants, and natural gas processing plants etc. The most commonly used method of cooling is with vapour-compression cycles, because it is fairly easy to construct a cooling device employing this method and the cost is low. In fact, conventional refrigerators use this method of cooling to keep drinks chilled.Air conditioners also employ a vapour-compression cycle to cool the ambient air temperature in a room. This refrigeration cycle is approximately a rankine cycle run in reverse. A working fluid is pushed through the system and undergoes state changes (from liquid to gas and back). The latent heat of vaporization of the refrigerant is used to transfer large amounts of heat energy, and changes in pressure are used to control when the refrigerant expels or absorbs heat energy. However, for a refrigeration cycle that has a hot reservoir at around room temperature and a cold reservoir that is desired to be at around 34°F, the boiling point of the refrigerant needs to be fairly low. The basic vapour compression or mechanical refrigeration cycle involves the circulation of refrigerant, which in the process of boiling (evaporating) absorbs large amounts of heat and gives up heat when condensing. This heat which must be gained or lost during the change of state is called latent heat of vaporisation. It is in general more than the specific heat,that is the heat lost or gained during a one degree change in temperature. 76 ELK Asia Pacific Journals – Special Issue LITERATURE SURVEY In 1805, the American inventor Oliver Evans described a closed vapor-compression refrigeration cycle for the production of ice by ether under vacuum. Heat would be removed from the environment by recycling vaporized refrigerant, where it would move through a compressor and condenser and would eventually revert to a liquid form in order to repeat the refrigeration process over again. However, no such refrigeration unit was built by Evans.In 1834, an American expatriate to Great Britain, Jacob Perkins, built the first working vapourcompression refrigeration system in the world. It was a closed-cycle that could operate continuously, as he described in his patent: I am enabled to use volatile fluids for the purpose of producing the cooling or freezing of fluids, and yet at the same time constantly condensing such volatile fluids, and bringing them again into operation without waste. His prototype system worked although it did not succeed commercially.The first practical vapor compression refrigeration system was built by James Harrison, a British journalist who had emigrated to Australia. His 1856 patent was for a vapour compression system using ether, alcohol or ammonia. He built a mechanical icemaking machine in 1851 on the banks of the Barwon River at Rocky Point in Geelong, Victoria, and his first commercial ice-making machine followed in 1854. Harrison also introduced commercial vapour-compression refrigeration to breweries and meat packing houses, and by 1861, a dozen of his systems were in operation in Australia and England. James M. Calm , has studied the emission and environmental impacts of the different refrigerants (R11, R123, R134a) due to leakage from centrifugal chiller system. He also investigated the total impact in form of TEWI by analyzing the direct and indirect CO2 emission equivalent due to leakage and energy consumption by the system. He studied the change in system efficiency or performance due to charge loss. He also summarized the methods to reduce the refrigerant losses by the system like design modifications, improvement in preventive maintenance techniques, use of purge system for refrigerant vapour recovery, servicing Proc. Of the Int. Conf: ARIMPIE-2015 and lubricant changing in system. Samira Benhadid-Dib and Ahmed Benzaoui , have showed that the refrigerants are widely used in both industrial and domestic equipments. These fluids, which are banned due to their environmental toxicity, are expected to be replaced. Replacing them is a difficult task considering that the only solutions currently, called "natural" refrigerants, such as ammonia, hydrocarbons and CO2. The disadvantages of these products are mainly toxicity (NH3), flammability (HC) and high pressures (CO2).Eric Granryd has enlisted the different hydrocarbons as working medium in refrigeration system. He studied the different safety standards related to these refrigerants. He showed the properties of hydrocarbons (i.e. no ODP and negligible GWP) that make them interesting refrigerating alternatives for energy efficient and environmentally friendly. But safety precautions due to flammability must be seriously taken into account.Y.S.Lee and C.C.Su have studied the performance vapour compression refrigeration system with isobutene (R600a) as refrigerant and compare the results with R12 and R22. They used R600a about 150 g and set the refrigeration temperature about 4 °C and -10 °C to maintain the situation of cold storage and freezing applications. They used 0.7 mm internal diameter and 4 to 4.5 m length of capillary tube for cold storage applications and 0.6 mm internal diameter and 4.5 to 5 m length of capillary tube for freezing applications. They observed that the COP lies between 1.2 and 4.5 in cold storage applications and between 0.8 and 3.5 in freezing applications. EXPERIMENTAL SETUP The experimental setup consists of a vapour compression system with the basic components i.e. evaporator, compressor, expansion device and condenser .The system consists of a three phase, 220V, reciprocating compressor and refrigerant R134a. Air cooled type condenser is used for their good heat transfer performance. Evaporator section is of shell and tube type using copper tubes. Refrigerant used is R134a. Different controlling elements are used like voltmeter, an ampere meter, bourdon tube type 77 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 low pressure gauge and high pressure gauge, temperature sensor. Parameters Unit and Simple VCRS system Symbol At VCRS with (Nacl) PCM At At At 30°C 27 °C 30 °C 27°C Factors affecting the performance • Amount of charge filled and system pressure • Diameter of capillary tubes working fluid property • Inlet water temperature MAJOR COMPONENTS The experimental setup consists of a single stage vapour compression system. Its main components are hermetically sealed compressor driven by a constant speed motor, an evaporator,an condenser ,a capillary tube as an expansion device and handset valve. MEASURING DEVICES Ammeter and voltmeter are used to measure the electrical current and voltage of input power respectively. The bourdon pressure gauges are used to measure the suction (inlet) and discharge (outlet) pressure of compressor. Temperatures of refrigerant and the ambient air at different points are measured by use of RTD PT100 type thermocouples. OBSERVATION TABLE Table 1: Result obtained by using PCM (Nacl) and simple VCRS Suction Pressure Bar 0.21 0.53 0.33 0.21 Discharge Pressure Bar 8.22 8.93 8.91 9.13 Evaporator Degree -11.4 Outlet Celsius(°C) 11.21 12.43 Temperature 12.33 Compressor Degree 42.13 49.87 42.55 43.20 Outlet Celsius(°C) Temperature Condenser Degree 31.92 30.32 31.37 32.14 Outlet Celsius(°C) Temperature Current Ampere(A) 1.52 1.67 0.92 1.20 Voltage Volt(V) 180 180 180 180 CALCULATIONS AND RESULTS FORMULAE USED While performing the experiment, the result obtained. Based on this result thermodynamic properties of refrigerant R134a are obtained at the different point of the system. In order to calculate the enthalpy, using the P-h chart of the refrigerant R134a and we are getting different parameters as: A. Compressor Work Wc = V * I = mref* (h2 –h1) B. Mass flow rate of refrigerant mref C. Cooling effect produced Qr = mref* (h1 –h4) 78 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 REFERENCES D. COP = Where, h1 = enthalpy of refrigerant at inlet of compressor in kj/kg (1) h2 = enthalpy of refrigerant at exit of compressor in kj/kg (2) h3 = enthalpy of refrigerant at exit of the condenser kj/kg (3) h4 = enthalpy of refrigerant at entry of evaporator in kj/kg (4) Table 2: Result of the experiment at ambient air temperature 27°C Performance result of Air Conditioner (Tamb-27°C) Simple VCRS VCRS Parameter Unit system with (Nacl) PCM Compressor work Wc Watt COP ------------ 273.6 165.6 3.73 4.63 Table 3: Result of the experiment at ambient air temperature 30°C [1] Evans, Oliver (1805). The Abortion of the Young Steam Engineer's Guide. Philadelphia, PA: Fry & Kammerer. [2] "James Harrison Evolution Refrigerators & Freezers" of Lab [3] James M. Calm, “Emissions and environmental impacts from air-conditioning and refrigeration systems,” International Journal of Refrigeration 25, pp. 293–305, 2002. [4] Eric Granryd, “Hydrocarbons as refrigerants - an overview,” International Journal of Refrigeration 24, pp. 15-24, 2001. [5] Y.S. Lee, and C.C. Su, “Experimental studies of isobutene (R600a) as the refrigerant in domestic refrigeration system,” Applied Thermal Engineering 22, pp. 507–519, 2002. [6] Samira Benhadid-Dib, and Ahmed Benzaoui, “Refrigerants and their environmental impact Substitution of hydro chlorofluorocarbon HCFC and HFC hydro fluorocarbon. Search for an adequate refrigerant,” Energy Procedia 18, pp. 807 – 816, 2012 [7] The Repertory of patent inventions [formerly The Repertory of arts ... - Google Books. Books.google.co.uk. Retrieved 2013-0110. Performance result of Air Conditioner (Tamb-30°C) Simple VCRS VCRS Parameter Unit system with (Nacl) PCM 300.6 216 Compressor Watt work Wc 3.58 4.70 COP ------------ 79 ELK Asia Pacific Journals – Special Issue 15. EXPERIMENTAL ANALYSIS OF A WASTE-HEAT-UTILIZATIONSTRATEGY USING THERMOELECTRIC DEVICE IN C.I. ENGINE R. Srivastava*, S.K. Dhiman#, J.V. Tirkey## * Department of Mechanical Engineering, I.T.S. Engg College Gr. Noida # Department of Mechanical Engineering, Birla Institute of Technology, Ranchi ## Department of Mechanical Engineering, Indian Institute of Technology (BHU), Varanasi Abstract—The present worldwide problem regarding automobiles is limitations of fuel and environmental pollution. When an internal combustion engine is operating, a large amount of energy is wasted as exhaust gas and with engine cooling. The efficiency of an internal combustion engine ranges from 30% to 40% and about 60% to 70% of the overall energy loss in a combustion engine is heat. The present experimental and computational study investigates waste heat recovery from the exhaust gas heat of an internal combustion engine using a thermocouple and heat pipes to produce electric power. This system proposes thermoelectric generation (TEG), working with heat pipes to produce electricity from a limited hot surface area. The current TEG system is directly connected to the exhaust pipe, to utilize the maximum possible heat available at the exhaust of C.I. engine. As designed, this heat recovery system produces a maximum of 1.54mV when the hot exhaust gas heats the evaporator surface of the heat pipe to 277o C. The results obtained, promises great possibilities for application of this technology in future energy-efficient vehicles. Keywords—Exhaust gas, thermoelectric generator, thermocouples, and heat pipes. I. INTRODUCTION Recent trend about the best ways of utilizing the deployable sources of energy in to useful work is to reduce the rate of consumption of fuel as well Proc. Of the Int. Conf: ARIMPIE-2015 as environmental pollution. Out of all the available sources, the internal combustion engines are the major consumers of fuel around the world. Out of the total heat supplied to the engine from the fuel, approximately, 30 to 40% is converted into useful mechanical work; the remaining heat is expelled to the environment through exhaust gases and engine cooling systems[1]. The recovery and utilization of wasteheat not only conserves fuel but also reduces the amount of waste heat and greenhouse gases damped to environment. In automobile engines significant amount of heat is released to the environment. For example, As much as 35% of the thermal energy generated from combustion in an automotive engine is lost to the environment through exhaust gas and other losses. The amount of such loss, recoverable at least partly or greatly depends on the engine load [2].However, in all the energy saving technologies used, engine exhaust heat recovery is considered to be one of the most effective. Many researchers recognized that Waste Heat Recovery from the engine exhaust gases has the potential to decrease fuel consumption without increasing emissions, and recent advancements in technology have made these systems viable and cost effective. Figure 1.1 Schematic shows total energy distributions of an I.C. engine. In present investigation the recovery and utilization of waste heat is done using thermoelectric generators [3] which is based on the principle of Seebeck effect or thermoelectric effect. The principle of Thermoelectric is the creation of electric current from a temperature gradient or the creation of a temperature gradient from a current. Thermoelectric are based on the Seebeck Effect and the Peltier Effect, which were both discovered in the early 1800's. The Peltier Effect is widely known and used in many 80 ELK Asia Pacific Journals – Special Issue electric cooling applications that vary from small digital cameras to large refrigeration units and air conditioners. The Seebeck Effect runs in reverse of the Peltier Effect. Physicist Thomas Seebeck found that if you placed a temperature gradient across the junctions of two dissimilar conductors, electrical current would flow. This is the thermoelectric concept that would be of interest, because it takes the wasted heat and converts it to useful electricity. Thermoelectric power generators convert heat energy to electricity. When a temperature gradient is created across the thermoelectric device, a DC voltage develops across the terminals. When a load is properly connected, electrical current flows. The present research posses a heat pipe thermoelectric generator [4] system which provides a large heated surface area, on which numerous thermocouples can be installed. As the heat pipe used is very efficient conducting device, it is possible to transfer a large amount of heat through the thermocouples to the heat sink. The performance of different thermocouples is described by: ZT = (α2σ/λ)T; where ‘α ’ is the Seebeck coefficient in μVK-1; ‘σ ’ is the electrical conductivity in Sm-1; ‘ λ’ is the thermal conductivity in Wm-1K-1 of thermoelectric material and ‘T’ is absolute temperature in Kelvin. Coefficient of Performance (COP) of any thermocouple basically depends on the thermal conductivity and electrical conductivity of the material in use. For better COP, there is a need for materials with low thermal conductivity and higher electrical conductivity. In the present investigations, three easily available materials i.e., copper, iron and aluminum are selected to obtain the performance of three thermocouples TC1 (Al-Cu), TC2 (Cu-Fe) and TC3 (Al-Fe) [6]. The electrical and thermal conductivity of these materials in their purest form is in the order as: copper > aluminum> iron under normal conditions. Out of these three thermocouples, TC3 was found to show good performance for various temperature differences. For future automotive vehicles, this technology offers increased fuel economy and improved engine efficiency by converting some waste heat to electricity. Proc. Of the Int. Conf: ARIMPIE-2015 II. EXPERIMENTATION In order to vary the load on a C.I. engine to obtain various output parameters, the C.I. engine was coupled to a hydraulic dynamometer using a universal coupling. A movable assembly was fabricated to mount the hydraulic dynamometer and the C.I. engine, a movable assembly is fabricated so as to move the complete experimental set up to the easily available water sources,which is provided to the Hydraulic dynamometer for load variation on the engine. The schematic of movable assembly is shown in figure2.1. Figure 2.1: Schematic shows a movable assembly. The shaft of both Hydraulic Dynamometer and the C.I. engine was made coincident using various spacers to avoid any kind of vibration and breakdown. The following objective is shown in figure 2.2. Figure2.2: Schematic shows shafts of hydraulic dynamometer and the diesel engine made coincident. Both the Hydraulic dynamometer and the C.I. engine are coupled using the universal coupling as shown in figure 2.3. Figure 2.3: coupling. Schematic shows universal A fuel measuring and supply system is fabricated which is attached to the inlet of the 81 ELK Asia Pacific Journals – Special Issue C.I. engine, start/stop valve were used to measure the accurate amount of fuel consumed by the engine for different load conditions. The mass of fuel consumed for varying load condition is measured using the fuel measuring cylinder as shown in Figure 2.4. Figure 2.4: Schematic shows fuel metering device and supply system . The actual model fabricated is shown in Figure 2.5. Proc. Of the Int. Conf: ARIMPIE-2015 the hydraulic dynamometer, thus as the brake power increases mass of fuel consumption and the temperature of the exhaust gases also increases.Different temperature of the exhaust gases at different load was obtained using a thermometer. The temperature of cold junction was always maintained at room temperature i.e. 27o C (300 K). The main components of the manufactured experimental TEG system, illustrated in Figure 2.5 are the main exhaust pipe, TEMs, and the heat pipe. The heat pipe used is a high conductive aluminium rod, 15 cm in length, 3.81 cm in outer diameter and 3 mm in thickness, it is incorporated between the exhaust of the engine and the muffler to utilize the maximum possible heat coming out of the engine [5]. This heat pipe act as the hot junction and ceramic material used act as the cold junction of the thermoelectric generator (TEG), two different wires (thermocouple) are winded on this heat pipe at one end and at other end they are attached to the cold junction. The heat pipe after winding thermocouples is made insulated at outer surface area using jute material. These thermocouples after the cold junction is attached to a scientific multimeter to complete the circuit and obtain the voltage generated due to the temperature difference at two junctions. Figure 2.6 shows theactual fabrication of the thermoelectric generator with heat pipe (aluminium rod) winded by aluminium and copper thermocouples. Figure 2.5: Schematic shows actual fabricated model. When the load on an engine is increased more power is required to maintain the same speed of the vehicle, so more amount of fuel would be supplied from the injector nozzle to the engine cylinder during compression stroke, as a result of combustion the pressure and temperature inside the engine cylinder increases because of which the temperature of the exhaust gases coming out of the engine cylinder increases rapidly. The variation of mass of fuel consumed (mf) and the temperature (T) of the exhaust gases released with Brake power is plotted on a graph for various load condition. The Brake power (B.P.) solely depends on the load provided by Figure 2.5: Schematic shows block diagram of TEG. Different voltages for different type of thermocouples were obtained for varying temperature differences. The different 82 ELK Asia Pacific Journals – Special Issue engine higher temperature can be obtained, temperature at the exhaust of the engine increases with increase in brake power. Different values of voltages are obtained at different temperature of the exhaust gases for different thermocouples. T 200 180 160 140 120 100 80 60 40 20 0 mf 1.4 Temperature (K) thermocouples used are Al-Cu, Fe-Cu and AlFe. Thermocouple TC1 and TC3 are just in twisted form because aluminum can’t be welded under normal conditions and TC2 is fabricated (without the use of third material as a binder). Proc. Of the Int. Conf: ARIMPIE-2015 1 0.8 0.6 0.4 0.2 THERMOCOUPLE TC1 TABLE 2.1 MATERIAL THERMAL 4.5777 4.0691 3.5604 3.0518 2.5432 2.0345 1.5259 1.0172 B.P.(kW) ELECTRICAL RESISTIVITY CONDUTIVITY (ohm m) (Sm-1) Al 3.2 x 10-7 3.13 x 106 Cu 2.8 x 10-7 3.6 x 106 The voltage generated depends largely on the temperature difference across the thermocouple. When these thermocouples are studied for their TC2 Fe 1.66 x 10-6 6.024 x 105 voltage generation with the temperature ranging O up to 250 C, the curves obtained for voltage 2.25 x 10-6 4.4 x 105 generation withCu temperature were parabolic in nature. Out of these three-7 thermocouples, TC3 Al 3.2 x 10 3.096 x 106 thermocouple (TC3) has best performance for the selected temperature range-6 as shown in5 fig Fe 1.5 x 10 6.7 x 10 3.1. III. 0.5086 0 0 The specifications of all the three thermocouples are listed in table 2.1 [6]. mF (kg/h) Figure 2.6: Schematic shows winding of thermocouples. 1.2 EXPERIMENTAL RESULTS AND DISCUSSION Graph 3.1 represents the experimental results obtained. As from the result we can see that as the brake power increases the mass of fuel consumption and the temperature of the exhaust gases increases. Thus by increasing load on an Graph 3.1: Variation of mass of fuel and temperature of exhaust gas with brake power. Graph3.2 shows that in normal mode, voltage generated with temperature is maximumfor aluminium-iron thermocouple (TC3) for all temperature ranges with its maximum value of 1.542mV at a temperature difference of 250o C. The experimental results from graph 3.2 conclude that thevoltage generated increases with increase in temperature of the exhaust gases, so higher voltages can be obtained for higher temperature. Aluminum-iron thermocouple shows better performance as compared to other combinations (i.e. copperaluminium TC1 & copper iron TC2) indicating the importance of combination of materials with high electrical conductivity and low thermal conductivity. For TC3 combination, aluminum fulfills the requirement of high electrical conductivity where as iron has low thermal conductivity. Aluminum shows better prospects as one of the thermocouple materials, however, difficulty arises with aluminum for the fabrication of its thermocouple as aluminum does not fuse with other materials under simple laboratory conditions. 83 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Voltage, mV engine. 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 Al-Cu CuFe 0 100 200 300 Temperature Difference, ΔT Graph 3.2: Variation Temperature difference. of voltage with IV. CONCLUSION From the present investigations it is concluded that the voltage generated depends on the temperature of the exhaust gases, as the temperature of the exhaust gases increases the voltage generated also increases. Thus for a better performance of thermoelectric generator higher temperature at exhaust is required, so the heat pipe would be more effective when it is incorporated between the exhaust pipe and the muffler. When the heat pipe is incorporated between the muffler and the exhaust pipe maximum amount of heat can be utilized by the thermoelectric generator. The above results for voltage generation using thermoelectric generator concludes that the performance of AlFe thermocouple is better than the other thermocouples used for normal mode of operation in lower as well as higher temperature range. All the three thermocouples were able to produce voltagesbut their magnitude is very low. Thus instead of using a single thermocouple for voltage generation, numerous thermocouples can be used to obtain a considerable amount of voltage. The semiconductor materials shows better electrical properties than the metal thermocouples, so semiconductors as thermocouples can be used to obtain higher voltages. A large number of N-type and P-type semiconductors can also be doped together to obtain effective voltage that will increase and enhance the performance and efficiency of the REFERENCES [1] T. Endu, S. Kawajiri, Y. Kojima, K. Takahashi, T. Baba, S. Ibaraki, T. Takahashi, “Study on maximiszngexergy in Automotive Engines,” SAE Int. Publication 2007-010257, 2007. [2] M. Hatazawa, “ Performance of a thermo acoustic sound wave generator driven with waste heat of automobile gasoline engine,” transaction of the Japan society of Mechanical engineers 70 (689) (2004) 292299. Part B. [3] J. S. Jadhao, D. G. Thombare“Review on Exhaust Gas Heat Recovery for I.C. Engine”, International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue 12, June 2013. [4] Francisco P. Brito, Jorge Martins, L.M. Goncalves and Rui Sousa Universidade do Minho “Temperature Controlled Exhaust Heat Thermoelectric Generation” 2012 SAE International,10.4271/2012-01-1214. [5] X. Liu, Y.D. Deng, S. Chen, W.S. Wang, Y. Xu, C.Q. Su “A case study on compatibility of automotive exhaust thermoelectric generation system, catalytic converter and muffler” Elsvier International Journals 2(2014)62–66. [6] Vinod Kumar, Jaspal Singh and S.S. Verma “Performance Comparison of Some Common Thermocouples for Waste Heat Utilization” Asian Journal of Chemistry Vol. 21, No. 10 (2009), S062-065. CONTACT INFORMATION F. A. Author, PG Student, Department of Mechanical Engineering at Birla Institute of Technology, Ranchi, Jharkhand, India (
[email protected]). S. B. Author, Assistant Professor, Department of Mechanical Engineering at Birla Institute of Technology, Ranchi, Jharkhand, India (
[email protected]) T. C. Author, Assistant Professor, Department of Mechanical Engineering at Indian Institute of Technology (BHU), Varanasi, Uttar Pradesh, India (
[email protected]) 84 ELK Asia Pacific Journals – Special Issue 16. EFFECT OF VARIOUS CUT-OUT ON BUCKLING ANALYSIS OF LAMINATED COMPOSITE PLATE USING FE SIMULATION Rekha Shakya*, Tushar Sharma, Bahadur Applied Mechanics Department MNNIT, Allahabad, U.P., 211004
[email protected]*
[email protected] [email protected] Rajendra Abstract— This paper investigate the buckling analysis of composite laminated plate with various cut-out (i.e., Elliptical-horizontal, Elliptical-vertical, Square, Rectangle, Circle, Diamond, Triangle) using FE simulation. The effect of buckling load on symmetric cross-ply [(0/90)2]s and angle-ply [(15/-75)2]s, [(30/-60)2]s and [(45/-45)2]s was determined on square composite laminate. These cut-outs are placed at the centre of the laminate. The buckling analysis is performed using FE simulation software Ansys 14.0 considering same area for all cutouts. The effect of position of circular cut-out placed along the center line is also investigated. Results shows that elliptical-horizontal and triangular cut-out give highest and lowest buckling load as compared to other cut-out, respectively. The results are validated with literature and show that cross-ply laminate give best result as compared to angle-ply laminate with irrespective of cut-out shape Keywords—buckling, laminated composites, different cut-out, FEM I. INTRODUCTION There are many application of composite material like marine, mechanical, aerospace, and automotive industries in which they are used, reason behind this is because they are lighter and have high strength. Composite laminate can sustain much higher load under the action of various in-plane load, such as, uni-axial compression, in-plane shear and combined in- Proc. Of the Int. Conf: ARIMPIE-2015 plane shear and compressive loads. Furthermore, cut-out are provided in these laminated structure because of various reasons, cut-outs to serve as doors and windows, ports for mechanical and electrical systems, holes for damage inspection, etc. It is necessary to understand the behavior of structural components such as buckling load, deflections, and modal characteristics, large deflection behavior, failure characteristics [1]. Ghannadpour et al. [2] performed buckling analysis of cross-ply laminated composite plate with circular/elliptical cutouts with two different boundary conditions, first case is simply supported on all edges, second case is clamped edge in unloaded edge and simply supported in loaded edge. They find that as circular cut-out diameter of square plate increases, buckling load will be decreased. They also find that buckling load with clamped boundary condition on unloaded edges is 2 times higher than the buckling load for the plate with simply supported boundary condition. Carle Pellegrino et al. [3] investigated linear and non-linear behavior of steel plates with one hole (circular/rectangular), subjected to shear loading. The influence of the position with respect to two main axes, dimension, shape (rectangular/circular) and orientation of hole were also investigated. Kumar et al. [4] studied the effects of flexural boundary conditions on buckling and post-buckling behavior of axially compressed quasi-isotropic laminate, (+45/_45/0/90)2s with various shaped cut-outs of various sizes using the finite element method. The FEM formulation is based on first order shear deformation theory and von Karman’s assumptions are used to incorporate geometric nonlinearity. The 3-D Tsai-Hill criterion is used to predict the failure of a lamina while the onset of delamination is predicted by the inter-laminar failure criterion. Ovesy et al. [5] investigated effects of cutouts on the buckling critical stresses as well as natural frequencies. To predict the behavior of the moderately thick plates containing cut-outs, A Reddy type, third order shear deformation theory of plates is applied to the development of two versions of finite strip method (FSM), namely semianalytical and spline methods. Kumar et al. [6] studied stability and failure of a composite 85 ELK Asia Pacific Journals – Special Issue laminate with a centrally placed cutout of various shapes (i.e., circular, square, diamond, elliptical-vertical and elliptical-horizontal) under combined action of uni-axial compression and in-plane shear loads. The effects of cutout shape, direction of shear load and composite lay-up on buckling and post-buckling responses, failure loads and failure characteristics of the laminate has been discussed. An efficient utilization of material strength is observed in the case of laminate with circular cutout as compared to the laminate with other shaped cutouts. Altan et al. [7] analysed buckling coefficients of symmetrically laminated reinforced concrete plates with a central rectangular hole under biaxial static compression loadings using finite element method. Composite structure of these plates has been constituted from four, six, eight and ten laminas including steel and concrete. The effect of change in central rectangular hole from the point view of size and direction on buckling coefficients is investigated in this study. Symmetrically laminated plates under biaxial in-plane loadings are taken into consideration in the analyses of simply supported and clamped boundary conditions. Obtained results are compared with each other according to a/l and b/l where a, b are the hole sizes and l is the length of the plate, respectively. Arman et al. [8] performed effect of a single circular delamination around the circular hole on the critical buckling load of woven fabric laminated composite plates has been investigated experimentally and numerically. The determination of the critical delamination diameter for laminated composite plates has been intended by using three dimensional buckling analyses. For the experiments, crossply laminated composite plates with delamination and without delamination have been produced. The experimental critical buckling loads of plates have been found by clamping from the two edges and then these results have been compared with the results obtained from the numerical analyses. For the numerical analyses, ANSYS FEA program has been used. It has been seen that the numerical buckling analysis are very close to the experimental results. Komur et al. [9] analyzed buckling behavior of woven-glass-polyester laminated composite plate having an Proc. Of the Int. Conf: ARIMPIE-2015 elliptical/circular cut-out using FEM. Parametric study is also carried out in this paper on various plates based on the shape and position of the elliptical hole. Ouinas et al. [10] studied buckling analysis of square plates with and without elliptical notch made of composite material using finite element method. The boron/epoxy laminated plates were arranged asymmetrically. In this study, a buckling analysis was carried out for square laminated composite plate with various cut-out (i.e., Elliptical-horizontal, Elliptical-vertical, Square, Rectangle, Circle, Diamond, Triangle) located at centre using FE simulation. The plate is made of woven-glass polyester composite material. The effect of position of circular cut-out placed along the center line on buckling behavior is also investigated. II. FINITE ELEMENT MODEL a. Element In the present study, Ansys 14.0 which is known general purpose finite element software was preferred as numerical tool. In this shell element were used which is SHELL281. This shell element is used for analyzing thin to moderatelythick shell structures. It is also used for layered applications for modeling laminated composite shells or sandwich construction. It is well-suited for large rotation, linear, and/or large strain nonlinear applications. The element has eight nodes with six degrees of freedom at each node: translations in the x, y, and z axes, and rotations about the x, y, and z axes. b. Material properties and Geometric model In this work, the laminated plates were taken into account having woven–glass fibers as reinforcement material and polyester as matrix material. The mechanical properties of the woven–glass–polyester composite material are listed in Table 1 [9]. In real composite applications, different plate and cutout form may be used owing to design necessities. Dimension of square composite plate considered is 120 mm x 120 mm. The thickness of square composite 86 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 plate is 1.6 mm. The boundary condition apply to laminated plate is shown in Fig. 1. Table 1. Mechanical properties of the wovenglass-polyester composite material E1=E2 (MPa) 31,610 G12 (MPa) 12 3220 0.206 To observe the buckling behavior of composite laminate plate with centrally placed cut-outs shape, cross-ply [(0/90)2]s and angle-ply [(15/75)2]s, [(30/-60)2]s, [(45/-45)2]s laminates were used symmetrically. The major axes (b) and minor axes (c) of elliptical horizontal cut-out are taken as 0.012 and 0.06 respectively. The area of cutouts considered in analysis is taken as same for all cutout shapes and is equivalent to the area of the elliptical-horizontal cut-out. . Different cutout shapes details and their dimensions are given in Table 2. Furthermore, effect of positioning of circular cut-out along center line on buckling load is also studied in this work. The area of circle for this particular case is 1/30th area of laminated plate. Different model and mesh structure were made, because of different cut-outs shape. Among them, there is one model with boundary condition and loading condition is shown in fig.1 Fig.1. Geometry, boundary & loading condition of the model Table 2. Different cutout shapes and their dimensions. Cutout shapes Cutout dimensions (in mm) Elliptical horizontal Major axis=0.012, Minor axis=0.06 Elliptical vertical Major axis =0.06, Minor axis =0.012 Rectangular length=0.06726, width=0.03363 Square Each side=0.04756 Circular Radius=0.0268 Diamond Same as square just rotate 450 Triangular base=0.07227, height=0.06259 87 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Table 3. Buckling load results with stacking sequences for elliptical horizontal and vertical cut-outs Stacking b/a=0.5, c/a=0.1, =00 b/a=0.4, c/a=0.2, =00 b/a=0.3, c/a=0.2, =00 b/a=0.5, c/a=0.1, =900 Paper result Ref [9] Present result Ref [9] Present result Ref [9] Present result Ref [9] 27.3279 27.3279 26.8142 25.5285 27.0715 25.6911 21.3457 20.1215 23.6842 23.6842 21.8233 22.5203 22.5122 23.1707 17.9382 17.8543 19.2308 19.2308 17.4165 18.5366 17.9194 18.6179 14.9614 15.1822 17.6113 17.6113 16.1759 16.9919 16.304 16.3415 13.8447 14.2105 Sequence (0/90)2s (15/-75)2s (30/-60)2s (45/-45)2s RESULT & DISCUSSION In this work, Convergence test of mesh size is done on plate with elliptical hole having dimension as b/a=0.4, c/a=0.2, α=00. No. of element on each side of plate is varied from 10 to 70 according to which size of element & total no. of element in plate decreases & increases respectively. In the first part, the result is validated with Komur et.al [9] as shown in Table.3. In this table result were validated for elliptical-horizonal cut-out and elliptical-vertical cut-out for symmetrically cross-ply [(0/90)2]s and angle-ply [(15/-75)2]s, [(30/-60)2]s, [(45/45)2]s laminates. The effect of horizontal and vertical elliptical cut-out on buckling load with [(0/90)2]s ply is shown in fig. 2. III. a b Fig.2. Effect of (a) Elliptical-horizontal & (b) Elliptical-vertical cut-out on buckling load The effect of different cut-out shape on buckling load for different stacking sequence is shown in 88 ELK Asia Pacific Journals – Special Issue Fig. 3. In case of [(0/90)2]s cross-ply laminate, steep decrement in buckling load between elliptical horizontal and rectangular cut-out, and also between circular and diamond cut-out as shown in fig.3. The elliptical-horizontal cut-out give higher value and triangular cut-out give lower value. In this case except these two, other cut-out have closer value. In case of [(15/-75)2]s laminate, there are high difference of buckling load between elliptical horizontal and rectangular cut-out, and all other cut-out have almost close value. In case of angle ply [(30/60)2]s, [(45/-45)2]s laminates, from rectangle to diamond cut-out there are closer value of buckling load. The difference between buckling loads among all these laminates [(0/90)2]s crossply laminate give highest buckling load as comparison to all other laminates. In each case of laminate, elliptical horizontal cut-out give maximum buckling load and triangular cut-out give minimum buckling load. From rectangular to diamond cut-out, there are closer value of buckling load for angle-ply [(15/-75)2]s, [(30/60)2]s, [(45/-45)2]s laminates, whereas decrement is occurred with high value from circular to diamond cut-out. Furthermore, the buckling load of all cut-out shape give closer value for [(30/60)2]s, [(45/-45)2]s laminates, and much closer value obtained for triangular cut- out. Meanwhile diamond cut-out give much closer value for cross-ply [(0/90)2]s and angle-ply [(15/-75)2]s, laminates. The highest value of buckling load are calculated for [(0/90)2]s plates, while the lower values are computed for angleply [(45/-45)2]s. In other words cross-ply [(0/90)2]s plates give best results as comparison to all other angle-ply. Proc. Of the Int. Conf: ARIMPIE-2015 Fig. 3. Effect of different cut-out on buckling load Fig. 4. Effect of positioning of circular cutout on buckling load 89 ELK Asia Pacific Journals – Special Issue a Proc. Of the Int. Conf: ARIMPIE-2015 b laminate. The buckling analysis is performed using FE simulation software Ansys 14.0 considering same area for all cut-outs. The effect of position of circular cut-out placed along the center line is also investigated. Based on result of present investigation, following important conclusions can be drawn: d c e Fig. 5. Nodal solution result for (a) Circular, (b) Square, (c) Diamond, (d) rectangular & (e) Triangular cut-out The effect of different cut-out on nodal solution calculate from FE simulation software Ansys for [(0/90)2]s ply is shown in Fig. 5. The effect of positioning of circular cut-out along x-axis on buckling load is also investigated. For this analysis square plate with circular cutout is selected, and Circular hole is moved from left to right on central line for [(0/90)2]s plates. In the centre of plate buckling load value is lowest as shown in fig. 4. As the circular hole is moved apart from centre buckling load increases, it means it strength increases as position of circular cut-out moved away from centre. CONCLUSIONS In this paper, buckling response of square composite laminated plate with various cut-out (i.e., Elliptical-horizontal, Elliptical-vertical, Square, Rectangle, Circle, Diamond, Triangle) made of woven-glass-polyester composite material using FE simulation is investigated. These cut-outs are placed at the centre of the Stacking sequence (0/90)2s, have maximum buckling load on comparing with other stacking sequences. Laminate with elliptical horizontal cutout have maximum buckling load, while laminate with triangular cut-out have minimum buckling load. Triangular cut-out and rectangular cut-out give much closer value for angle-ply [(30/60)2]s, [(45/-45)2]s laminates. Diamond cut-out give much closer value for cross-ply [(0/90)2]s and angle-ply [(15/-75)2]s, laminates. Buckling load increases as the circular cutout moves from centre to edges, means laminate plate is weaker in centre of plate and as the circular cut-out moved away from centre it strength increases. REFERENCES [1] YH Zhang, CH Yang, "Recent developments in finite element analysis for laminated composite plates," Compos Struct, vol. 88, pp. 147-57, 2009. [2] S.A.M. Ghannadpour, A. Najafi, B. Mohammadi, "On the buckling behaviour of cross-ply laminated composite plates due to circular/elliptical cutouts," Composite Structures, vol. 75, pp. 3-6, 2006. [3] Carle Pellegrino, Emanuele Maiorana, "Claudio Modena. Linear and non-linear behaviour of steel plates with circular and rectangular holes under shear loading," J.Thin-Walled Structures, vol. 47, pp. 607616 2009. [4] Dinesh Kumar, S.B Singh, "Effect of boundary condition on buckling and post- 90 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 buckling responses of composite laminate with various shaped cut-outs," J.Composite Structure, vol. 92, pp. 769-779 2010. [5] H.R Ovesy, j. Fazilati, "Buckling and free vibration strip analysis of composite plates with cutout based on two different modeling approach," J.Composite Structures, vol. 94, pp. 1250-1258, 2012. [6] Dinesh Kumar, S.B.Singh, "Stability and failure of composite laminate with various shaped cut-outs under combined in-plane loads," J.Composite, vol. Part B 43, pp. 142149, 2012. [7] Mehmet Fatih Altan, and Murat Emre Kartal, "Investigation of buckling behavior of laminated reinforced concrete plates with central rectangular hole using finite element method," Materials and Design, vol. 30, pp. 2243–2249, 2009. [8] Yusuf Arman, Mehmet Zor, Sami Aksoy, "Determination of critical delamination diameter of laminated composite plates under buckling loads," Composites Science and Technology, vol. 66, pp. 2945–2953, 2006. [9] M. Aydin Komur, Faruk Sen , Akın Atas, Nurettin Arslan,"Bucklinganalysis of laminated composite plates with an elliptical/circular cutout using FEM," Advances in Engineering Software, vol. 41, pp. 161–164, 2010. [10] Djamel Ouinas, Belkacem Achour, "Buckling analysis of laminatedcomposite plates [(h/_h)] containing an elliptical notch," Composites, vol. Part B 55, pp. 575–579, 2013. 91 ELK Asia Pacific Journals – Special Issue 17. TO EVALUTE THE PERFORMANCE OF VCRS SYSTEM BY COMPARING LESSER SUPERHEATED REFRIGERANT(R-134a) TO HIGHER SUPERHEATED REFRIGERANT (R143a) Rahul Wandra1* ,Taliv Hussain2, Jagannath Verma 3,Arjun Sharma4,Gourav Roy5 Department of Mechanical Engineering, Lovely Professional University Phagwara, Punjab (India) -144402 Email:
[email protected] Email:
[email protected] Abstract:- Starting from the era of refrigeration and air conditioning system, superheating continuous to be conspicuous topic in basic refrigeration system. In a conventional cooling system refrigerant superheating inside the system is majorly responsible for maximum energy losses. In this paper we have concentrated on the more accurate approach of effect of refrigerant superheating on refrigeration effect of modified vapour compression system and further investigate the work input in compressor and volumetric efficiency. By undertaking different configuration and different models of compressor it is well evaluated that compressor plays a big role in refrigerant superheat losses where superheat is not only responsible for compression losses but also effects positively on refrigeration effect .Experimental results show that the COP of simple vapour compression system with lesser superheated refrigerant is 3.5 where as the COP of vapour compression system with higher superheated refrigerant is 3.17 by varying different ambient air conditions. VCRS having more superheated refrigerant R134a decreases coefficient of performance (COP) by 9.4% and this paper will give us the clear evidence that what would be the required conditions that can fulfill our control over COP. Keyword: COP, VCRS, Superheating. Proc. Of the Int. Conf: ARIMPIE-2015 INTRODUCTION Refrigeration is a technology which absorbs heat at low temperature and provides temperature below the surrounding by rejecting heat to the surrounding at higher temperature. In a refrigerator heat is continuously pump from lower temperature to higher temperature. According to second law it can be possible only with aid of external work done. The substance which works in a system to extract heat from a cold body and to deliver it in a hot body is known as refrigerant. Here in our study R-134a refrigerant is of our interest. Vapour compression refrigeration cycle is an improved type of air refrigeration cycle. It consists of four main components like condenser, compressor, evaporator and expansion valve. Here in this paper we will analyses the effect of change in operating Condition like superheating on the performance of the vapour Compression cycle. Superheating or boiling delay is the phenomenon in which liquid is heated to a higher temperature then its standard boiling point without actual boiling. Main objective of our study is to know superheating effect on refrigeration effect, work input, coefficient of performance and Volumetric efficiency of compressor in presence or R-134a as a refrigerant. LITERATURE SURVEY Domanski and McLinden [1992] presented simulation results showing different relative rankings of refrigerants studied depending on the cycle used for performance comparison (llsl-hx or reversed Rankine cycle).Goswami et al. [1993] employed an evaporative cooling on existing 2.5 Ton Trane Heat Pump by using four media pad of cellulose bound cardboard structures around the outdoor placed condenser. The thickness of the media was 20.32 cm. They reported electric energy saving of 20% for the retrofitted system when ambient temperature was 34°C.Yueming.Li et al. [2009] developed the special simulation module for water-cooled VRF based on the Energy Plus's codes, and using manufacturer's performance parameters and data. He embedded that simulation module in the software of Energy Plus. After modeling and testing the new module, on the basis of a typical office building in Shanghai with water- 92 ELK Asia Pacific Journals – Special Issue cooled VRF system, the monthly and seasonal cooling energy consumption and the breakdown of the total power consumption were analyzed. The simulation results showed that, during the whole cooling period, the fan-coil plus fresh air (FPFA) system consumed about 20% more power than the water-cooled VRF VRF system and the air-cooled VRF system was performed too. All of these provided designers some ideas to analyze the energy features of this new system and then to determine a better scheme of the air conditioning system..Pongsakorm et al. [2013] modelled and experimentally studied the performance of an inverter air conditioner with evaporative cooled condenser. For 1 Ton refrigeration, 15 cm thickness of cellulose media pad was used. At lower frequency range, COP observed was maximum. Proc. Of the Int. Conf: ARIMPIE-2015 Ammeter and voltmeter are used to measure the electrical current and voltage of input power respectively. The bourdon pressure gauges are used to measure the suction(inlet) and discharge(outlet) pressure of compressor. Temperatures of refrigerant and the ambient air at different points are measured by use of RTD PT100 type thermocouples. Before temperature measurement, the surface of the tubes are polished for removing any type of dust or rust and then the thermocouples are laid down onto the surface. Insulation tapes are wrapped around the copper tubes to prevent any heat losses to ambient air. EXPERIMENTAL SETUP In this project our main focus concentrated on the air conditioner i.e. Superheated VCRS by employing external source of superheater and Less superheated cycle. It was seen that performance of the refrigerator can be further analysed by introducing superheating system in between the outlet of evaporator and inlet of compressor and this is done by installing external superheater. In case of less superheated cycle system air cooled condenser has been used generally right now. The experimental setup consists of a single stage vapour compression system with the basic components i.e. evaporator, compressor, expansion device ,condensers and a external super heater source. The coil type heat exchanger has been attached in series after condenser and parallel to the suction line before compressor. The shifting of air cooled air conditioning system to the subcooled i.e.(system with heat exchanger) air conditioning system is done with the help of the system of hand set valve attached. The whole experiment is carried out on R134a (tetra flouroethane) which is used as refrigerant in setup. After taking the desired numerical figure of reading systemize. system with superheating ,and then we perform the same experiment with air cooled condenser. EXPERIMENTAL RESULT OF DIFFERENT AMBIENT TEMPERATURES Ambient Air Conditions : DBT - 28°C Parameters Symbol Unit Evaporator absolute Pressure Condenser absolute Pressure Evaporator exit Temperature Compressor exit Temperature Condenser exit Temperature Total electric current Peva bar Total electric voltage Less superheated cycle High superheated cycle 10.1 3.48 Pcon Bar 10.4 13.98 T1 °C 10 10 T2 °C 80 57 T3 °C 16.64 42 I Ampere 2.12 1.4 V Volt 225 225 93 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Ambient Air Conditions : DBT - 33°C Parameters Symbol Unit Less superheatedr Evaporator absolute Pressure Condenser absolute Pressure Peva Bar 0.98 High superheated VCRS 0.157 Pcon Bar 9.8 1.0166 Evaporator exit Temperature Compressor exit Temperature Condenser exit Temperature T1 °C -18 15 T2 °C 41 80 T3 °C -18 40 Total electric current Total electric voltage I Ampere 1.911 2.533 V Volt 225 225 Chart for comparison of COP and compressor work for two different cycles on the basis of two different ambient temperatures. Here in this chart we are comparing two cycles one is highly superheated and other is less superheated . we plot this chart on the basis of different ambient temperature .Its easily visualize us in this graph that less superheated cycle attain high coefficient of performance where as high superheated cycle contains less coefficient of performance. PH CHART COMPARISON OF TWO VCRS CYCLES Her we have two different cycles one is highly super heated and second cycle is less superheated VCRS cycle. After visualizing the chart we can easily able to analyses the fact that with increase of ambient temperature no doubt COP will gradually decrease and also with respect to less superheated cycle superheated cycle decreases more then later cycle. EXPERIMENTAL DISCUSSIONS RESULTS AND Here in this research paper our group member job was to identify the effect of superheated 94 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 VCRS system i.e system with external superheating and non superheated VCRS i.e. air cooled refrigeration system or less superheated cycle .Here we have also comparing the results of both superheated VCRS system and less superheated cycle, experimental tests are performed consecutively in two stages. During our first stage of experiment, less superheated cycle is being operated and so that we will be able to get some valuable numeric figure, in the second stage superheated VCRS system is used under the same ambient conditions. Data are not recorded rapidly but its taken after a steady state condition is achieved in the system so that properties of refrigerant remain constant in the system. Experimental tests are performed at three ambient temperatures i.e. 28°C and 33°C in order to have better understanding of the system behavior under different climatic conditions CALCULATIONS Based on the experimental results, thermodynamic properties of the refrigerant at different points in the cycle are obtained using the P-H chart of refrigerant R-134a and the parameters such as mass flow rate, cooling capacity and COP of the system are calculated from the equations: Performance Results of Air Conditioner (Tamb - 28oC) Less superheatedV Parameter Unit superheated Variation(%) CRS cycle Compressor Work , Wc Coefficient of performance (COP) Watt 315 477 51.4% - 4.18 3.71 -11.2% Performance Results of Air Conditioner (Tamb - 33oC) Less superheated Parameter Unit Super Variation heated VCRS (%) Cycle Compressor Work , Wc Coefficient of performance Watt 430 570 32.5% 3.7 3.32 -10.2% a. (COP) Compressor Work Wc = V * I = mref* (h2 – h1) b. Mass flow rate of refrigerant mref c. Cooling effect produced Qr=mref* (h1 –h4) d. COP = Where, h1 = enthalpy of refrigerant at inlet compressor in kj/kg (1) h2 = enthalpy of refrigerant at exit compressor in kj/kg (2) h3 = enthalpy of refrigerant at exit of condenser kj/kg (3) h4 = enthalpy of refrigerant at entry evaporator in kj/kg (4) of of the of The voltage and ampere of the input power are obtained from the voltage meter and ampere meter attached in the experimental set-up. Using this voltage and ampere reading, work done of the compressor is obtained Table 1, 2 and 3shows the results obtained from the observations recorded at three different ambient air temperature i.e. 28°C and 33°C CONCLUSION In this experiment a superheated VCRS with heat exchanger and air simple air cooled VCRS is experimentally investigated. Experimental results show that there is considerable decrease in the COP of the superheated VCRS as compare to air cooled VCRS and further there is significant increase in compressor work for 95 ELK Asia Pacific Journals – Special Issue superheated vcrs system as compared air cooled vcrs. In case of superheated VCRS there is decrease in the steady state COP from 3.7 to 3.32 under the following conditions: the wetbulb temperature is 21°C, dry-bulb temperature is 29°C, air velocity is 2.4 m/s and power consumption is increased by 29% whereas as COP decrease by 10%. The experimental investigation also verifies that compressing temperat0ure and pressure increases in case of superheated VCRS system which increases the compressor work. The superheated VCRS system thus results in increasing refrigeration effects and increasing power consumption of the compressor which consequently lead to loss of energy. Thus the use of superheated system with superheater will increase the peak load conditions of power network in extreme hot weather conditions because vapour compression air conditioners are the main cause of peak loads At last it can be well concluded that with high superheating, we can greatly increases the refrigeration effect ,hence ultimately cooling effect of refrigeration but at the same time work required in compressor is also increased and which consumes higher power then less superheated VCR cycle and also this research paper can easily visualize us that in case of high superheated cycle coefficient of performance of refrigeration decreases gradually with increase in ambient temperature. Proc. Of the Int. Conf: ARIMPIE-2015 refrigerants” Int. Commun. Heat Mass Transf. ,735-1935 [ 4] J. Chen, J. Yu, Performance of new refrigerant cycle using refrigerant mixture R32/ R134a for residential air-conditioner applications, Energy and Buildings 40 (2008) 2022–2027. [5] Klein, S. A., 2010. Engineering Equation SolverLemmon EL, McLinden MO, Huber ML, 2002, [6] REFPROP 7.0, NIST, USA. [7] ISI CODE for testing refrigerators no. 1476-1979 [8] Gosney W B, The maximum coefficient of performance of a refrigerant ,paper 2.74, XII international congress of refrigeration, Madrid,1967. [9] ASHRAE , handbook of fundamentals, 1973 [10] S. Pongsakorn, S. Thepa, 2013, “Modeling and experimental study on the performance of an inverter air conditioner using R-410A with evaporative cooled condenser”, Applied Thermal Engineering, 51, 597-610. REFERENCES [1] Pramod Kumar (2002) “Finite time thermodynamic analysis of refrigeration and air conditioning and heat pump systems” PhD thesis, Indian Institute of Technology, Delhi, N D. Arora, C.P. (2010), [2]“Refrigeration and Air conditioning”, 3rd edition, Tata McGraw Hill, New Delhi [3] A.S. Dalkilic , S. Wongwises,”a performance comparison of vapour compression refrigeration system using various alternative 96 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 18. KINEMATIC DESIGN OPTIMIZATION OF PLANERLINK MECHANISM BASED MANIPULATOR optimizing kinematic performance of the manipulators based on the motion and force manipulability concepts. Klein and Blaho [7] use the minimum singular value as a measure. Gosselin and Angeles [8] applied a global conditioning index to four different cases, which is based on the distribution of the condition number of the Jacobian matrix over the entire manipulator workspace. Park and Brockett [9] introduced the kinematic distortion index, which is a measure of the distortion associated with the mapping from configuration to work space. Singh and Rastegar [10] developed global velocity ellipsoid concept, which represents the velocity transmission characteristics of a manipulator. Doel and Pai [11] introduced formalism for the systematic construction of performance measures of robot manipulators in a unified framework based on differential geometry. Kircanski [12] determined the isotropic configurations of planar and spatial manipulators in the form of polynominal. Zanganeh and Angeles [13] introduced a set of conditions for the submatrices of the Jacobians under which a parallel manipulator can attain an isotropic configuration. Matone and Roth [14] investigated the effects of actuation schemes on the minimum singular value, the manipulability and the condition number measures of kinematic performance. Bhavesh Patel [15] represented the state of art of the kinematics of planer mechanisms. Also, Bhavesh Patel [16] investigated the force effects on the planer mechanisns. Jagdish M Prajapati Department of Mechanical Engineering The M S University of Baroda Vadodara, India
[email protected] Abstract-This paper presents optimized kinematic design of a planer mechanism (4-link) based planar manipulator is presented in this paper. In case of the parallel manipulator, there is only one location defined between force and motion where local mobility index is one. In this paper, for maximum local mobility index, optimum link lengths of the manipulator that is function of the location of the input link are obtained. Charts, showing the optimum kinematic design of the 4 – link planer manipulator are obtained. It is clear from this result, that the performance of the manipulator is maximum for a position interval in addition to a certain position. Also, at some positions better relationship between force and motion is observed where local mobility index is not exactly unit. Keywords: Optimal kinematic design; Local mobility index; Force manipulability I. INTRODUCTION To design a kinematic optimum manipulator is the central focus of researchers. Some criteria are there to design robotic manipulators. Yoshikawa [1] introduced the concept of endeffector manipulability as a measure of the kinematic transmission characteristics of manipulator. One of the most important criteria in the optimal robot design is that the robot can achieve isotropic configurations. The equal forces may be exerted in all directions. Salisbury and Craig [3] proposed to use the ratio of the largest and smallest singular values of Jacobian matrix. The most manipulability measures have been derived from the condition number of the Jacobian matrix, and have been used by Asada, Chiu and Park [4], [5] and [6] for analyzing and This paper presents how the link lengths are optimized for the closed-loop, four-bar planer mechanism as a manipulator with the help of local mobility index. The performance index is defined as the ratio between the minimum and maximum joint torque vector norms. For the investigated manipulator, optimum link measurements that maximize the performance index have been achieved based on the position of the input link. Comparing these results with those of the parallel manipulator, it is seen that better conditions are reached in terms of forcemotion relationship with the planar manipulator. 97 ELK Asia Pacific Journals – Special Issue Nomenclature length of the input link 2 length ratio of the input link 2 length of the coupler link length ratio of the coupler link length of the output link Proc. Of the Int. Conf: ARIMPIE-2015 rotation. Manipulator with a parallelogram mechanism is a special case of the four-bar mechanism consisting of equal two opposite links. When the end-effector position is taken as the task domain position vector, the Jacobian matrix is defined as the matrix representing the transformation mapping the joint rates into the cartesian velocities. This transformation is written as length ratio of the output link (1) length of the input link 1 derivative of 92 with respect to q Jacobian matrix Where is the vector of joints rates and is the vector of cartesian velocities, the Jacobian matrix is given by generalized Jacobian matrix coefficients of Freudenstein's (2) equation { } vector of joints rates rotation of the input link 1 rotation of the output link rotation of the output link (end- effector) end-effector link length ratio { } vector of cartesian velocities local mobility index rotation of the input link 2 II. MOTION MANIPULABILITY CHARACTERISTICS The planar manipulator with a four-bar mechanism under study is shown in Fig. 1. Planar manipulator with a four-bar mechanism has two actuators that are fixed to the base link and drive the two input links. One of the links in a four-bar mechanism connected to the input link 1 oscillates while the other has a full Fig. 1. The planar manipulator with a four-bar mechanism. where is the derivative of the auxiliary coordinates with respect to and is the link length ratio. As seen in Fig. 1, expression can be written. In this case, is obtained. The derivative can be determined by Freudenstein's equation. Freudenstein's equation is a displacement equation for the four-bar linkage, which holds true for each position of the linkage. In a compact form, it writes (3) 98 ELK Asia Pacific Journals – Special Issue Where Proc. Of the Int. Conf: ARIMPIE-2015 , , , , , , , , (4) Thus, the force manipulability at the mechanism's endpoint is at its worst. On the other hand, the force manipulability is at its best when a force is exerted in the direction of eigenvector emin. The local mobility index (LMI) is denned as the ratio between the minimum and maximum eigenvalues of the generalized Jacobian matrix , Lee (1993): , (11) (5) The angle δ is found explicitly as a function of p and the parameters L2, L3, L4. Such a solution is obtained by expressing sinδ and cosδ in terms of tan(δ/2), (6) (7) and substituting those values in Eq. (3), the angle θ2 is found as shown below Using the above equations, derivative ω in the Jacobian matrix is expressed as The local mobility index is bounded as . The best-conditioned point is identical to an isotropic point where local mobility index equals one. This indicates that the joint torque vector norms are equal for endpoint force exerted in any direction. The isotropic point is a special condition where the mechanism has a uniform mobility in all motion directions. The local mobility index of the planar manipulator shown in Fig. 1 can be derived from the generalized Jacobian matrix as (8) or (9) The generalized Jacobian matrix, , defined as the quadratic form of the Jacobian matrix, , is used to characterize the force manipulability of the mechanism. can be written as the product of two matrices: (10) The propagation from the input joint torques to the output end effector force is directly proportional to the eigenvalues of . If the eigenvalues of the generalized Jacobian matrix are σmax and σmin, one can conclude that when the endpoint force is in the direction of eigenvector related to the maximum eigenvalue of , the largest to exert a unit endpoint force. (12) The expression LMI in Eq. (12) defines a five-variable function depending on the input link position ρ as seen in Eqs. (4)-(9) and dimensionless link lengths L2, L3, L4 and . For the subject of optimal kinematic design of planar manipulator with four-bar mechanism, variables L2, L3, L4, which are the characteristic dimensions of this mechanism and variable , which determines the position of the endeffector on output link have been used. In order to generalize the results, using the length of input link 1, link lengths have been made 99 ELK Asia Pacific Journals – Special Issue dimensionless. The design variables , L2 and L4 which maximize the objective function LMI have been searched in the study. In the derived numerical results, first and later , L2; ., L2 and L4 variables left free, respectively and the optimization problem is solved giving constant values to the other variables. The unconstrained optimal design problem is solved by employing Newton's method iteratively, Papalambros (2000). III. NUMERICAL EXAMPLES The performance index of the manipulator for a parallel planar manipulator with equal opposite link lengths is drawn in Fig. 2 using L2 = 0.3, L3 = 1 and L4 = 0.3 numerical values and depending on input link and end-effector position. As seen in this figure, the = π/4 position of the input link and = 0.707107 value for the end-effector position equal local mobility index to one in such a parallel manipulator. These values obtained for the manipulator with parallelogram mechanism are the same with results for the planar two link manipulator obtained in the studies of optimal kinematic design by Gosselin and Angeles [8], Singh and Rastegar (1995), Kircanski (1996) and Lee et al. (1993). Proc. Of the Int. Conf: ARIMPIE-2015 L2 as design variables graph with L3 = 1 and , L2 and L4 as Fig. 3. The maximum local mobility index joint angle ( , L2 = 0.3, L3 = 1, L4 = 0.3) versus joint for parallel Fig. 3 displays the maximum local mobility index values obtained by the optimization of different link lengths of the manipulator depending on the position . As seen in graph (full line), if only the value is optimized, local mobility index equals 1 at = /4, = 0.707107 point. With L3 = 1, L4 = 0.3 constant values and and v/s design variables graph (dashed line) are derived. It is seen in these graphs that with the variable-length manipulator, the performance index can be kept at its maximum value in a position interval. As the number of free design variable increase, force-motion quality rises. As seen in the graph, it is possible to keep performance index constant at its maximum value from ρ = 0 to approximately 1.2 rad. position by the optimization of l2 and variables. This position can be increased to approximately 1.4 rad. by the optimization of , L2 and L4. Such a manipulator which has a higher kinematic performance than that of a parallel manipulator can be realized through hydraulically actuated linkage. IV. Fig. 2. The local mobility index angle and the link length ratio manipulator. (dotted line), CONCLUSION Optimal kinematic design of planar manipulator with a four-bar mechanism has been presented. The performance index is defined as the ratio called local mobility index between the minimum and maximum eigenvalues of the generalized Jacobian matrix. For the manipulator, the link measurements that maximize the performance index depending on the input link position have been found. The attained results have been compared to those of the parallel manipulator and it is seen that better results have been achieved in terms of forcemotion relationship. The force-motion performance of the manipulator can be elevated by the optimization of two design variables with setting the input link long and end-effector 100 ELK Asia Pacific Journals – Special Issue position short formerly, from the beginning of the motion and vice versa latter. In this case, the performance index can be kept at its highest value from = 0 to approximately 1.2 rad. position. If the optimization problem is solved with three variables as the output link length is added among the design variables, it is possible to raise this interval to 1.4 rad. As a result of the comparisons, better conditions have been obtained in terms of force-motion relationship also at the other points in addition to this maximum value of the performance index. As the number of free design variables increases, quality of the force-motion is possible to be raised. REFERENCES [1]. T. Yoshikawa, (1985) Dynamic manipulability of robot manipulators, Journal of Robotics Systems 2 (1) pp. 113124. [2]. T. Yoshikawa, (1985) Manipulability of robotic mechanism, The International Journal of Robotics Research 4 (2) pp. 3-9. Proc. Of the Int. Conf: ARIMPIE-2015 [8]. C. Gosselin, J. Angeles, (1991) A global performance index for the kinematic optimization of robotic manipulators, Journal of Mechanical Design 113, pp. 220226. [9]. F.C. Park, R.W. Brockeet, (1994) Kinematic dexterity of robotic mechanisms, The International Journal of Robotics Research 13 (1), pp. 1-15. [10]. J.R. Smigh, J. Rastegar, (1995) Optimal synthesis of robot manipulators based on global kinematic parameters, Mechanism and Machine Theory 30 (4), pp. 569-580. [11]. J. K. Doel, D. Pai, (1996) Performance measures for robot manipulators: a unified approach, The International Journal of Robotics Research 15 (1), pp. 92-111. [12]. M. Kircanski, (1996) Kinematic isotropy and optimal kinematic design of planar manipulators and a 3-DOF spatial manipulator, The International Journal of Robotics Research 15 (1), pp. 61-77. [3]. J.K. Salisbury, J.J. Craig, (1982) Articulated hands: force control and kinematic issues, International Journal of Robot Research 1 (1) pp. 4-17. [13]. K.E. Zanganeh, J. Angeles, (1997) Kinematic isotropy and the optimum design of parallel manipulators, The International Journal of Robotics Research 16 (2), pp. 185-197. [4]. H. Asada, K. Yosef-Toumi, (1986) Analysis and design of a direct-drive arm with a fivebar-link parallel drive mechanism, ASME Journal of Dynamic Systems Measurement and Control 106, pp. 225-230. [14]. R. Matone, B. Roth, (1997) The effects of actuation schemes on the kinematic performance of manipulators, Journal of Mechanical Design 119, pp. 212-217. [5]. S.L. Chiu, (1988) Task compatibility of manipulator postures, The International Journal of Robotics Research 75(5), pp. 1321. [15]. B. P. Patel, J. M. Prajapati, (2011) A review on Kinematics of Hydraulic Excavator’s Backhoe Attachment, International journal of engineering science and technology, 3(3), pp. 1990 - 1997. [6]. F.C. Park, J.W. Kim, (1988) Manipulability of closed chains, ASME Journal of Mechanical Design 120, pp. 542-548. [7]. C.A. Klein, B.E. Blaho, (1987) Dexterity measures for the design and control of kinematically redundant manipulators, The International Journal of Robotics Research 6 (2), pp. 72-83. [16]. B. P. Patel, J. M. Prajapati, (2012) Evaluation of Resistive Force using Principle of Soil Mechanics for Mini Hydraulic Backhoe Excavator, International Journal of Machine Learning and Computing, Vo. 2 No. 4, pp. 386 – 391. 101 ELK Asia Pacific Journals – Special Issue 19. IN-PLANE FREE VIBRATIONS OF SYMMETRICALLY LAMINATED RECTANGULAR COMPOSITE PLATES Kumar Pankaj1,a, Ujjwal Bhardwaj2,b, Priyanka Singh2,c 1 Department of Mechanical Engineering, I.T.S Engineering College, Greater Noida, U.P. 201308, India 2 Department of Civil Engineering, I.T.S Engineering College, Greater Noida, U.P. 201308, India 3 Department of Civil Engineering, Dronacharya College of Engineering, Gurgoan, Haryana 122001, India a
[email protected],
[email protected], c
[email protected] b Abstract: This work presents accurate upperbound solutions for free in-plane vibrations of single-layer laminated rectangular composite plates with an arbitrary combination of clamped and free boundary conditions. A Ritz method with a simple, stable and computationally efficient set of trigonometric functions is developed to obtain accurate in-plane modal properties of rectangular plates with arbitrary uniform elastic edge restraints. In-plane natural frequencies and modes shapes are calculated by the TRM. Reliability of the method is assessed by comparison with known solutions for square composite plates. Influence of degree of orthotropy, aspect ratio and boundary conditions upon the in-plane vibration behavior are discussed. Effects of uniform elastic spring stiffness on the in-plane natural frequencies and modal shapes are also presented. Keywords:Laminates, Composites, In-plane vibration, Ritz method, Trigonometric set I. INTRODUCTION Composites are engineering materials made from two or more materials with significantly different Proc. Of the Int. Conf: ARIMPIE-2015 properties which remain distinct on a macroscopic level within the entirety of the structure. It can be defined as a mixture of two or more mechanically separable materials that when combine, give properties superior to the properties of the individual components. Composite materials like carbon-fiber reinforced polymer, plywood, aramid fiber laminates and fiberglass laminates have been used in a multitude of applications. The mechanical properties of composites are generally not isotropic, but orthotropic. Composites serve as lighter substitutes for their metallic, isotropic counterparts. This is especially apparent in the aerospace industry. Free vibration analysis of composite plates plays a key role in many engineering applications, such as civil, aerospace, marine, automotive structural components, electronic circuit boards, energy scavenging devices and optical and mechanical equipments. Vibration is totally a mechanical phenomenon whereby oscillations occur about an equilibrium point. And free vibration occurs when a mechanical system is set off with an initial input and then allowed to vibrate freely. In-plane vibration is different from the flexural vibration. Here in-plane means only two components is considered for the vibration analysis i.e. vibrating body is said to be in plane only. Although relatively less references can be found in the wide literature to deal with in-plane vibration of rectangular plates, confident prediction of membrane modal behavior of plate systems can be of key importance in some engineering applications, like vibration transmission in built-up structures and/or vibration excitation due to fluid turbulent boundary layer or forces not perfectly perpendicular to the middle plane. In the past literatures there are many methods discussed to analyze the in-plane free vibrations of rectangular plates. D.J. Gorman. (June 2006) [1] developed the exact solutions for the free inplane vibration of rectangular plates with two opposite plate edges are given either type of simple support, the other two edges being given any combination of classical edge conditions. 102 ELK Asia Pacific Journals – Special Issue The first of simple support is characterized by null displacement parallel to the edge as well as normal stress perpendicular to the edge and the second type of support, where the displacement normal to the edge is fully restrained as well as the shear stress along the edge. Each type of simple support is shown to be analogous to the well-known simple support edge conditions encountered in the flexural vibration analysis of rectangular plates. Y.F. Xing, B. Liu. (March 2009) [2] derived all possible exact solutions for the free in-plane vibrations of a rectangular plate by using a direct separation of variables approach. Using the Rayleigh quotient variational principle, all classical boundary conditions including two distinct types of simple support boundary conditions are formulated undergoing in-plane free vibrations for rectangular plate. A numerical approximate method is required when any arbitrary combinations of supporting edges or lay-ups other than cross-ply are involved. From the literature review it is found that there are mainly four methods have been adopted for achieving analytical type in-plane vibration solutions of plates. These are the Ritz method, the Kantorovich method, the superposition method and the Fourier series method. The approaches in which summation of continuous differentiable functions are assumed as the displacement solutions for the problem. Beslin O, Nicolas (1997) [15] comparative study has been done on the use of trigonometric set over polynomial with some remarkable advantages. As per the literature survey and of the best knowledge Kobayashi et al. (1988) [4] published the first Ritz-based results for in-plane natural frequencies and mode shapes of rectangular plates. They used a series of product of power functions for the admissible functions. and discussed a limited number of computed results for point-supported isotropic plates for the inplane vibration analysis. Bardell et al. (1996) [5] did their work on isotropic plates and calculated the first six frequency parameters with all edges simply supported, clamped or free using a set of orthogonal polynomials in conjunction with Hermitecubics. Singh and Muhammad (May 2004) [6] developed a modified form of the Ritz Proc. Of the Int. Conf: ARIMPIE-2015 method for the analysis of in-plane modes of isotropic non-rectangular plates. Woodcock et al. (2008) [7] did the first attempt in providing specific information about the influence of angle of orthotropy on the in-plane free motion of rectangular plates. They used the Ritz formulation along with Hamilton principle to study the effect of ply orientation on the in-plane vibrations of composite plates. The natural frequencies were calculated by adopting simple polynomial functions as admissible solutions. Lorenzo Dozio (October 2010) [17] used the Ritz method using a set of trigonometric functions to obtain accurate in-plane modal properties of rectangular plates with arbitrary non-uniform elastic edge restraints. Lorenzo Dozio (October 2010) [3] presented the accurate upper-bound solutions for free in-plane vibrations of singlelayer and symmetrically laminated rectangular composite plates with an arbitrary combination of clamped and free boundary conditions. In-plane natural frequencies and modes shapes are calculated by the Ritz method with a simple, stable and computationally efficient set of trigonometric functions. Influence of fiber orientation, stacking sequence, degree of orthotropy, aspect ratio and boundary conditions upon the in-plane vibration behavior are also discussed. Du et al. (2007) [14] developed an analytical method for the in-plane frequencies and mode shapes of isotropic rectangular plates with classical boundary conditions and elastically restrained edges. It assumes displacement solutions as a linear combination of double Fourier series with supplementary terms such that the assumed solution exactly satisfies both the governing differential equations and the boundary conditions. Gorman (2004a, 2004b, 2005 and 2009) [10, 11, 12, 13] introduced the superposition method as a valuable analytical-type tool to predict in-plane natural frequencies and mode shapes of isotropic and especially orthotropic plates. Highly accurate frequency parameters and shapes of symmetric, anti-symmetric and symmetric-anti-symmetric modes are presented for fully clamped plates with various aspect ratios and orthotropic elastic properties. It provides solutions which satisfy 103 ELK Asia Pacific Journals – Special Issue exactly the governing differential equation throughout the entire domain of the plate. Boundary conditions are satisfied to any desired degree of accuracy by increasing the number of terms in the solution. As the previous review demonstrates, not much approximate solutions are available for free inplane vibration of generally orthotropic multilayered and laminated plates of rectangular platform with any combination of clamped and free boundary conditions. Also, very little research has done to find the accurate in-plane modal properties of square/rectangular plates with uniform elastic edge restraints. In order to achieve the above mentioned goals, the Ritz method has been adopted due to its computational simplicity, wide flexibility, high reliability and computational efficiency. II. Proc. Of the Int. Conf: ARIMPIE-2015 counterclockwise beginning from the edge x = − a /2. For instance, 𝑘1𝑈 and 𝑘1𝑉 are used to indicate the distributed stiffness for the tangential and normal springs, respectively, along the bottom edge of the plate.Noting that, in this formulation, the stiffness for each of the elastic restraints is allowed to vary arbitrarily along an edge, i.e., 𝑘𝛾𝛿 =𝑘𝛾𝛿 (𝜂) for γ = 1, 3 and 𝑘𝛾𝛿 =𝑘𝛾𝛿 (𝜀)for γ = 2,4. Strain And Kinetic Energy The strain energy of the rectangular plate is given by the following expression as per [3]. 2 u 2 v u v A A 2 A 11 22 12 y a / 2 b/ 2 x y x 1 U dx dy 2 2 a / 2 b / 2 u u v v u v 2 A16 x A26 y y x A66 y x FORMULATION Where the In-plane rigidities are given as: Consider a rectangular symmetrically laminated composite plate of dimensions a×b. Where length is a andwidth b lying in the (x, y) plane corresponding to the middle surface of the plate. The plate consists of Nl layers. The material used is assumed to be homogeneous and orthotropic. The thickness of the plate is denoted by h and the kth layer is denoted by hk. The origin of the (x, y) coordinate system is assumed to be located at the plate center and the kth layer is located between the points z = zk and z = zz+1 in the thickness direction. Displacements of the composite plate in the x and y direction are indicated with u=u(x,y,t) and v=v(x, y, t), respectively. An arbitrary combination of clamped (C) and free (F) boundary conditions are considered. Throughout the paper, a four-letter symbolic notation is used for describing the type of boundaries. For example, a CFCF plate has clamped edges at x = ± a/2 and free edges at y = ± b/2. A general support conditions are also considered, which are represented by massless normal and tangential springs along each edge.The stiffness value of each restraining spring is denoted by 𝑘𝛾𝛿 where γ= 1, 2, 3, 4 refers to the plate edge (i.e., location) and δ = U, V refers to the corresponding degree of freedom (i.e., direction).And the plate boundaries are numbered Nl Aij Qij k 1 k Z k 1 Z k The kinetic energy of the rectangular plate is given by the following expression: a / 2 b / 2 u 2 v 2 1 T m0 dx dy 2 a / 2 b / 2 t t Nl Where, m0 k Z k 1 Z k k 1 k is the density of the kth layer. In order to treat these equations taking the nondimensional coordinates as: 2x 2y , a b Consider a harmonic motion with frequency ω, i.e. u , , t u , e iwt ue iwt v , , t v , e iwt veiwt 104 ELK Asia Pacific Journals – Special Issue The maximum strain energy and the maximum kinetic energy stored in the plate during in-plane stretching in a vibratory cycle are calculated as: U max 2 b u 2 u v u u a v 2 A12 2 A16 A11 A22 b a 1 1 1 v v b u v a u v d d 2 A16 2 A26 2 A26 2 1 1 a b 2 2 u v a u b v A66 b A66 a 2 A66 Tmax 1 1 1 m0 ab 2 u 2 v 2 d d 2 4 1 1 The energy functional of the system is determined as: U max Tmax Ritz Trigonometric Set The Ritz approximation method is used to solve the problem and so it is employed by assuming the following solutions for the amplitudes u and v: M Proc. Of the Int. Conf: ARIMPIE-2015 The trigonometric admissible function first proposed by Beslin and Nicolas [13] for flexural vibration of Kirchhoff plates are here applied: m sinam bm sincm d m Similarly, n can be defined accordingly where ξ and m are replaced by η and n, respectively. n sinan bn sincn dn Where the coefficients ai, bi, ci and di are listed in Table 3.1 I 1 2 3 4 >4 ai π/4 π/4 π/4 π/4 π/2(i − 4) bi 3π/4 3π/4 -3π/4 -3π/4 π/2(i − 4) ci π/4 -π/2 π/4 π/2 π/2 di 3π/4 -3π/2 -3π/4 -3π/2 π/2 N u , amnmu nu Table 2.1. coefficients of Ritz trigonometric set m 1 n 1 M N v , bmnmv nv m 1 n 1 Where amn and bmn are unknown coefficients and 𝑢 (𝜉), 𝑣 (𝜉) 𝜑𝑚 𝜑𝑛𝑢(𝜂), 𝜑𝑚 𝑎𝑛𝑑 𝜑𝑛𝑣 (𝜂) are appropriate admissible functions which satisfies at least the geometrical boundary conditions of the problem under consideration. In this related problem, the following displacement boundary conditions apply for each edge. u=v=0 A subset of ϕm(ξ)=pm(x) is plotted in Fig. 2.1 where functions of increasing order are arranged in a matrix-like form. It is seen from the Fig. 1 that the first and third functions ϕ1(ξ) and ϕ3(ξ) allow a non-zero displacement at ξ = −1 and ξ = 1, respectively. Whilesecond and fourth trigonometric functions ϕ2(ξ) and ϕ4(ξ), allow a free slope at the opposite edges ξ = ±1. These can be interpreted as required degrees of freedom at the corner nodes of the plate. : Clamped Edge graph of p(2) graph of p(1) 1 graph of p(3) 1 graph of p(4) 1 0.5 -0.5 -1 0 0.5 x graph of p(9) p(7) -0.5 0 0.5 x graph of p(10) 0 -1 -1 1 -0.5 0 0.5 x graph of p(14) p(14) -0.5 0 x 0.5 1 -0.5 0 0.5 x graph of p(11) -0.5 0 x 0.5 1 1 -0.5 0 0.5 x graph of p(12) 1 -0.5 0 0.5 x graph of p(16) 1 1 -0.5 0 0.5 x graph of p(15) 0 -1 -1 1 1 0 -1 -1 0 0.5 x graph of p(8) 0 -1 -1 1 1 0 -1 -1 -0.5 1 0 -1 -1 1 1 0 -1 -1 1 1 p(11) p(10) 0 0.5 x graph of p(13) 0 0.5 x graph of p(7) 0 -1 -1 1 1 -0.5 -0.5 1 0 -1 -1 1 1 p(13) 0 -1 1 p(15) p(5) p(6) -0.5 0 -1 -1 0 0.5 x graph of p(6) 1 1 -1 -1 -0.5 -0.5 p(8) 1 p(12) 0 0.5 x graph of p(5) p(16) -0.5 0.5 0 -1 v m nu nv n 0.5 0 0 -1 p(9) m , u m p(4) p(3) 0.5 1 Since homogeneous condition is considered, the relation involved for both u and v along one edge, it is assumed as: 0 p(2) u, v not restrained : Free Edge p(1) 0.5 -0.5 0 x 0.5 1 0 -1 -1 -0.5 0 x 0.5 1 105 ELK Asia Pacific Journals – Special Issue Fig. 2.1. The first 16 functions of Ritz trigonometric set The functions ϕ1(η), …, ϕ4(η) are arranged in a similar fashion for η = ±1. As such, the first four functions ϕ1, …,ϕ4 permit one to easily satisfy free and clamped boundary conditions by selecting a proper combination among them. The four combinations of boundary conditions are considered in this work are tabulated in Table 2.1 For case m, n > 4 all trigonometric functions have zero deflection and slope at both ends ξ, η = ±1 and the order of a function is seen related to the number of oscillations inside the domain.This offers a great numerical stability because of its well-conditioned mass and stiffness matrices are obtained here, even considering very high order functions (m, n ≫ 1), i.e. M, N can be taken very large and no special attention to round-off errors is required. A further attractive property of the present trigonometric set has in its simple algebra and calculus. First, a very low number of operations are needed contrary to other Ritz functions such as polynomials to manage them and this number does not increase with order. Second, all integrals involved in calculations of mass and stiffness matrices can be obtained analytically without restoring to recursive formulas. Last, using simple trigonometric identities, it can be shown that a huge number of elements of such integrals are identically zero. As a consequence, the mass and stiffness matrices tend to be highly sparse. , even when it is large can be solved by very efficient method using MATLAB. Ritz approximations for u and v, is solved numerically for the resulting sparse eigenvalue problem in a very efficient way using, iterative projection methods of Arnoldi type. An algorithmic variant of the Arnoldi process called the Implicitly Restarted Arnoldi method is used here as implemented in MATLAB via the builtin eigs function. Boundary Condition (I) Proc. Of the Int. Conf: ARIMPIE-2015 BOUNDARY Φ1 Φ2 Φ3 Φ4 CONDITIONS FF FC CF CC Table 2.2. Combination of first four functions in the trigonometric set to satisfy the related boundary condition Combinations of first four functions are to satisfy the related boundary condition. Bullets in a row indicate which functions are retained in the final set. Boundary Condition (II) Classical boundary conditions can be easily recovered by accordingly setting the values of the related springs. A free condition along one edge, designated by the symbol F, is obtained by setting to zero both the corresponding normal and tangential spring. Infinitely large value of both sets of springs allows simulating an essentially clamped (C) edge. Two distinct sets of simple support boundary conditions are physically realizable in the case of in-plane vibration analysis of rectangular plates. The first type of simple support condition can be obtained by specifying infinite stiffness for the tangential springs and zero stiffness for the normal springs. Zero and infinite values for the tangential and normal springs, respectively, allow simulating the S2-type boundary condition. In a similar fashion, three types of elastically restrained edges, indicated by the symbols E1 , E 2 and E12 , are here introduced. E1 -type edges are characterized by elastically restrained displacement parallel to the edge and free displacement normal to the edge. On the contrary, support type E 2 allows free parallel displacement along the edge and elastically restrained displacement normal to the edge. When both normal and parallel displacements along the edge are elastically restrained, the edge 2 support is denoted by E1 . 106 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Coupled Eigenvalue Problem (I) The coefficient amnand bmn can be obtained by taking the extremum of the energy functional π is given as: After putting gives the following coupled eigenvalue equations: K uu mnrs rs K vu mnrs rs N r 1 s 1 M N r 1 s 1 01 10 12 mr ns a 00 11 b 11 00 uu 10 01 01 10 K mnrs A22 I mr I ns A66 I mr I ns A26 I mr I ns I mr I ns b a b a vu K mnrs A12 I mr01 I ns10 A16 I mr11 I ns00 A26 I mr00 I ns11 A66 I mr10 I ns01 a b a b b a uu K mnrs A22 I mr00 I ns11 A66 I mr11 I ns00 A26 I mr10 I ns01 I mr01 I ns10 E mr 1 J ns1V E mr1 J ns3V J mr2V E ns 1 J mr4V E ns1 b a 2 2 m0 ab 00 00 I mr I ns 4 J mr k m r d 1 1 J ns k n s d 1 In which d m d r d d d 1 When elastic boundaries are considered, coupled eigenvalue equations will be formulated as simple elemental equation and few expressions are modified as and rest will remain like that only: 1 m ab 00 00 0 I mr I ns 4 1 vv a K mnrs brs 2 M mnrsbrs 0 Where b 11 00 a 10 01 A I I A16 I mr I ns A26 I mr00 I ns11 A66 I mr I ns a b I mr N M mnrs b 11 00 a 00 11 uv 10 01 01 10 K mnrs A12 I mr I ns A16 I mr I ns A26 I mr I ns A66 I mr I ns a b M mnrs vu mnrs rs M vv a K mnrs brs 2 M mnrsbrs 0 b 11 00 a 00 11 uu 10 01 01 10 K mnrs A11 I mr I ns A66 I mr I ns A16 I mr I ns I mr I ns a b K K r 1 s 1 uv a K mnrs brs 2 M mnrsars 0 b a b a uu K mnrs A11 I mr11 I ns00 A66 I mr00 I ns11 A16 I mr10 I ns01 I mr01 I ns10 E mr 1 J ns1U E mr1 J ns3U J mr2U E ns 1 J mr4U E ns1 a b 2 2 b 11 00 a 00 11 uv 10 01 01 10 K mnrs A12 I mr I ns A16 I mr I ns A26 I mr I ns A66 I mr I ns a b uv a K mnrs brs 2 M mnrsars 0 The elements of the plate stiffness and mass matrices are as follow: vu mnrs uu mnrs rs N r 1 s 1 0, 0 a mn bmn M K M I ns 1 d n d s d d d 1 are the integrals of the derivatives of order α and β of the trigonometric functions. Coupled Eigenvalue Problem (II) New coupled eigenvalue equations after considering elastic boundary are following 0 Emr m 0 r 0 d 0 Ens n 0 s 0 d J ns k I ij00 In simplified matrix form for the MATLAB implementation the coupled eigenvalue equations can be written as: K a K b M a 0 uu mnrs uv mnrs 2 mnrs K a K b M b 0 vu mnrs vv mnrs 2 mnrs 107 ELK Asia Pacific Journals – Special Issue Results are obtained by adopting a square selection strategy, where the same number of terms M = N is used in the series expansion, with no regard to symmetry. III. RESULTS In this section,several plate problems involving different combinations of boundary conditions and complicating factors have been solved by TRM (Trigonometric Ritz Method) and analysis has been done to focus on single-layer composite plates made of an isotropic/orthotropic material. First, to check the accuracy of the applied method validation of the results are presented in the tabular form. After that, this method is more expended to the next level another kind of elastic boundary conditions are considered and parametric studies are done by using data in tabular form and graphs are also drawn to analyze it better. Validation of the method (Degree) 0 15 30 45 FIRST MODE SECOND MODE FIRST MODE SECOND MODE FIRST MODE SECOND MODE FIRST MODE considered for the comparison of the results and validity of the work. Elastic Modulus (E1) (N/𝒎𝟐 ) Passio n’s Ratio (v) Thicknes s(h) (mm) Leng th (a) (m) Densi ty (rho) (Kg/ 𝒎𝟑 ) 70e9 0.3 2.5 1 2700 Table 3.1. Material properties and dimensions of the composite plate For the sake of comparison with data provided in Ref.3, an orthotropic material with the following properties is utilized in Table 3.1. v12v21 v 2 , G12 For the sake of comparison with the previous references and validity of the work few works are done on the single layer composite plates. First a square single-layered composite plate (i.e. b/a=1) is taken into consideration where ratio of elastic modulus is E2/E1 = 1.5 & 2.5. The angle of orthotropyθ in the following tabulated results will vary from 0° to 90° with 15° increments. The CCCC and FFFF boundary conditions are Ang Proc. Of the Int. Conf: ARIMPIE-2015 FFFF(b/a=1) E2/E1=1.5 Ref.3 Present 1.265 E1 E 2 2 1 v12v 21 The properties used to calculate in-plane nondimensional frequency parameter is given in the Table 3.1. Results are presented in the form of the non-dimensional in-planefrequency parameter is given as, a 1 v12v21 2 E1 Error (%) FFFF(b/a=1) E2/E1=2.5 Ref.3 Present Error (%) 1.3473 6.50592885 1.2906 1.4588 13.032698 1.2831 1.4387 12.1268802 1.4529 1.6924 16.4842728 1.2736 1.3164 3.36055276 1.3103 1.3762 5.02938258 1.2764 1.455 13.9924788 1.3929 1.7414 25.019743 1.2655 1.2717 0.48992493 1.3562 1.2697 6.37811532 1.2943 1.4705 13.6135363 1.3586 1.7854 31.4146916 1.2609 1.2532 0.61067491 1.345 1.232 8.40148699 108 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 SECOND 1.3076 1.4745 12.7638422 1.3904 1.795 MODE FIRST 1.2655 1.2717 0.48992493 1.3562 1.2697 MODE 60 SECOND 1.2943 1.4705 13.6135363 1.3586 1.7854 MODE FIRST 1.2736 1.3164 3.36055276 1.3103 1.3762 MODE 75 SECOND 1.2764 1.455 13.9924788 1.3929 1.7414 MODE FIRST 1.265 1.3473 6.50592885 1.2906 1.4588 MODE 90 SECOND 1.2831 1.4387 12.1268802 1.4529 1.6924 MODE Table 3.2. Non-dimensional in-plane frequency parameter of composite FFFF plates. Angle (Degree) FIRST MODE 0 SECOND MODE FIRST MODE 15 SECOND MODE FIRST MODE 30 SECOND MODE FIRST MODE 45 SECOND MODE FIRST MODE 60 SECOND MODE FIRST 75 MODE SECOND 29.0995397 6.37811532 31.4146916 5.02938258 25.019743 13.032698 16.4842728 single-layer CCCC(b/a=1) CCCC(b/a=1) E2/E1=1.5 E2/E1=2.5 Ref.3 Present Error (%) Ref.3 1.8329 1.84836 0.843472093 2.1175 1.96334 1.8558 1.80412 2.114 1.98584 1.8418 1.74136 2.1066 2.0052 1.8449 1.71556 2.1028 2.0092 1.8418 1.74136 2.1066 2.0052 1.8558 1.80412 2.114 1.98584 7.280283353 2.784782843 -6.06244087 5.453360843 4.813443463 7.010678086 4.451207913 5.453360843 4.813443463 2.784782843 -6.06244087 Present Error (%) 1.9156 2.0064 4.74002923 2.6132 2.3008 1.9215 1.8879 2.6088 2.3672 1.9341 1.93912 0.25955225 2.5998 2.4178 -7.0005385 1.9408 1.88736 2.5951 2.4244 -6.5777812 1.9341 1.93912 0.25955225 2.5998 2.4178 -7.0005385 1.9215 1.8879 2.6088 2.3672 11.9546916 1.74863388 9.26096289 2.75350371 1.74863388 - 109 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 MODE FIRST MODE 90 SECOND MODE 9.26096289 1.8329 1.84836 2.1175 1.96334 0.843472093 7.280283353 1.9156 2.0064 2.6132 2.3008 4.74002923 11.9546916 Table 3.3. Non-dimensional in-plane frequency parameter of single-layer composite CCCC plates. Further by using above properties and TRM methodology in various results for in-plane non-dimensional frequency is calculated. For the square plate present results are compared with Ref.3 with stiffness ratio E2/E1 = 1.5 & 2.5. Computed eigenvalues are presented in two tables according to the combination of clamped and free edge supports. For the FFFF condition this is depicted in Table 3.2 and for CCCC condition it is presented in Table 3.3. For the isotropic plate where E2/E1=1, are considered for the study where elastic boundaries are applied and various effects are tabulated in present work. For the analysis the current approach is E1 E1 E1 E1 plate with V V V V edge stiffness k 0 (i.e. k1 k2 k3 k4 k0 investigated for a square U and k1 k 2U k 3U k 4U 0 ). The first four in-plane dimensionless frequency From these tables, the influence of aspect ratio, material stiffness ratio, and angle of orthotropy and boundary conditions on the in-plane vibration of single-layer generally orthotropic plates may be observed. First, it is noted that, with all the other parameters kept fixed, the frequency values decrease with increasing number of free edges. Moreover, for each boundary support condition, higher eigenvalues are obtained when the plate has higher stiffness ratio E2/E1 regardless of aspect ratio and angle of orthotropy. For both completely free and completely fixed square plates, i.e., b/a = 1.0 i.e. Table 3. Due to symmetry, all the frequencies are symmetric with respect to 45° orientation. So this can be seen from both the Table 3&4; the present result is very much close to the previous work. This gives the validity of the method and can be used for the further parametric study. Although in FFFF results for 2nd mode is varying as compared to other results but this can be treated in range. Rest all results are quite friendly compared to the previous one. Numerical study on isotropic plate parameters a 1 v12v21 are shown 2 E1 in Table 4.4 and Table 4.5 for two finite values of the dimensionless elastic edge stiffness: k* = k0 (a/2)(1 − ν2)/E. From using data of Table 4.4 & 4.5 different kind of elastic edges (E1, E2, E12) and few values of the dimensionless elastic edge stiffness, k=1, 10−2 , 10−4 , 10−6 are considered. It is observed from the calculated nondimensional in-plane frequency parameter that in the isotropic plate with plate dimension aspect ratio b/a=1 i.e. a square plate, the effects of E1elastic edge is same as the E2-elastic edge conditions because of equal length and breadth of the plate. But when rectangular plate is considered where aspect ratio b/a=2 is taken for study, there is some variations in the effects of E1-elastic edge and E2-elastic edge. While considering E12-elastic edge conditions, this has relatively large value of non-dimensional frequency parameter compared to E1- and E2edge. 110 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 E1 support (b/a=1) 4th Mode 3.2915 3.215 rd 3 Mode 5.125 4.4504 3.2143 3.2143 2nd Mode 3.2143 3.2143 1.2601 1.2601 st 1 Mode 1.2601 1.2601 1.136 1.2588 E2 support (b/a=1) 4th Mode 3.2915 3.8244 rd 3 Mode 5.125 4.4504 3.2143 3.3126 2nd Mode 3.2143 3.2143 1.2601 1.4547 1st Mode 1.2601 1.2601 1.136 1.3154 E12 support (b/a=1) 2nd Mode 9.21 8.434 7.4011 8.161 1st Mode 5.125 4.2986 3.8803 4.821 Table 4.4. Non-dimensional in-plane frequency parameter of isotropic EEEE plates with aspect ratio b/a=1 E1 support (b/a=2) 4th Mode rd 6.482 nd 2.1794 0.92926 3 Mode 2 Mode st 1 Mode E2 support (b/a=2) 4th Mode 2.8329 2.7547 2.8329 2.1794 2.1794 0.92926 0.61767 0.92926 0.61767 0.92926 0.73413 2.754 2.7953 rd 6.517 2.268 2.268 2.5276 nd 2.754 0.81092 0.81092 1.0852 0.73537 0.73537 0.73537 0.80178 8.517 7.8621 2.8721 6.7079 3 Mode 2 Mode st 1 Mode E12 support (b/a=2) 2nd Mode st 1 Mode 4.482 4.6049 2.6009 3.9778 Table 4.5. Non-dimensional in-plane frequency parameter of isotropic EEEE plates with aspect ratio b/a=2. For the orthotropic plates where elastic modulus have different value in different directions, all studies are done by taking stiffness ratio E1/E2 = 2. All three previously discussed elastic edge conditions are considered and different values of the dimensionless elastic edge stiffness, k=1, 10−1 , 10−3 , 10−5are also considered. 111 Proc. Of the Int. Conf: ARIMPIE-2015 E1/E2 = 2, b/a=1, 1st Mode, Support- E1 1.5 1.4 1.3 1.2 1.1 0 20 40 60 80 100 Angle (degree) k=1 k=1e-1 k=1e-3 Non-dimensional frequency paprmeter Non-dimensional frequency paprmeter ELK Asia Pacific Journals – Special Issue E1/E2 = 2, b/a=1, 2nd Mode, Support-E1 5 4 3 2 1 0 0 20 40 60 80 100 Angle (degree) k=1e-5 K=1 K=1e-1 k=1e-3 k=1e-5 Figure 4.3. Variation of the first two frequency parameter and dimensionless elastic edge 𝐸1 square 𝐸 composite plate with 𝐸1 = 2 with respect to degree of orthotropy E1/E2 = 2, b/a=1, 1st Mode, Support- E2 1.4 1.35 1.3 1.25 1.2 1.15 0 20 40 60 80 100 Angle (degree) K=1 k=1e-1 k=1e-3 k=1e-5 Non-dimensional frequency paprmeter Non-dimensional frequency paprmeter 2 E1/E2 = 2, b/a=1, 2nd Mode, Support- E2 4 3.5 3 2.5 2 1.5 1 0.5 0 0 20 40 60 80 100 Angle (degree) k=1 k=1e-1 k=1e-3 k=1e-5 Figure 4.4. Variation of the first two frequency parameter and dimensionless elastic edge 𝐸2 𝐸 square composite plate with 𝐸1 = 2 with respect to degree of orthotropy 2 112 Proc. Of the Int. Conf: ARIMPIE-2015 E1/E2 = 2, b/a=1, 1st Mode, Support- E12 20 15 10 5 0 0 20 40 60 80 100 Angle (degree) k=1 k=1e-1 k=1e-3 Non-dimensional frequency paprmeter Non-dimensional frequency paprmeter ELK Asia Pacific Journals – Special Issue E1/E2 = 2, b/a=1, 2nd Mode, Support- E12 20 15 10 5 0 0 20 40 60 80 100 Angle (degree) k=1e-5 k=1 k=1e-1 k=1e-3 k=1e-5 Figure 4.5. Variation of the first two frequency parameter and dimensionless elastic edge 𝐸12 𝐸 square composite plate with 𝐸1 = 2 with respect to degree of orthotropy E1/E2 = 2, b/a=2, 1st Mode, Support- E1 1.2 1 0.8 0.6 0.4 0.2 0 0 20 40 60 80 100 Angle (degree) k=1 k=1e-1 k=1e-3 k=1e-5 Non-dimensional frequency paprmeter Non-dimensional frequency paprmeter 2 E1/E2 = 2, b/a=2, 2nd Mode, Support- E1 3 2.5 2 1.5 1 0.5 0 0 20 40 60 80 100 Angle (degree) K=1 k=1e-1 k=1e-3 k=1e-5 Figure 4.6. Variation of the first two frequency parameter and dimensionless elastic edge 𝐸1 𝐸 rectangular composite plate with 𝐸1 = 2 with respect to degree of orthotropy 2 113 Proc. Of the Int. Conf: ARIMPIE-2015 E1/E2 = 2, b/a=2, 1st Mode, Support- E2 Non-dimensional frequency paprmeter Non-dimensional frequency paprmeter ELK Asia Pacific Journals – Special Issue 0.84 0.82 0.8 0.78 0.76 0.74 0 20 40 60 80 E1/E2 = 2, b/a=2, 2nd Mode, Support- E2 4 3 2 1 0 0 100 20 k=1e-1 60 80 100 Angle (degree) Angle (degree) K=1 40 k=1e-3 k=1e-5 k=1 k=10e-2 k=10e-4 k=10e-6 Figure 4.7. Variation of the first two frequency parameter and dimensionless elastic edge 𝐸2 𝐸1 𝐸2 = 2 with respect to degree of orthotropy E1/E2 = 2, b/a=2, 1st Mode, Support- E12 15 10 5 0 0 20 40 60 80 100 Non-dimensional frequency paprmeter Non-dimensional frequency paprmeter rectangular composite plate with E1/E2 = 2, b/a=2, 2nd Mode, Support- E12 15 10 5 0 0 Angle (degree) k=1 k=1e-1 k=1e-3 50 100 Angle (degree) k=1e-5 k=1 k=1e-1 k=1e-3 k=1e-5 Figure 4.8. Variation of the first two frequency parameter and dimensionless elastic edge 𝐸12 𝐸 rectangular composite plate with 𝐸1 = 2 with respect to degree of orthotropy 2 114 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Numerical study on multi-layer composite plate FREQUENCY PARAMETER b/a=1 (90/0)2S 4 th FFFF CFCF 3.0535 2.9378 Mode rd 3 5.6168 2.4157 2.3160 Mode nd 2 4.4042 1.1154 .96926 Mode 1 st 1.51898 .99699 .86661 Mode (90/02/90)S 4th 1.3698 3.0535 7.2902 2.4157 5.3237 1.1154 3.0651 .99699 2.7405 Mode 3rd 5.6168 Mode 2nd 4.4042 Mode 1st 1.51898 Mode b/a=2 (90/0)2S 4th 1.3698 2.0004 1.9329 1.9888 1.9041 .85628 .74678 Mode 3rd 3.7186 Mode 2nd 1 1.18066 .60198 .52013 Mode (90/02/90)S 4th 0.81118 2.0004 6.1124 1.9888 4.0212 .85628 2.3615 .60198 1.6448 Mode 3rd 3.7186 Mode 2nd 3.6132 Mode 1st Mode IV. CONCLUSIONS This paper has presented a reasonably comprehensive set of numerical results for inplane free motion of single-layer generally orthotropic and symmetrically laminated rectangular plates with an arbitrary combination of clamped and free boundaries. An analysis has done on in-plane vibration analysis of rectangular plates with uniform elastically restrained edges. Accurate analytical-type solutions have been obtained by a highly stable trigonometric set of trial functions in the Ritz method. Following observations and conclusions we made on the study of In-plane vibrations. 3.6132 Mode st CCCC After validating the results for the single-layer composite plates, work is next extended to multi-layer composite plates. Two kinds of different laminates (90/0)2s and 90/0/0/90)s are taken. Both are symmetric in nature and each lamina thickness is 2.5 mm. Three different kind of basic boundary conditions are considered, FFFF, CFCF and CCCC. This work is done for aspect ratio, b/a=1, 2. The non-dimensional frequencies for four modes are tabulated in the following Table 4.1. 1.18066 0.81118 Table 4.1: Non-dimensional in-plane frequency parameter of multi-layer composite plates. 1. First, it is noted that, with all the other parameters like orthotropic angle, aspect ratio of the plate, material stiffness ratio kept fixed, the frequency values decrease with increasing number of free edges. 2. Moreover, for each boundary support condition, higher eigenvalues are obtained when the plate has higher stiffness ratio E2/E1 regardless of aspect ratio and angle of orthotropy. 3. For square composite plates, the effects of E1 and E 2 are same. While for rectangular plates E1 and E 2 elastic edge have different effects on the In-plane frequency. 4. Calculated non-dimensional In-plane frequency parameter on the effect of E1 elastic edge and E 2 elastic edge are similar and value sometime overlaps each other. This possibility is much for the 1st mode 115 ELK Asia Pacific Journals – Special Issue than the 2nd mode and so on while E12 elastic edge offers large value of nondimensional In-plane frequency. 5. It is observed that dimensionless elastic edge stiffness value (k*) has significant effects on the non-dimensional frequency parameter. As the value of dimensionless elastic edge value is increasing it is shifted towards fully restrained edges. 6. Angle of orthotropy has varied results for different cases studied. There is no such similar pattern. But boundary condition when keeping same and other parameters like material stiffness ratio and dimensionless elastic edge stiffness value varies and values of non-dimensional frequency parameter changes but follows similar pattern can be seen in the graphs. V. REFERENCES [1] D.J. Gorman, Exact solutions for the free inplane vibration of rectangular plates with two opposite edges simply supported. J Sound Vib, 294 (2006), pp. 131–161. [2] Y.F. Xing, B. Liu, Exact solutions for the free in-plane vibrations of rectangular plates. Int J MechSci, 51 (2009), pp. 246–255. [3] Lorenzo Dozio, In-plane free vibrations of single-layer and symmetrically laminated rectangular composite plates. Composite Structures, Volume 93, Issue 7, June 2011, Pages 1787–1800 Proc. Of the Int. Conf: ARIMPIE-2015 vibration of single-layer composite plates. J Sound Vib, 312 (2008), pp. 94–108 [8] G. Wang, N.M. Wereley, Free in-plane vibration of rectangular plates. AIAA J, 40 (2002), pp. 953–959 [9] D.J. Gorman, Vibration analysis of plates by the superposition method. World Scientific, Singapore (1999) [10] D.J. Gorman, Free in-plane vibration analysis of rectangular plates by the method of superposition.J Sound Vib, 272 (2004), pp. 831– 851 [11] D.J. Gorman, Accurate analytical type solutions for the free in-plane vibration of clamped and simply supported rectangular plates. J Sound Vib, 276 (2004), pp. 311–333 [12] D.J. Gorman, Free in-plane vibration analysis of rectangular plates with elastic support normal to the boundaries. J Sound Vib, 285 (2005), pp. 941–966 [13] D.J. Gorman, Accurate in-plane free vibration analysis of rectangular orthotropic plates. J Sound Vib, 323 (2009), pp. 426–443 [15] J. Du, W.L. Li, G. Jin, T. Yang, Z. Liu, An analytical method for the in-plane vibration analysis of rectangular plates with elastically restrained edges.J Sound Vib, 306 (2007), pp. 908–927 [4] Y. Kobayashi, G. Yamada, S. Honma, Inplane vibration of point-supported rectangular plates.J Sound Vib, 126 (1988), pp. 545–549 [16] O. Beslin, J. Nicolas, A hierarchical functions set for predicting very high order plate bending modes with any boundary conditions. J Sound Vib, 202 (1997), pp. 633–655 [5] N.S. Bardell, R.S. Langley, J.M. Dunsdon , On the free in-plane vibration of isotropic rectangular plates. J Sound Vib, 191 (1996), pp. 459–467 [17] Dozio L, On the use of the trigonometric Ritz method for general vibration analysis of rectangular Kirchhoff plates. Thin Wall Structure 2011; pp49:129–44. [6] A.V. Singh, T. Muhammad, Free in-plane vibration of isotropic non-rectangular plates. J Sound Vib, 273 (2004), pp. 219–231 [18] L. Dozio, Free in-plane vibration analysis of rectangular plates with arbitrary elastic boundaries. Mech Res Commun, 37 (2010), pp. 627–635. [7] R.L. Woodcock, R.B. Bhat, I.G. Stiharu, Effect of ply orientation on the in-plane 116 ELK Asia Pacific Journals – Special Issue 20. EXPERIMENTAL INVESTIGATION OF COMPARISION OF AIR COOLED AND WATER COOLED CONDENSER ATTACHED WITH COOLING TOWER Gourav Roy1* ,Taliv Hussain2, Rahul Wandra3 Department of Mechanical Engineering, Lovely Professional University Phagwara, Punjab (India) -144402 Email:
[email protected] Abstract-This paper presents an experimental investigation of comparison of air cooled condenser and water cooled condenser with cooling tower. Water cooled condenser is attached to cooling tower in vapour compression refrigeration system. The VCRS system is made with the component of refrigerator to check the performance of air cooled and water cooled condenser with cooling tower. Data is noted after steady state condition is achieved in the system and the properties of refrigerant (R143a) and air remained constant after (20min). Experimental test are performed at two ambient air temperatures 27°C and 30°C.At 27°C ambient temperature the COP of air cooled condenser is 4.59 which is increases up to 4.817 when VCRS attached with cooling tower. Similarly at 30°C ambient temperature the COP varies from 4.49 to 4.58 when we move from air cooled condenser to water cooled condenser attached with cooling tower. There is an increase in the COP of VCRS attached with cooling tower as compare to air cooled condenser. Keywords-Air cooled condenser, Water cooled condenser, vapour compression refrigeration system, evaporative cooling pad. Nomenclature-COP Coefficient of performance h1 Enthalpy of refrigerant at inlet of compressor in kj/kg h2 Enthalpy of refrigerant at exit of compressor in kj/kg h3 Enthalpy of refrigerant at exit of the condenser kj/kg h4 Enthalpy of refrigerant at entry of evaporator in kj/kg Proc. Of the Int. Conf: ARIMPIE-2015 mref Mass flow rate of refrigerant Qr Cooling effect Wc Compressor work T1 Suction temperature of refrigerant into the compressor T2 Discharge temperature of refrigerant into the compressor T3 Condenser outlet temperature of refrigerant T4 Outlet temperature of refrigerant from capillary tube I Inlet current V Inlet voltage I. INTRODUCTION The key to nation building lies in the optimum and proper use of energy and capital. Research on refrigeration and air conditioning has facilitated the correction of human vision; it has given us vast technology such as VCRS, VARS, psychometry etc .India Scientific Policy Resolution (SPR) of 1958 emphasis use of the scientific approach toward development of nation building which remains valid even today. In refrigeration and air conditioning domain, several scientists have contributed greatly to our understanding of VCRS. During 1834 the first mechanical device cooling system have been develop later it become vapour compressor. The major objective of our experiment involved compare between the air cooled and water cooled condenser attached with cooling tower. Water cooled condenser has some special advantage in order to increase the performance as compared to air condenser. We can increase the COP of system by attached with it cooling tower. By taking two different ambient temperature 27°C and 30°C,calculate following parameter such discharge pressure, suction pressure, Condenser Outlet Temperature, Condenser Inlet Temperature etc. As we increase the ambient temperature COP get decrease for air condenser as well as water condenser with cooling tower .For air cooled condenser at 27°C and 30°C, COP is 4.59 and 4.49.Similarly for water cooled condenser at 27°C and 30°C, COP is 4.817 and 4.58 respectively. II. LITERATURE SURVEY 117 ELK Asia Pacific Journals – Special Issue S.S. Hu, B.J. Huang et al. [1] conducted an experimental investigation on a split air conditioner having water cooled condenser. They developed a simple water-cooled air conditioner utilizing a cooling tower with cellulose pad filling material to cool the water for condensing operation. The experimental investigation verified that the water-cooled condenser and cooling tower results in decreasing the power consumption of the compressor. Sreejith K et al. [2] Heat can be recovered by using the water-cooled condenser and the system can work as a waste heat recovery unit. The recovered heat from the condenser can be used for bathing, cleaning, laundry, dish washing etc. The modified system can be used both as a refrigerator and also as a water heater. Therefore by retrofitting a water cooled condenser it produce hot water and even reduce the utility bill of a small family. In this system the watercooled condenser is designed as a tube in tube heat exchanger of overall length of 1m. It consists of an inlet for the cooling water and an exit for collecting the hot water. The hot water can be used instantly or it can be stored in a thermal storage tank for later use. Adarsh Mohan Dixit, Aditya Desai, Akshay Vyas et al.[3] They made setup of 1.5 ton air conditioner was constructed and tested in the present study. The experimental results show the coefficient of performance (COP) reaches 8.03 that are higher than the standard value (5.98) of those conventional residential split air conditioners. Kulkarni and Rajput [4] theoretically analyzed the performance of indirect-direct two stages cooler with cellulose and aspen media in direct stage. They selected the most frequently occurring inlet condition of 39.9 0C DBT and 32.8 % RH for the analysis. The saturation efficiency ranged from 121.5 to 106.7 % for two stages cooler. III EXPERIMENTAL SETUP Proc. Of the Int. Conf: ARIMPIE-2015 cellulose pad are used in cooling tower cool the warm water discharged from the condenser and feed the cooled water back to the condenser. The COP varies from 27°C to 30°C as the ambient temperature increase. Initially our setup is air cooled condenser .Through with the help of external fan air is circulated to air condenser in VCRS system. Air passes horizontally through condenser and takes latent heat from the refrigerant which further helps to condense the refrigerant. Our experiment setup consists of single stage vapour compression system which contains different components parts such as expansion device, compressor, evaporator and evaporative cooled condenser. The compressor of volume (cc) 4.5 are used to increase the pressure and temperature of refrigerant (R134a).Here the capillary tube is used, made up of a copper tube of very small diameter. Capillary tube used as expansion device. The evaporator is used to reduce the pressure, dissipating heat and making liquid refrigerant to much cooler. Evaporator used in this experiment setup is tube and fin type. Fig.1 Air Cooled Condenser After calculated different parameter by using air condenser, now condenser is dipped in water tank which is attached to cooling tower as shown in (Fig.2). In the present work we have concentrated toward the comparison of air cooled and water cooled which is attached to cooling tower. Here 118 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Fig.3 Cellulose pad within cooling tower IV. EXPERIMENT DISCUSSION PARAMET ERS UNIT Fig.2 Water Cooled condenser with cooling tower Different measuring devices are used in this experiment setup such as Digital Thermometer TPM-10, which gives the temperature at various points within the system. Pressure gauge is also used; first pressure gauge measures the suction pressure before the compressor and second pressure gauge measure the discharge pressure after the compressor. Similarly ammeter and voltmeter are used to measure the current and voltage to input to the system. A cellulose pad of 2 inch thickness is installed in the cooling tower. The main function of cellulose pad is to provide the evaporative action by transferring the latent heat of water coming from water dip condenser. RESULT AND Air Cooled condens er Water cooled condense r with cooling tower At 27 °C At 30 °C At 27 °C At 30 °C Suction Pressure Psi 12 12 8 8 Discharge Pressure Psi 21 5 21 5 150 15 0 Condenser Inlet Temperature Degree Celsius °C 40. 1 42. 3 37. 2 39. 4 Condenser Outlet Temperature Degree Celsius °C 36. 2 38. 4 28. 9 31. 1 Compressor Inlet Temperature Degree Celsius °C 9.1 11. 1 19. 1 21. 1 Compressor Outlet Temperature Degree Celsius °C 44. 4 46. 4 40. 1 42. 1 Evaporator Inlet Temperature Degree Celsius °C 23. 4 22. 7 22. 5 21. 8 Evaporator Outlet Temperature Degree Celsius °C 13. 1 12. 4 17. 6 16. 9 urrent Ampere 1.2 A 1.2 1.2 1.2 119 ELK Asia Pacific Journals – Special Issue Voltage Proc. Of the Int. Conf: ARIMPIE-2015 Volt V 20 0 20 0 200 20 0 Dry Bulb Degree Temperature Celsius °C 27 27 25 25 Wet Bulb Degree Temperature Celsius °C 20 20 15 15 Fig 4: Pressure-Enthalpy diagram for air cooled condenser and water cooled with cooling tower at an ambient temperature 27°C Table 1: Result of the experiment of air cooled condenser and water cooled condenser with cooling tower The above table at an ambient temperature 27 °C and 30 °C respectively. Our experiment was carried out in two consequent steps. In initial step we have taken air cooled condenser and calculated COP. Further that we dipped the condenser in water and condenser is attached with cooling tower. While performing the experiment refrigerant and air remained constant in order to achieve steady state also current and voltage is constant for both the ambient temperature 27°C and 30°C in air cooled condenser and water cooled condenser with cooling tower. Fig 5: Pressure-Enthalpy diagram for air cooled condenser and water cooled with cooling tower at an ambient temperature 30°C V. CALCULATION AND RESULT While performing the experiment, the result obtained. Based on this result thermodynamic properties of refrigerant R134a are obtained at the different point of the system. In order to calculate the enthalpy, using the P-h chart of the refrigerant R134a and we are getting different parameter at air cooled condenser and water cooled condenser attached with cooling tower. a. Compressor Work Wc = V * I = mref* (h2 – h1) b. Mass flow rate of refrigerant mref c. Cooling effect produced Qr=mref* (h1 –h4) d. COP = Where, h1 = enthalpy of refrigerant at inlet of compressor in kj/kg (1) h2 = enthalpy of refrigerant at exit of compressor in kj/kg (2) 120 ELK Asia Pacific Journals – Special Issue h3 = enthalpy of refrigerant at exit of the condenser kj/kg (3) h4 = enthalpy of refrigerant at entry of evaporator in kj/kg (4) Parameter COP Air Cooled Water condenser Cooled condenser 27 °C 30 °C 27 °C 30 °C 4.59 4.49 4.817 4.58 Table 2: Result of the experiment at ambient air temperature 27°C and 30°C Proc. Of the Int. Conf: ARIMPIE-2015 after taking latent heat from refrigerant with the help of pump it circulate to cooling tower where it became to cooled down and again circulate to condenser. From(graph 1) which shown that the COP of system decrease as the ambient temperature goes on increase. The test result shown that at an ambient temperature 27°C when we move from air cooled condenser to water cooled condenser with cooing tower there is 4.94% COP gain. Similarly at an ambient temperature 30°C there is 2% rise in COP as we move from air condenser to water condenser with cooling tower. REFERENCES [1] S.S. Hu, B.J. Huang, “Study of a high efficiency residential split water-cooled air conditioner”, Applied Thermal Engineering 25 (2005) 1599–1613 [2] Experimental Investigation of A Domestic Refrigerator Having water cooled condenser using various compressor oils, Sreejith K, Assistant Professor, Dept.Of Mechanical. [3] Improving efficiency of air conditioner by cellulose pad/International journal of engineering science & humanities ISSN 22503552 Graph 1: cop variation with ambient temperature [4] Kulkarni R.K., Rajput S.P.S.,(2011) : Theoretical Performance Analysis of IndirectDirect Evaporative Cooler in Hot and Dry Climates, International Journal of Engineering Science and Technology, 3, pp.1239-1251. From the above graph it is clear shown that as the ambient temperature increase COP of system in both cases 27°C and 30°C decrease .AS the COP decrease cooling capacity of system is also decrease. But COP in water cooled condenser with cooling tower have higher COP than simple air condenser in both ambient temperature 27°C and 30°C. VI CONCLUSION This air cooled condenser design is very simple and easy to use. We used same condenser and dipped in water it became water cooled condenser, further it is attached to normal cooling tower. The hot water from condenser 121 ELK Asia Pacific Journals – Special Issue 21. COMPUTATIONAL FLUID FLOW ANALYSIS OF HIGH SPEED CRYOGENIC TURBINE USING CFX Sushant Upadhyay, Shreya Srivastava, Siddharth Sagar, Surabhi Singh, Hitesh Dimri Department of Mechanical Engineering, JSS Academy of Technical Education, Noida, Uttar Pradesh, India
[email protected] Abstract— A turbo expander also referred as an expansion turbine, is a centrifugal or axial flow turbine through which a high pressure gas is expanded to produce work that is often used to drive a compressor. The low pressure exhaust gas from the turbine is at a very low temperature that is 120K or less depending upon the operating conditions. It is widely used as sources of refrigeration in industrial processes and liquefaction of gases such as oxygen, nitrogen, helium, argon and krypton. A cryogenic system needs many components, compressor, heat exchanger, expansion turbine, instrumentation, vacuum vessel etc. At present most of these process plants operate at medium or low pressure due to its inherent advantages. A basic component which is essential for these processes is the turbo expander. The main aim of this project to attain a minimum temperature and pressure and to study the variation of Mach number and entropy. This is done by computational fluid flow analysis of high speed rotating turbine. This involves with the three dimensional analysis of flow through a radial expansion turbine, using nitrogen as flowing fluid. The work is performed on various modules of Ansys that is BladGen, TurboGrid, CFX-Pre, CFX-Post. Bladegen is used to create the model of turbine using available data of hub, shroud and blade profile. Turbogrid is used to mesh the model. CFX-Pre is used to define the physical parameters of the flow through the Turbo expander. CFX-Post is used for examining and analyzing results. Using these results variation of different Proc. Of the Int. Conf: ARIMPIE-2015 thermodynamic properties like Temperature, Pressure, Mach number, entropy etc. inside the turbine can be seen. Several graphs are plotted showing the variation of pressure, temperature, entropy and Mach number along streamline and span wise to analyze the flow through cryogenic turbine. Keywords—Radial Turbogrid, CFX I. turbine, Bladegen, INTRODUCTION Turbo expanders are high speed rotating devices typically used in cryogenic applications including natural gas, petrochemicals and air separation industries. As high pressure gas is expanded across the turbine to produces cryogenic temperature, the majority of the energy potential in the gas is extracted and transferred through the shaft to run the compressor. Though nature has provided an abundant supply of gaseous raw materials in the atmosphere (oxygen, nitrogen) and beneath the earth’s crust (natural gas, helium), we need to harness and store them for meaningful use. For large-scale storage, transportation and for low temperature applications liquefaction of the gases is necessary. For producing atmospheric gases like nitrogen, oxygen and argon in large scale, low temperature distillation provides the most economical route. The low temperature required for liquefaction on of common gases can be obtained by several processes. Compared to the high and medium pressure systems, turbine based plants have the advantage of high thermodynamic efficiency, high reliability and easier integration with other systems. The expansion turbine is the heart of a modern cryogenic refrigeration or separation system. Cryogenic process plants may also use reciprocating expanders in place of turbines. II. OVERVIEW OF CRYOGENIC TURBOEXPANDER The turboexpander essentially consists of a turbine wheel and a brake compressor mounted on a single shaft, supported by the required 122 ELK Asia Pacific Journals – Special Issue number of journal and thrust bearings. These basic components are held in place by an appropriate housing, which also contains the fluid inlet and exit ducts. The basic components are turbine wheel, brake compressor, shaft, nozzle, bearing, diffuser, seals, etc. Proc. Of the Int. Conf: ARIMPIE-2015 passage has a profile of a three dimensional converging duct, changing from purely radial to an axial-tangential direction. Work is extracted as the process gas undergoes expansion with corresponding drop in static temperature. III. OBJECTIVE OF PRESENT INVESTIGATION In the technologically advanced countries many industrial gas manufacturers have switched over from the high-pressure Linde and medium pressure reciprocating engine based Claude systems to the modern expansion turbine based, low pressure cycles. Thus in modern cryogenic plants use turboexpander as one of the most important components. For the development of computational fluid flow analysis of turbo expander system this project thas been initiated. The objectives include: (i) building computational fluid dynamic knowledge base on cryogenic turboexpanders (ii) construction of a computational fluid flow model and study of its performance. IV. LITERATURE REVIEW Most of the rotors for small and medium sized plants are vertically oriented for easy installation and maintenance. It consists of a shaft with the turbine wheel fitted at one end and the brake compressor at the other. The highpressure process gas enters the turbine through piping to the cold end housing and, from there, into the nozzle ring. The fluid accelerates through the converging passages of the nozzles. Pressure energy is transformed into kinetic energy, so that reduction in static temperature takes place. The high velocity gas streams impinge on the rotor blades, imparting force to the rotor and creating torque. The nozzles and the rotor blades are so aligned as to eliminate sudden changes in flow direction and consequent loss of energy. The turbine wheel is of radial or mixed flow geometry, i.e. the flow enters the wheel radially and exits axially. The blade One of the main components of most cryogenic plants is the expansion turbine or the turboexpander. Since the turboexpander plays the role of the main cold generator, its properties- reliability and working efficiency to a great extent, affect the cost effectiveness parameters of the entire cryogenic plant. The concept that an expansion turbine might be used in cycle for the liquefaction of gases was first introduced by Lord Rayleigh in a letter to “Nature” dated June 1898. He discussed the use of a turbine instead of a piston expander for the liquefaction of air. In 1898, a British engineer named Edgar C. Thrupppatenteda liquefying machine using an expansion turbine. A simple method sufficient for the design of a high efficiency expansion turbine is outlined by Kun et. al [1-2]. Agahiet. al. [3-4] have explained the design process of the turboexpander utilizing modern technology, such as CFD software, Computer Numerical Control Technology and Holographic Techniques to further improve anal ready 123 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 impressive turboexpander efficiency performance. Several characteristics values are used for defining significant performance criteria of turbo machines such as turbine velocity ratio, pressure ratio, flow coefficient factor and specific speed [5]. Balje has presented a simplified method for computing the efficiency of radial turbo machines and for calculating their characteristics [6].The concept of specific speed was first introduced for classifying hydraulic machines. Balje [7] introduced this parameter in design of gas turbines and compressors. PhD dissertation of Ghosh [8] explains the detailed summary of technical features and experimental analysis of cryogenic turboexpander. S.K. Ghosh, R.K. Sahoo, S.K. Sarangi in 2005 gave a computational approach to the design of a cryogenic turbine blade profile[9]. considered as the mean surface within a blade. The solid surface are developed using non uniform rational B splines. The suction and pressure surfaces of two adjacent channels are computed by translating the mean surface in the positive and negative theta direction through half the blade thickness. Blade merge topology property is used after making all the surfaces. The blade faces will be merged where they are tangent to one another. Create fluid zone property is selected, to create a stage fluid zone body for the flow passage, and an enclosure feature to subtract the blade body. This resulting enclosure can be used for a CFD analysis of the blade passage. Create all blades this property is used to create All the blades are created using create all blades property by specifying the number of blades in the Bladegen model. Here we are using ten numbers of blades. Different views and curves of radial expansion turbine in bladegen are as following. V. COMPUTATIONAL ANALYSIS FLUID FLOW Mainly three steps are involved in computational fluid flow analysis of turboexpander. Bladegen is used to create the model of turbine using available data of hub, shroud and blade profile. Turbogrid is used to mesh the model. CFX-Pre is used to define and specify the simulation settings and physical parameters required to describe the flow through turboexpander at inlet and outlet. CFX-Post is used for examining and analyzing results. The present design procedure is available in literature [8]. VI. BLADEGEN MODEL DESIGNING OF Fig.1 Meridional blade profile with different spans THE Designing of model is done by Bladegen module available in Ansys by using available hub, shroud and blade profile coordinates. The hub and the tip streamlines are taken from the literature [8, 9]. The hub and tip streamlines are joined with a set of tie lines to create a surface. Blade Editor will loft the blade surfaces in the streamwise direction through curves that run from hub to shroud. The surface so generated is 124 ELK Asia Pacific Journals – Special Issue Fig.2 Variation of beta and theta at different spans Proc. Of the Int. Conf: ARIMPIE-2015 Fig.4 Turbine rotor view after importing from Bladegen Fig.3 Solid Model of turbine generated in Bladegen VII. MESHING OF TURBINE MODEL Turbogrid is used for meshing of model. High quality hexahedral meshes are created that are tuned to the demands of fluid dynamic analysis in turbine rotor. Geometry information regarding turbine rotor is imported from bladegen. Turbogrid uses this bladegen file to set the axis of rotation, the number of blades, and a length unit that characterizes the scale of the machine. After setting topology definition, mesh data setting is used to control the number and distribution of mesh elements. Here the target number of nodes are set upto 250000 to produce a fine mesh. Before generating the 3D mesh, the mesh quality should be checked on the layers, especially the hub and shroud tip layers. After correcting mesh quality on layers, the mesh is generated with 228640 nodes and 206368 elements. Fig.5 Turbine rotor view after setting topology VIII. PHYSICS DEFINITION OF MESHED MODEL IN CFX-PRE CFX-Pre is also known as physics-definition pre-processor for ANSYS CFX. In CFX, physics of meshed turbine rotor is defined using turbo mode. Under basic setting in turbo mode, we set the machine type as radial turbine and rotation axis to z. In component definition we set component type rotating and set rotation value 218780 rev/min. A list of regions that correspond to certain boundary types will automatically be selected by turbo mode. This information should be reviewed in the Region Information section to ensure that all is correct. Boundary conditions and interfaces are set up using this information. Tip clearance at shroud is set up in the wall configuration option. Physics definition tab is used to set fluid type, analysis type, model data, inflow and outflow boundary templates and solver parameters. After setting physics definition CFX-Pre will try to create appropriate interfaces and boundary conditions using the region names presented previously in the region information. 125 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Fig.6 Flow direction at inlet and outlet IX. OBTAINING RESULTS IN CFX CFDPOST Fig.7 Pressure variation along streamwise inlet to outlet CFD-Post is a flexible, state of art postprocessor. It is used to allow easy visualization and quantitative analysis of results of CFD simulations. Speed of post-processing for turbo machinery simulation can be increased using turbo workspace. It includes all the expected plotting objects like, plans, isosurfaces, vectors, streamlines, contours, animations, etc. Precise quantitative analysis such as weighted average, forces, results, compariso11111ns, built in and user defined macros can be easily done. It can create user defined scalar and vector variables. CFD-Post includes automatic reports, charts, and tables. X. RESULTS AND DISCUSSION Fig.8 Pressure variation along span wise Various graphs and contours available from generated results are as following. TEMPERATURE VARIATION STREAMWISE AND SPANWISE PRESSURE VARIATION STREAMWISE AND SPANWISE ALONG Static and total pressure variation can be seen from the graph below. Total pressure varies from 3 bar to 1.6 bar while static pressure varies from 2.4 bar to 1.27 bar along streamline from inlet to outlet of turbine rotor. ALONG Static and total temperature variation can be seen from the graph below. Total temperature varies from 99.6K to 96.7K, while static temperature varies from 88.2K to 90K along streamline from inlet to outlet of turbine rotor. 126 ELK Asia Pacific Journals – Special Issue Fig.9 Temperature variation along streamwise inlet to outlet Proc. Of the Int. Conf: ARIMPIE-2015 Fig.11 Mach Number variation along streamwise inlet to outlet ENTROPY STREAMWISE VARIATION ALONG Fig.10 Temperature variation along spanwise MACH NUMBER STREAMWISE VARIATION ALONG Fig.12 Entropy variation along streamwise inlet to outlet 127 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Advances in Cryogenic Engineering (1996), V41, 941-947 [4] R. R. Aghai, M. C. Lin, B. Ershaghi, Improvements of the efficiency of the turboexpanders in cryogenic applications Advances in Cryogenic Engineering (1996), V41, 933-940 [5] von der Nuell , W. T. Single - stage radial turbine for gaseous substances with high rotative and low specific speed Trans ASME (1952), V74, 499-51 Fig.13 Velocity vectors at 50% span XI. CONCLUSION This work is a modest attempt at flow analyzing inside a cryogenic turboexpander through computational fluid dynamic. A prototype expander has been designed, meshed and simulated using this recipe. The design procedure covers the designing of hub, shroud and blade profile of turboexpander in Bladegen. A CFX model has been developed for flow analysis inside the turbine rotor. The modelling of the various parts of the turbine is done in Bladegen and the computational fluid flow analysis is done using CFX. Various graphs and contours indicating the variations of temperature, pressure, velocity inside the turbine along the streamline are given. [6] O. E. Balje, A contribution to the problem of designing radial turbomachines Trans ASME (1952), V74, 451-472 [7] O. E. Balje, A study on design criteria and matching of turbomachines: Part-A— similarity relations and design criteria of turbines Trans ASME J Eng Power (1972), 83-101 [8] Ghosh, S.k. “Experimental and Computational Studies on Cryogenic Turboexpander” Ph.D dissertation, NIT Rourkela. [9] Ghosh, S.K., Seshaiah, N., Sahoo, R.K., Sarangi, S.K. Design of Turboexpander for Cryogenic applications, Indian Journal of Cryogenics, Special Issue - Vol.2, 75-81 [10]Dimri, H. “Computaional Fluid Flow Analysis of Cryogenic Turboexpander” M.Tech dissertation, NIT- Rourkela. XII. REFERENCES [1] L.C. Kun, T.C. Hanson, High efficiency turboexpander in a N2 liquefier AICHE Spring meeting, Houston, Texas (1985). [2] L. C. Kun, Expansion turbines and refrigeration for gas separation and liquefaction Advances in Cryogenic Engineering (1987), V33, 963-973 [3] R. R. Aghai, M. C. Lin, B. Ershaghi, High Performance cryogenic turboexpanders 128 ELK Asia Pacific Journals – Special Issue 22. THERMAL ANALYSIS OF VARIOUS PERFORATED TREE SHAPED FIN ARRAY USING ANSYS Sachin Kumar Gupta, Rahul Singh, Divyank Dubey, Harishchandra Thakur Gautam Buddha University Greater Noida, India
[email protected] [email protected] Abstract—The effective heat transfer from surfaces using various shapes and sizes extended surface has been a constant research interest. In the field of electronics, augmentation of heat transfer using fins has been a continuous challenge. With the evolution of various structures and materials to manufacture fins has progress more quickly to the research. The present paper discusses the possibility of using different types of perforated and non-perforated tree fin array as a fin for a processor in a computer terminal. The investigation is conducted to compare heat transfer from arrays of Tree fins without and with different perforations. This would be accomplished by 3D modeling and analysis using ANSYS, 14.5. The main goal is to increase the heat transfer rate through the fin surface and saving material cost. Savings in materials and energy provide strong motivation for the development of improved methods of enhancement. The perforations are applied to smooth surfaces to promote flow mixing and initiate turbulence in the flow. Seven fins are designed in this research first fin is plane tree fin, three having 6 perforation and another having 12 perforation of different shapes (circle, square and ellipse). The different shape perforations on the fins have same cross section area. The results show that for same base temperature the greater perforated fins having higher temperature drop then lesser numbered perforated tree fins and plane tree fin. Square perforated tree fin gives best value of temperature drop than the other perforated tree fins and plane tree fin. Keywords—tree shaped fin, , perforated fin, convection, heat transfer, Proc. Of the Int. Conf: ARIMPIE-2015 I. INTRODUCTION In today’s modern age the miniaturization of mother boards and processors and the sudden spurt in their usage has intensified the search for the right kind of heat dissipation mechanisms from electronic chips. The heat transfer can be augmented by the three different techniques such as Passive techniques, Active techniques and Compound techniques. The active heat transfer augmentation techniques have not found commercial interest because of the capital and operating cost of the enhancement devices. The majority of passive techniques employ special surface geometry or fluid additives for augmentation . Passive techniques are the best enhancement techniques. Extended surfaces are widely used passive techniques to augment heat transfer. II. CLASIFICATION OF ENHANCEMENT TECHNIQUES Heat transfer enhancement or augmentation techniques refer to the improvement of thermo hydraulic performance of heat exchangers. Existing enhancement techniques can be broadly classified into three different categories: 1. Passive Techniques 2. Active Techniques 3. Compound Techniques. The effectiveness of any of these methods is strongly dependent on the mode of heat transfer (single- phase free or forced convection, pool boiling, forced convection boiling or condensation, and convective mass transfer), and type and process application of the heat exchanger. a. Passive Techniques These techniques use surface or geometrical modifications to the flow channel by adding inserts or additional devices. They alter the existing flow behaviour (except for extended surfaces) which promote higher heat transfer coefficients also increase pressure drop. Passive techniques do not require any direct input of external power rather use it from the system itself which leads to an increase in fluid pressure drop. Heat transfer augmentation by these techniques can be achieved by using:[3] 129 ELK Asia Pacific Journals – Special Issue (i) Treated Surfaces: Surface having a fine scale alter their finish or coating which may be continuous or discontinuous. They are used for Boiling and condensing duties. (ii) Rough surfaces: The surface modification which promote turbulence in the flow field. (iii) Extended surfaces: It provide effective heat transfer and modified finned surfaces also led to improve the heat transfer coefficients by disturbing the flow field in addition to increasing the surface area. (iv) Displaced enhancement devices: These are the inserts that are used primarily in confined forced convection, and they improve energy transport indirectly at the heat exchange surface by displacing the fluid from the heated or cooled surface of the duct with bulk fluid from the core flow. (v) Swirl flow devices: They produce and superimpose swirl flow or secondary recirculation on the axial flow in a channel. These include helical strip or cored screw type tube inserts, twisted tapes. They can be used for single phase and two-phase flows. (vi) Coiled tubes: These lead to relatively more compact heat exchangers. It produces secondary flows and vortices which promote higher heat transfer coefficients in single phase flows as well as in most regions of boiling. (vii) Surface tension devices: These consist of wicking or grooved surfaces, which direct and improve the flow of liquid to boiling surfaces and from condensing surfaces. (viii) Additives for liquids: These include the addition of solid particles, soluble trace additives and gas bubbles in single phase flows and trace additives which usually depress the surface tension of the liquid for boiling systems. (ix) Additives for gases: It include liquid droplets or solid particles which are introduced in single- phase gas flows either as dilute phase (gas-solid suspensions) or as dense phase (fluidized beds). b. Active Techniques These techniques are more complex from the application and design point of view as the Proc. Of the Int. Conf: ARIMPIE-2015 method requires some external power input to cause the desired flow modification and to improve heat transfer rate. It have limited application as it require external power as it is difficult to provide external power input in many cases. Augmentation of heat transfer by this method can be achieved: (i) Mechanical Aids: Instrument stir the fluid by mechanical means or by rotating the surface which includes rotating tube heat exchangers and scrapped surface heat exchangers. (ii) Surface vibration: Applied in single phase flows to obtain higher heat transfer coefficients. (iii) Fluid vibration: Used in single phase flows and considered to be the most practical type of vibration enhancement technique. (iv) Electrostatic fields: The form of electric or magnetic fields or a combination of the two from dc or ac sources, which can be applied in heat exchange systems involving dielectric fluids. Depending on the application, it can also produce greater bulk mixing and induce forced convection or electromagnetic pumping to augment heat transfer (v) Injection: Technique is used in single phase flow and pertains to the method of injecting the same or a different fluid into the main bulk fluid either through a porous heat transfer interface or upstream of the heat transfer section. (vi) Suction: removal through nucleate or film through a porous flow. It involves either vapour a porous heated surface in boiling, or fluid withdrawal heated surface in single-phase (vii) Jet impingement: It involves the direction of heating or cooling fluid perpendicularly or obliquely to the heat transfer c. Compound Techniques A compound augmentation technique is the one in which more than one of theabove mentioned techniques is used in combination for improving the thermo-hydraulicperformance of a heat exchanger. 130 ELK Asia Pacific Journals – Special Issue III. LITERATURE REVIEW A variety of experimental, analytical and Numerical research work has been carried out on enhancing of heat transfer. The tree shaped flow paths are the most common and visible way of distribution in the engineering as well as the actual world entity propagation. The tree shaped flow paths have been put in place on the principle of global optimization of system performance subject to global constraints [1]. The intension of optimization is the minimization of overall resistance offered by the volume-point flow. Thermal performance and mass minimization of extended surfaces was studied for rectangular, pin and triangular shaped arrays for effective heat dissipation from various surfaces by different convection models natural and forced[2,3,4,5,]. With the various availability of latest materials and methodologies of transport and thermal media deposition, the landscape of heat dissipation has changed. A systematic theoretical investigation of the effects of fin spacing, fin height, fin length and temperature difference between fin and surroundings on the free convection heat transfer from horizontal fin arrays was carried out with a parametric study to ascertain optimum performance, this performance was analyzed and shown that it cannot be obtained from one or two parameters[6]. Experimental investigations on pin-fin arrays subjected to forced convection environments to find the dependencies of nusselt number on Reynolds number yielded good results [7]. The effect of free convective heat transfer from fins and fin arrays attached to a heated horizontal base was experimentally studied [8]. The technique of variable interferometry has been exploiting and experiments have been carried out under steady state conditions. The utilization of tree shaped fins for effective heat dissipation in space environment was studied [9]. This paper discusses about different tree fin shaped for Aluminium materials keeping volume constant. The usages of square fins in the heat sink used for the processor were result to be lower heat conducting capability than other tree fins. Proc. Of the Int. Conf: ARIMPIE-2015 IV. ANALYTICAL ANALYSIS Numerical studies were conducted to determine the heat transfer on the different aluminium fins for natural convection.Analytical study has been calculated on following assumptions: 1. The fin material is homogeneous and isotropic. 2. The heat transfer coefficient is uniform over the fin surface. 3. There are no heat sources within the fin itself. 4. There is no free convection or radiation heat transfer. V. CFD MODELING AND SIMULATION The model is designed in Solidworks and simulation performed in ANSYS 14.5. Workbench environment with ANSYS system of steady state thermal has the capability of solving the convective transport of energy and the thermal conduction in solids. In the any CFD simulation, the steps in performing fluid analysis are: 7) Modeling in Solidworks 8) Import the geometry in ANSYS steady state thermal 9) Generating mesh 10) Set up the analysis by providing boundary conditions 11) Control and monitor the solver to achieve a solution 12) Visualize the results and create a report. a. Create Geometry Different fin geometries were designed using Solidworks software which is specifically designed and preparation of geometry for simulation. The selection of tree fins with three stems is selected with the angle between the stems taken as 90oas has been reported to be the best when considering other angles of 30o and 60o[9]. 131 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Figure 12: (a) Tree fin with 6 perforation (b)Tree fin with 12 perforation B.Create Mesh for the Geometry Figure 11: Sketch of the proposed plane tree fin In this research we made tree fins having base sheet length of 100×100×10mm, height of the fin 55 mm and its thickness is 5 mm as shown in fig 2. TABLE I. TABLE 1: DIMENSIONS OF GIVEN TO THE TREE FIN Steam Number( S) Lengt h (mm) Slot Dimensio n (mm×m m) 1 25.0 10 5 None 2 17.7 7.1 5 5×5 3 12.5 5 5 3.55×3.5 5 4 12.5 5 5 2.5×2.5 There are 6 newly designed fins in which 3 fins having 6 perforation and another 3 fins having 12 perforation of square, circular, and elliptical shape shown in fig1. The base areas of various perforated shapes are kept same to know the effect of shape on heat transfer through perforated fin. a) Widt h (mm) Dept h (mm ) The standard Mesher in a Steady State Thermal which enables an automatic mesh generation using efficient mesh generation techniques, meshes were created with high contact sizing relevance (dense meshing near the dimple surface). The total number of elements and nodes are 6564 and 13678 respectively. C.Analysis Setup Under Steady State Thermal of the ANSYS Workbench, appropriate materials Aluminum assigned to the created fin. Then we move to setup for applying boundary conditions to the fin. The temperature of base of fin is fixed at 95oC and natural convective heat transfer from other face of the fins. D. Visualizing the Results When the solver was terminated, the results were examined which is the post processing step. Temperature distributionand heat flux along the fin surface as well as parameters and changes in other parameters can also be predicted by computational analysis. Fig.3 shows the temperatureover the convective surface area of the plane, 6 perforated and 12 perforated fins respectively. It can be seen that the larger perforated fin are pumping out the more heat from the base. The top ends of the fins are cooled faster. b) a) 132 ELK Asia Pacific Journals – Special Issue b) c) d) Proc. Of the Int. Conf: ARIMPIE-2015 e) f) g) Figure 13: Temperature contours a) plane b) 6 circular perforation c) 12 circular perforation d) 6 elliptical perforation e) 12 elliptical perforationf) 6 square perforation g) 12 square perforation 133 ELK Asia Pacific Journals – Special Issue a) b) c) Proc. Of the Int. Conf: ARIMPIE-2015 e) f) g) Figure 14: Heat Flux contoursa) plane b) 6 circular perforation c) 12 circular perforation d) 6 elliptical perforation e) 12 elliptical perforationf) 6 square perforation g) 12 square perforation d) 134 ELK Asia Pacific Journals – Special Issue VI. RESULTS AND DISCUSSION The simulation investigates the perforationshape geometry effect on the convective heat transfer from the tree fins by Natural Convection. In this study a comparison is made between different shapes of perforation in as shown in fig 4.The comparison of different tree fin by using temperature distribution along the fin. The results show that, thehighest temperatures were along the non-perforated tree fin, and lower temperatures distributionalong the perforation fins with square shaped.Also, the difference between temperature in the base of fin and its tipregarded from the important factors in the perception of the work of the fin, which it can beused to compare this factor with other fins. and through the same graphics canbe say that, the highest drop of temperature between the tree fin's base and it is tip occur in the square perforated tree fin. This happen because the square area destroyed the area of thermalboundary layer larger than the rest shapes. It also shows that greater the number of perforation larger will be the temperature drop along the tree fin and larger will be heat dissipation. Proc. Of the Int. Conf: ARIMPIE-2015 95 85 75 65 55 45 35 0 10 20 30 40 50 55 Tree Plane Fin 6 Circular Perforation 6 Square Perforation 6 Ellipse Perforation 12 Circular Perforation 12 Square Perforation 12 Ellipse Perforation Figure 15: Temperatures attained by the various tree fin along the length from base 50 45 40 35 30 25 20 15 10 5 0 Figure 16: Graph showing the minimum temperatures attained by various tree fins for Aluminium alloy 135 ELK Asia Pacific Journals – Special Issue From figure 5, shows the minimum temperature attains by the various tree fins. It is found from the graphs that fins with greater number of slots having minimum temperatures compared to fins without slots and fins with lesser number of slots due to increase in effective heat transfer surface area (45.617oC without slots and 37.307oC with 12 number of square perforation are present on the stems of the tree fin made of Aluminium alloy at a chip temperature of 95oC). VII. o o o o o Proc. Of the Int. Conf: ARIMPIE-2015 [5] [6] CONCLUSION The array of tree fins with 12 number of perforation having a better heat transfer capability when compared to a tree fin without perforation and with 6 number of perforation. Aluminium alloy can be used in the shape of tree fins with greater number of perforation as a heat sink for an effective transfer of heat being generated. It is concluded that the maximum heat transfer ratewill takes place in12 square perforationtree fin . The heat transfer coefficient is maximum for bothaluminium in square perforated surface tree fin. Perforated fin leads to decrease the expenditure of the material [7] [8] [9] Dissipating Heat by Natural Convection, International Journal of Engineering and Innovative Technology (IJEIT),2(11), 2013, 245-249. YogeshJaluria, Jing Yang,A Review of Microscale Transport in the Thermal Processing of New and Emerging Advanced Materials, Journal of Heat Transfer, 133, JUNE 2011, Senol Baskaya, Mecit Sivrioglu, Murat Ozek, Parametric study of natural convection heat transfer from horizontal rectangular fin arrays, International Journal of Thermal Sciences, 39(8), pp. 797–805, 2000. M Tahat, Z.H Kodah, B.A Jarrah, S.D Probert, Heat transfers from pin-fin arrays experiencing forced convection, Applied Energy, 67(4), pp.419–442, 2000. C. B. Sobhan, S. P. Venkateshan, K. N. Seetharamu, Experimental studies on steady free convection heat transfer from fins and fin arrays, Wärme - und Stoffübertragung, 25(6), pp 345-352, 1990. David Calamas, John Baker. Behavior of Thermally Radiating Tree-like Fins, Journal of Heat Transfer, 135, AUGUST 2013. 23. References [1] [2] [3] [4] A Bejan, Shape and Structure, Engineering to nature, (Cambridge University Press, Cambridge, UK, 2000). N MacDonald, Trees and Networks in Biological Models (Wiley, Chichester, UK, 1983). R. Sam Sukumar, G.Sriharsha, S.BalaArun, P.Dilipkumar, Ch.Sanyasi Naidu, Modelling And Analysis Of Heat Sink With Rectangular Fins Having Through Holes, International Journal of Engineering Research and Applications(IJERA), 3(2), 2013, 1557-1561. S M.Wange, R.M.Metkar, Computational Analysis of Inverted Notched Fin Arrays 136 ELK Asia Pacific Journals – Special Issue 23. A REVIEW ON THE ANALYTICAL ANALYSIS AND MODELING OF EARTH AIR TUNNEL HEAT EXCHANGER Jagjit Kaur#1 Department of Mechanical Engineering, Guru Nanak Dev Engineering College, Ludhiana, Punjab, INDIA. Email:
[email protected] Harminder Kaur#2 Department of Electronics and Communication Engineering, Guru Nanak Dev Engineering College, Ludhiana, Punjab, INDIA. Email:
[email protected] Abstract: Today we primarily use fossil fuels to heat and power our homes. It’s convenient to use coal, oil, and natural gas for meeting our energy needs, but we have a limited supply of these fuels on the Earth. We’re using them much more rapidly than they are being created. Eventually, they will run out. And because of safety concerns and waste disposal problems it gives globalization problems. Research is carried out in order to increase a share of renewable energy source in the overall task of energy generation. Various research efforts have been rationalized to prove the benefits these could be derived from the utilization of renewable energy for electricity. These sources are currently offered worldwide as an environment friendly which is the major focal advantage. In a developing country like India, there is a huge gap in demand and supply of electricity and rising electricity prices have forced us to look for cheaper and cleaner alternative. Earth air tunnel heat exchangers are simple systems to save energy in buildings. The EATHEs are considered as one of the most passive system due to its ability to provide both the effects; heating in cold months and cooling during warm months. They use the earth’s near constant subterranean temperature to warm or cool air for residential, agricultural or industrial used. This paper reviews on the experimental and analytical studies of EATHE systems around the world. Proc. Of the Int. Conf: ARIMPIE-2015 Abbreviations: EATHE earth air tunnel heat exchanger Keyword: Fossil fuels Earth air tunnel heat exchanger; renewable energy; passive system I. INTRODUCTION Energy security and stability are currently the main issues throughout the world. Looking to the energy crisis world over the importance of energy for the existence of our society, it is imperative and urgent to find alternative source to replace conventional fuel or at least mitigate its widespread consumption and consequent impact on the environment. Passive heating or cooling systems are known for their advantage of consuming no or very less energy as compared to the active heating and cooling system. EATHE is one of the most passive system due to its ability to provide both the effects; heating in cold months and cooling during warm months. The thermal capacity of earth is such that the diurnal variations of the surface temperature do not penetrate much deeper than 0.5 m and seasonal variations up to a depth of about 3m. Beyond this depth the earth’s temperature remains constant. The value of this temperature is usually seen to be equivalent to the all year mean of the soil air temperature of its surface. Therefore at sufficient depth, the ground temperature always higher than that of the outside air in winter and is lower in summer. The earth’s thermal potential energy may be exploited using EATHE system. II. TYPES OF EARTH There are mainly two types of heat exchangers. One is open systems and second is closed systems. In open systems, ambient air passes through tubes buried in the ground for preheating or pre-cooling and then the air is heated or cooled by a conventional air conditioning unit before entering the building. A. Open system: In open systems, ambient air passes through tubes buried in the ground for 137 ELK Asia Pacific Journals – Special Issue preheating or pre-cooling and then the air is heated or cooled by a conventional air conditioning unit before entering the building. It has some advantages over others which are; Simple design; lower drilling requirements than closed-loop designs; subject to better thermodynamic performance, typically lowest cost. Proc. Of the Int. Conf: ARIMPIE-2015 augmented for further moisture reduction, active or passive systems may treat the air stream. Formal research indicates that EATHE reduce building ventilation air pollution. Whenever using earth tubes with or without antimicrobial material, it is extremely important that the underground cooling tubes have an excellent condensation drain and be installed at a 2-3 degree grade to ensure he constant removal of condensed water from the tubes. IV. Fig. 1 Open Type Earth Air Tunnel Heat Exchanger [5] B. Closed system: In closed systems the heat exchangers are located underground, either in horizontal, vertical or oblique position, and a heat carrier medium is circulated within the heat exchanger, transferring the heat from the ground to a heat pump or vice versa. Fig. 2 Closed type Earth Air Tunnel Heat Exchanger [5] III. SAFETY If humidity and associated mold colonization is not addressed in system design, occupants may face heath risk. At some sites, the humidity in the earth tubes maybe controlled simply by passive drainage if water table is sufficiently deep and the soil has relatively high permeability. In situations where passive drainage is not feasible or needs to be EFFECTIVENESS Implementation of EATHE for either partial or full cooling and/ or heating of facility air have had mixed success. EATHE can be very cost effective in both up front or capital costs well as long term operation and maintenance costs. However this varies widely depending on location’s latitude, altitude, ambient earth temperature, climatic temperature, relative humidity extremes, solar radiation, water table, soil type, soil moisture content and the efficiency of the building’s exterior envelope design. Generally dry and low density soil with little or no ground shade will yield the least benefit, while dense damp soil with considerable shade should perform well. A slow drip watering system may improve thermal performance. Damp soil in contact with the cooling tube conducts heat more efficiently than dry soil. Earth cooling tubes are much less effective in hot humid climates where ambient temperature of solar thermal buffer zone the earth approaches human comfort temperature. The higher the ambient temperature of earth, the less effective they are for cooling and dehumidification. However, they can be used to partially cool and dehumidify the replacement fresh air intake for passive solar thermal buffer zone areas. Not all regions and sites are suitable for EATHE. Conditions which may hinder or preclude proper implementation include shallow bedrock, high water tables, and insufficient space, among others. In some areas only cooling or heating may be afforded by EATHE. In these areas, provision for thermal recharge of the ground must especially be considered. 138 ELK Asia Pacific Journals – Special Issue V. DESCRIPTION OF EATHE It is underground heat exchangers that can capture heat from or dissipate heat to the ground. They use the earths near constant subterranean temperature to warm or cool air or other fluids for residential, agricultural or industrial uses. Temperature difference between air and soil can be utilized to pre cool and pre heat ventilated air supply using EATHE in summer and winter respectively. An earth air heat exchanger consist of one or more tubes lied under the ground in order to cool in summer or pre-heat in winter, the air to be supplied in a building. The physical phenomenon of earth air heat exchanger is simple: the ground temperature commonly higher than the outdoor air temperature in winter and lower in summer, so it makes the use of the earth convenient as warm or cold sink respectively. Both of the above uses of earth air heat exchanger can contribute to reduction in energy consumption. Several researchers have described the earth-to-air heat exchangers (EATHE) coupled with buildings as an effective passive energy source for building space conditioning. An earth-to-air heat exchanger system suitably meets heating and cooling energy loads of a building. Its performance is based upon the seasonally varying inlet temperature, and the tunnel-wall temperature which further depends on the ground temperature. The performance of an EATHE system depends upon the temperature and moisture distribution in the ground, as well as on the surface conditions. The principle of using ground inertia for heating and cooling is not a new concept, but rather a modified concept that goes back to the Ancients. This technology has been used throughout history from the ancient Greeks and Persians in the pre- Christian era until recent history (Santamouris and Asimakopoulos, 1996). For instance the Italians in the middle Ages used caves, called colvoli, to pre-cool/pre-heat the air before it entered the building. The system which is used nowadays consists of a matrix of buried pipes through which air is transported by a fan. In the summer the supply air to the building is cooled due to the fact that the ground Proc. Of the Int. Conf: ARIMPIE-2015 temperature around the heat exchanger is lower than the ambient temperature. During the winter, when the ambient temperature is lower than the ground temperature the process is reversed and the air gets pre-heated. VI. EXPERIMENTAL AND ANALYTICAL ANYLASIS An EATHE is an underground heat exchanger that can capture heat from and/ or dissipate heat to the ground. It is used geothermal energy for many applications like agricultural or industrial uses, heat recovery ventilation, and alternate to conventional central heating or air conditioning. In this chapter research papers are considered for understanding the effect of different parameters under different conditions. Jacovides et al. (1995) described a TRNSYS model for the simulation of earth tube systems (TRNSYS is a computer modeling tool). They did not discuss the general potential of earth tubes for cooling or heating. The model includes latent heat transfer phenomena between the air and the pipe, and models the moisture content of the air circulating in the pipe and moisture migration through the soil with a temperature and moisture gradient. In the case studied (which is mostly applicable to greenhouses), the earthto-air heat exchanger is buried under the foundation of the building. Ground temperature is therefore a superposition of the soil temperature field due to surface ground temperature and the temperature field due to the pipes themselves. Limited validation of the model was provided, as the time period was short (two summer months) and relative humidity was not measured. Mihalakakouet et al. (1996) provided simulation data for an earth tube system in Dublin, Ireland, and study the influence of pipe length, pipe radius, air flow velocity, and soil depth. The data shown indicated that with a system featuring a 30 m long, 125 mm diameter tube buried 1.2 m underground, with air velocities of 8 m/s, one can expect a maximum rise of air temperature between 2.1 and 7.9°C, depending upon the time 139 ELK Asia Pacific Journals – Special Issue of year. These values increase roughly by 1°C for each additional meter in depth, and by 0.5 to 0.9°C for each additional 20 m in length. Lower velocities increase the temperature rise, and so do smaller diameters. However there was no discussion about the global energy performance of the system, which should include the energy used to power the fans. Also, it doesn’t either provide a summary of energy gains on a monthly basis. Gauthier et al. (1997) presented a fully transient three-dimensional heat transfer model of heat pipes. The model can handle multiple pipes, non-homogeneous soil properties, transient boundary conditions, and evaporation and condensation in the pipes. The model was validated against data from an earth tube system installed in a commercial greenhouse in Canada (unfortunately, only 3 days of data is used, probably because the model is very computationally expensive). They concluded with a parametric study to quantify the effect of various system variables. Deglin et al. (1999) conducted a theoretical model, with a particular application to livestock buildings; validation using an experimental setup is detailed. Corrugated, non-perforated plastic pipes were used. Validation was done with one year of data for a system including 18 m long, corrugated PVC pipes with 3 different diameters (250, 315 and 400 mm), buried at three different depths (1.50, 2.25 and 3.00 m). The authors concluded that (1) soils saturated in water are better from a thermal point of view, (2) greater depths are preferable since they provide higher temperatures in winter and lower temperatures in summer, (3) smaller pipes are more thermally efficient, i.e. they result in a higher heat exchange per unit volume of air; however they cause greater pressure losses and require larger installations (4) lower fan speeds lead to higher efficiencies, and (5) 70% of the heat transfer occurs within the first 10 m of the pipe. Sawhney et al. (1999) described a recirculation underground system made with concrete pipes. The system is used to air-condition a building in a tropical climate. The pipes form a closed circuit. Metal wire mesh is used to prevent insects and foreign matter from entering. The system is designed to work both for cooling and heating. Only one month of monitoring (May) was done. Air from the house is cooled by Proc. Of the Int. Conf: ARIMPIE-2015 around 1.5°C as it passes through the system. Temperature of air delivered by the system is fairly stable (around 27°C, - 13 - which is the ground temperature for the location). Relative humidity is somewhat higher (5%) than that of a non-conditioned room; that is, moisture is added as it is circulated through the tubes. Given that a 3 HP blower is used to circulate the air, the COP was found to be only 3.35. Staahl (2002) focused on the quality of the air coming out of earth tubes, particularly related to the moisture content. The author noted that the material of the earth-tube wall is of great importance since it determines the moisture transfer: for example concrete will let the moisture through, plastic will not. For that reason the relative humidity predicted by the author for a concrete tube is 100% year round. For a plastic tube it reaches 100% only in summer in a Nordic climate. Over half the year the relative humidity is above 80%, which is conducive to mold growth. He also mentioned mold growth in two of three Swedish schools equipped with earth tubes. On the energy side, the author predicted(through simulations) that an earth tube will typically deliver 1,200 kWh/yr to a house in the Swedish climate, or about 10% of the heating needs. Bansal et al. (2009) developed a mathematical modeling to investigate the potential of storage capacity of the ground for cooling with the help of an EATHE system integrated with evaporative cooler. From mathematical model they concluded that for a given diameter of pipe, volumetric flow rate set of inlet &outlet temperature owing to coupling the evaporative cooler with EATHE, there is a decrease in the length of the buried pipe. This decrease is found to be in the range of 0.9-93.5% of length. They also concluded the decrease in length also depends upon the bypass factor that decreases by 93.5-22.9% when factor decreases from 0.2-0.5. Bansal et al. (2011) presented enhancement in the performance of simple EATHE by integrating an evaporative cooler at outlet. After experimentation the result showed that while ambient air itself is comfortable for 25.65 of the hours, use of integrated EATHE- evaporative cooling system provides comfortable air for 34.16% hours in one year; whereas simple 140 ELK Asia Pacific Journals – Special Issue EATHE is able to provide comfortable air only for 23.33%additional hours. They found that on annual basis the integrated EATHE-evaporative cooling system delivers 4856 MJ of cooling effect, 4500MJ is achievable with simple EATHE system and remaining 3190MJ is achieved due to integration of EATHE with evaporative cooling at its outlet. Bansal et al. (2012) made an attempt to enhance the performance of active cooling system by coupling it with EATHE in four different hybrid modes. In mode I air conditioner alone supplied the conditioned air to the room and EATHE is not functional. In mode II air conditioner supplies conditioned air to the room and 100% conditioned air from EATHE is also delivered directly to the room. Air conditioner supplies the conditioned air to room and 100% conditioned air from EATHE is used for cooling the condenser tubes of air conditioner during mode III. In mode IV air conditioner supplies the conditioned air to room and 50% conditioned air from the EATHE is fed to the room directly and remaining 50% air is used for condenser cooling of air conditioner. After experimentation they have investigated the thermal performance of the developed 1.5 TR window type air conditioner and found the power consumption to be reduced by 18.1% when cold air from EATHE is completely used for condenser cooling of the air conditioner. VII. CONCLUSION The ground or earth acts as a very large store of heat energy. It can be used as a heat source in winter or a heat sink in summer. The ground can be used to moderate the temperature in buildings standing on it. A ground heat exchanger can be used to extract heat energy from the ground in winter season to transfer the heat into houses at the same time, it can be used to provide a very efficient mechanism for heat rejection from buildings, free of all carbon emissions on site. It can make use of solar energy stored in the ground to provide one of the most energyefficient ways of heating or cooling houses. Most systems usually constructed from 4–24inch Proc. Of the Int. Conf: ARIMPIE-2015 diameter, smooth walled, rigid or semi rigid plastic, plastic coated metal pipes or plastic pipes, buried 1.5 to 3m underground where the ambient earth temperature is typically 10 to 23⁰C. Ground temperature becomes more stable with depth. Smaller diameter tubes require more energy to move the air and have less contact surface area. Larger tubes permit a slower air flow, which yields more efficient energy transfer and permits much higher volumes to be transferred, permitting more air exchanges in a short every time period. Sharp 90⁰ angles should be avoided in the construction of the tube. Two 45⁰ bends produce less turbulent, more efficient air flow. REFERENCE [1] Bansal V., Misra R., Agrawal G.D., Mathur J., (2009) “a mathematical modeling to investigate the potential of storage capacity of the ground for cooling with the help of an EATHE system integrated with evaporative cooler”. Energy builds. Vol.42, pp. 645-8. [2] Bansal V., Misra R., Agrawal G.D., Mathur J., (2011) “enhancement in the performance of simple EATHE by integrating an evaporative cooler at outlet”. Energy builds. Vol.52, pp. 745-8. [3] Bansal V., Misra R., Agrawal G.D., Mathur J., (2012) “enhance the performance of active cooling system by coupling it with EATHE in four different hybrid modes”. Energy builds. Vol.42, pp. 645-9. [4] Breesch H., Bossaer B., Janssens A.,(2005),“Passive cooling in a low energy office building”, Energy Build, Vol. (45),pp. 215-222. [5] Dubey Manojkumar,, Bhagoria J.L., Atullanjewar ,(2013), “Earth Air Heat Exchanger in Parallel Connection”, International Journal of Engineering Trends and Technology (IJETT), Vol.4, pp.2463-246 141 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 [6] Gauthier C., LacroixM.,Bernier H., (1997),“Numerical simulation of soil heat exchanger-storage systems for greenhouses”,Renewable Energy, Vol. (36), pp. 125-129. [7] Ghosal G., Argiriou A., Lykoudis S., Balaras C., Asimakopoulos D.,(2004), “ Experimental study of a earth to air heat exchanger coupled with a photovoltaic system”, Journal of solar energy engineering, pp. 189195. [8] Jacovides C .P., Mihalakakou G., (1995), “ An underground pipe system as an energy source for cooling/heating purposes”,Energy conversion management ,Vol. (3), pp. 1463-83 [9] Mihalakakou G., Lewis J. O.,Santamouris M., (1996) , “On the heating potential of buried pipes techniques – application in Ireland”,Energy Buildings,pp. 103-117. [10] Staahl F., (2002), “ Preheating of Supply Air through an Earth Tube System – Energy Demand and Moisture Consequences”, energy build, pp. 315-318. [11] Santamouris, G., Mihalakakou G., Balarar C.A.,(1995), “Use of buried pipes for energy conversation in cooling of agricultural greenhouses,” Solar Energy, Vol. 55,pp. 111124. [12] Shukla Ashish,Tiwari G.N., Sodha M.S.,(2006), “Thermal modeling for greenhouse heating by using thermal curtain and an earth–air heat exchanger,” Building and Environment ,Vol. 41,pp.843–50. [13 ] Sawhney R.L., Buddhi D.,Thanu N.M., (1999), “ An experimental study of summer performance of a recirculation type underground air pipe air conditioning system”, Renewable energy, pp. 26-48. 142 ELK Asia Pacific Journals – Special Issue 24. ECOFLUSH WASTEWATER RECYCLING AND RAINWATER HARVESTING TOILET FLUSH SYSTEM Mukesh Kumar Roy MAE, ASET Amity University Uttar Pradesh Noida, U.P., India
[email protected] Ayush Goyal ECE, ASET Amity University Uttar Pradesh Noida, U.P., India
[email protected] Vivek Kumar MAE, ASET Amity University Uttar Pradesh Noida, U.P., India
[email protected] Abstract—This research work proposes a household wastewater recycling and rainwater harvesting toilet flush system. This approach is economical and prevents the wastage of water at household or domestic level. By recycling wastewater this system avoids the waste of potable water and conserves energy used for pumping groundwater with boring submersibles and purification and filtration of water by municipal corporations or governmental agencies. Furthermore, the collection of rainwater provides an additional source of water for the flush. The recycled wastewater and harvested rainwater will be stored in a tank, which will be regularly treated with chlorine so as to ensure no bacterial growth. The tank storing the recycled wastewater will be connected to the toilet’s flush. This Ecoflush toilet system will save approximately 73000 litres of fresh potable government supply water or groundwater per annum and approximately 200 units of electricity per annum for an average household of 4-5 members. Proc. Of the Int. Conf: ARIMPIE-2015 Keywords—wastewater recycling; rainwater harvesting; energy conservation; toilet flush system; ecoflush I. INTRODUCTION Water is one of the most basic essential needs in our daily life routine. Its scarcity in our life is the biggest fear and thus various methods and systems are developed for its storage and conservation. Reusing rain water and water wasted in domestic purposes is one of the biggest challenges. It is one of the utmost requirements to save this water and recycle it so that it can be used again for different purposes. Previous research on recycling of water for toilet flushing has been published on a method for processing and re-using of gray water for the flushing of toilets, particularly in vacuum toilet systems used in aircraft to optimize the use of available water. A method for processing and reusing gray water for flushing a toilet, comprising the following steps: a) filtering said gray water to provide filtered water, b) collecting said filtered water in a processing tank, c) anodically oxidizing said filtered water in said processing tank to provide processed water, and d) using said processed water for flushing a toilet bowl in a lavatory or toilet [1]. Other previous work relates to a system for the treatment of aircraft toilet waste water to permit discharge of the treated water to the atmosphere during flight, utilizing the pressure differential that is created between the aircraft's cabin pressure and the external atmosphere. The system includes a filter to remove suspended solids and other contaminants from the waste water, and may also include means to purify the water to potable water standards and means to recirculate the treated water for reuse on the aircraft [2]. A third publication in this area describes a water saving device of a flush valve type toilet bowl to economize on water by controlling the quantity of washing water according to urine or feces. The water saving device of a flush valve type toilet bowl comprises: a housing having a space inward; a sensor-cum-controller attached to a space of an upper cap of the housing to sense a user, to distinguish urine or feces 143 ELK Asia Pacific Journals – Special Issue automatically after stool and to drain the corresponding washing water [3]. A fourth area of research in this field relates to infrared-based monitoring signals providing a free water-saving toilet tank control device. The device includes an infrared sensing device with valve control structure; input of the microcontroller I / O with the infrared transmitter and receiver connected to the output, the output of the microcontroller I / O and control motor in series is connected to the water pipe of the pulse switch to perform the opening and closing structure; the switch actuator comprises two sets of switches which are respectively connected to output ends of the coil of the pulse motor [4]. A fifth paper on economical toilet flushing delineates a toilet stool flushing apparatus having two flush water channels, for carrying out pattern-dependent flushing and flushing a toilet stool such that the quantity of flush water is switched between stool flushing and urine flushing, wherein the toilet stool flushing apparatus is comprised of a human body detecting means which is set such that the length of a human body detecting duration correlates with the quantity of flush water, to thereby simplify the equipment and improve the operational ease thereof [5]. A sixth published work in the area of economical flushing relates to a control device of a pressure sensor of a seat toilet, which can be used for automatically distinguishing urine and stool so as to flush. The control device comprises a pressure sensor. The input end of a single-chip is connected with a flag bit of the pressure sensor. According to the time length of human pressure, the control device can automatically distinguish the urine and stool [6]. Various systems are developed that recycle waste water from household and then use it in flush systems of toilets. These systems comprise two flush levels i.e. one for urine and one for stool. Flush water released is dependent on the duration of the user’s stay time but a longer stay time does not always correspond to more stool or urine and thus it results in fresh potable water wastage. Proc. Of the Int. Conf: ARIMPIE-2015 Therefore, in view of the cited prior arts, there is a need to improve the flush system to save potable groundwater and government main supply plant-treated water from being wasted in toilet flushing. Hence, the present work proposes a waterrecycling, energy-conserving toilet flush system which collects water from rain harvesting and recycled shower, sink, kitchen, and laundry wastewater from the household’s sewage drain pipe into a tank for flushing the toilet. II. METHODOLOGY a. Wastewater Recycling and Rain Harvesting System The principal object of the proposed system is to provide an eco-friendly flush system that filters and collects recycled water from a household sewage drain pipe as well as rain harvesting system and uses it in toilet waste flushing to save potable groundwater and government main supply plant-treated water from being wasted in toilet flushing. Still another object of the proposed system is to provide an energy-saving environmentfriendly flush system that reuses water from the kitchen, sink, shower, and washing machine. Another object of the proposed system is to provide a flush system that uses rainwater harvesting as an additional source of water supply and thus reduces the demand of groundwater. Yet another object of the proposed system is to provide a low installation and low running cost water-recycling toilet flush system that avoids expensive water purification as only simple membrane filtration is used for filtering the wastewater stored for toilet flushing. Still another object of the proposed system is to provide a medicated storage of recycled water that automatically releases chlorine into the tank to prevent microbial growth. b. Proposed System Design The proposed system provides an ecofriendly toilet flush system that filters and stores recycled water from household use in a tank for toilet waste flushing to save potable groundwater 144 ELK Asia Pacific Journals – Special Issue and government main supply plant-treated water from being wasted in toilet flushing. The flush system collects water from rain harvesting and recycled shower, kitchen, and laundry wastewater sourced from the household’s sewage drain pipe. The collected water is membrane-filtered and stored in a tank of approximately 200-litre or above capacity. The tank has a drainage pipe in case water exceeds the storage level of the tank. Chlorine is released into the tank on a daily basis to prevent bacterial growth in the recycled water in the tank. The approach is environment friendly and provides an efficient way to reuse the wastewater at house hold level and saves energy required for pumping groundwater with a boring submersible and purification and filtration of main supply water by municipal corporations and government agencies. c. Proposed System Components In a preferred embodiment of the proposed system, the water-recycling, energy-conserving toilet flush system comprises a household waste water collection system from the household’s sewage drain pipe; a rain water harvesting system; water recycling unit; and a storage tank. d. Proposed System Flowchart Figure 1 illustrates the design of our proposed wastewater recycling and rainwater harvesting toilet flush system. Proc. Of the Int. Conf: ARIMPIE-2015 FIGURE 1: FLOWCHART OF THE WASTEWATER RECYCLING AND RAINWATER HARVESTING TOILET FLUSH SYSTEM III. RESULTS On average an Indian household of 4-5 members will require 20 flushes (given that each member requires approximately 4 flushes per day). Each flush is of approximately 10 litres of water, i.e., one household requires 200 litres of flush water per day. Table 1 presents the results of water and energy consumption for an average Indian household using the normal toilet flush and the eco-smart flush system proposed in this paper. TABLE 1: NORMAL VERSUS ECOFLUSH WATER AND ENERGY CONSUMPTION FOR AN AVERAGE HOUSEHOLD Household Potable Consumption water Consumed Electric energy Consumed Normal Toilet ~200 litres / ~22 units / day month (for daily usage of 740 watt pump motor)* Ecoflush Toilet 0 litres / day (since all toilet flush water is household recycled wastewater or harvested rainwater) ~5 units / month (for daily usage of 370 watt pump motor connected to recycled water tank) *740 WATT PUMP MOTOR IS USED AS AN EXAMPLE ONLY *DATA AS PER BSES WEBSITE IV. CONCLUSION As shown in Table 1, the normal toilet requires 200 litres of potable government supply water or groundwater whereas the Ecoflush saves this water since all the flush water in this proposed system is recycled household 145 ELK Asia Pacific Journals – Special Issue wastewater or harvested rainwater. Additionally, a normal household consumes 22 units of electricity per month for daily usage of a 740 watt pump motor to daily pump hundreds of litres of fresh potable government supply water for the day’s use for toilet flushing. On the other hand, the Ecoflush system will only consume less than 5 units of electricity per month for daily usage of a 370 watt pump motor to pump the recycled wastewater from a storage tank into the toilet flush in the bathroom. Only a small 370 watt pump motor will suffice for the Ecoflush system because the head (vertical distance) to pump water is much less for the Ecoflush since the recycled wastewater storage tank will be in the house, whereas a large 740 watt pump motor is required in normal household systems because the head (vertical distance) to pump water is high since water is pumped from government supply pipes (or groundwater) to storage tanks on the roof. Thus the Ecoflush will save 200 litres of potable government supply water / day and 17 units of electricity per month for an average Indian household. Table 2 presents these figures for annual consumption. Proc. Of the Int. Conf: ARIMPIE-2015 This Ecoflush water and electricity saving toilet system can be an integral part of any government funded housing development program, whether it be for construction or renovation of new or existing government quarters or government funded household schemes. This Ecoflush wastewater recycling system will be an example of sustainable household water usage, which will save water and electricity for future generations to come. 25. References [1] [2] [3] [4] [5] [6] US Patent No. 7,118,677 US Patent No. 6,143,185 Patent Publication No. 20020066310 Patent Publication No. 2876202 Patent Publication No. 2001303649 Patent Publication No. 201128939 TABLE 2: ANNUAL WATER AND ENERGY CONSERVATION Water Saved Ecoflush Toilet Energy Saved ~73000 litres / ~204 units / annum annum Furthermore, this household wastewater recycling system is supplemented by rainwater harvesting, which is a cost-effective method for additional water gain in households. In normal households, potable water provided by the government comes to the household pipes after it is treated by government plants. This precious potable water is wasted in toilet flushing. The Ecoflush wastewater recyling system will not only save this potable water but will also save energy and government funds and expenditure incurred by government plants that treat water for household consumption. 146 ELK Asia Pacific Journals – Special Issue 25. EXPERIMENTAL INVESTIGATION OF ENHANCING THE COP OF VCRS SYSTEM BY USING COOLING TOWER Gourav Roy1* ,Taliv Hussain2, Rahul Wandra3 Department of Mechanical Engineering, Lovely Professional University Phagwara, Punjab (India) -144402 Email:
[email protected] Phone no: 08968749228 Abstract: During the hot days when sun light at its maximum intensity VCRS (water cooled condenser) consume more power to cool down the substance and also consume lots of water. As the standard VCRS (water cooled condenser) approach practical limits, experimental modification should be performed to increase the system efficiency and capacity. One possible means to increase the COP of VCRS (water cooled condenser) is by using cooling tower consist of single cellulose pad on it. In this paper experimental investigation in order to enhancing the COP of VCRS (water cooled condenser) that utilize single cellulose pad as the filling material of cooling tower. The cooling tower performance is improved due to good water wet ability of cellulose pad that cause a uniform water circulation over the entire surface of pads and a perfect contact between water and cooling air. A VCRS has been built with water cooled condenser. In first case water cooled condenser is used at ambient temperature 29°C and 32°C.There is increase in COP 4.69 to 4.67.Similarly in second case water cooled condenser is attached with cooling tower with single pad at an ambient temperature 29°C and 32°C, COP increase from 4.93 to 4.68. Keywords-Air cooled condenser, Water cooled condenser, vapour compression refrigeration system, evaporative cooling pad. Nomenclature-COP Coefficient of performance h1 Enthalpy of refrigerant at inlet of compressor in kj/kg Proc. Of the Int. Conf: ARIMPIE-2015 h2 Enthalpy of refrigerant at exit of compressor in kj/kg h3 Enthalpy of refrigerant at exit of the condenser kj/kg h4 Enthalpy of refrigerant at entry of evaporator in kj/kg mref Mass flow rate of refrigerant Qr Cooling effect Wc Compressor work T1 Suction temperature of refrigerant into the compressor T2 Discharge temperature of refrigerant into the compressor T3 Condenser outlet temperature of refrigerant T4 Outlet temperature of refrigerant from capillary tube I Inlet current V Inlet voltage I. INTRODUCTION The fruit of development would not reach to the common man until energy reached the last household of the country. In RAC the special focus is given on VCRS in order to improve the performance and cooling capacity of a system. The refusal to accept anything without testing and trail, the capacity to change previous conclusion in the face of new evidence, the reliance on observe fact this all is necessary. Special emphasis will be placed on equity in development of VCRS system, so that the benefit of technological growth reaches the majority of population, leading to an improved quality of life forever citizen of country. Our main focus how to increase the COP of VCRS system .Cooling tower is one of the appropriate method to improve the performance of water cooled condenser.In order to further improving COP, use cellulose pad within the cooling tower which helps to increase the COP. For two different ambient temperature 29°C and 32°C COP varies from 4.96 to 4.67 at water cooled condenser.Similarly in next case cooling tower with single pad at 29°C and 32°C respectively COP changes from 4.93 to 4.68. II. LITERATURE SURVEY Fouda and Melikyan et al. [1] A simplified mathematical model was used to 147 ELK Asia Pacific Journals – Special Issue discuss the heat and mass transfer between the air and water in a direct evaporative cooler. A comparison between the model results and the experimental results was presented. The results indicate that during a steady state condition, the cooling efficiency is decreased by increasing the inlet frontal air velocity, and increased by increasing the pad thickness. This is because the contact surface between water and air is increased. S.S. Hu, B.J. Huang et al. [2] conducted an experimental investigation on a split air conditioner having water cooled condenser. They developed a simple watercooled air conditioner utilizing a cooling tower with cellulose pad filling material to cool the water for condensing operation. The experimental investigation verified that the water-cooled condenser and cooling tower results in decreasing the power consumption of the compressor. Sreejith K et al. [3] Heat can be recovered by using the water-cooled condenser and the system can work as a waste heat recovery unit. The recovered heat from the condenser can be used for bathing, cleaning, laundry, dish washing etc. The modified system can be used both as a refrigerator and also as a water heater. Therefore by retrofitting a water cooled condenser it produce hot water and even reduce the utility bill of a small family. In this system the water-cooled condenser is designed as a tube in tube heat exchanger of overall length of 1m. It consists of an inlet for the cooling water and an exit for collecting the hot water. The hot water can be used instantly or it can be stored in a thermal storage tank for later use. Adarsh Mohan Dixit, Aditya Desai, Akshay Vyas et al.[4] They made setup of 1.5 ton air conditioner was constructed and tested in the present study. The experimental results show the coefficient of performance (COP) reaches 8.03 that are higher than the standard value (5.98) of those conventional residential split air conditioners. W.L Lee et al. [5] performed the experiments to study the effect of water cooled air conditioning systems in residential building in Hong Kong with outdoor at 35°C DBT. The test results showed that COP was increased by 14-20% as compared to the air- Proc. Of the Int. Conf: ARIMPIE-2015 cooled condenser which reduced the peak load in the month of July by 27%. Later in 2008 he also studied the performance of domestic water cooled air conditioning using tube-in-tube helical heat exchanger condenser. The outdoor condition was 33°C DBT and 68% RH. The mass flow rate of tap water was 5-8lt/min. An increase of 12-20% in COP was recorded. S.S.Hu et al. [6] studied the split type residential water cooled air conditioning system using cellulose pad to remove heat of the water immersed condenser. The experiment was done at an ambient condition of 35oC DBT and 27oC WBT, air velocity of 1.7m/sec and water flow rate of 5.1lt/min. The COP was increased from 2.96 to 3.45which is an increase of 17%. III. EXPERIMENTAL SETUP A VCRS system is build which consists of a single stage with the basic components i.e. evaporator, compressor, expansion device and condenser. A tank of ten liters is built and condenser is put in that tank and tank is filled with water as shown in the figures. A water circulation system including a small pump (15Watt), is put in the tank and the outlet of pump is connected to the cooling tower because the function of the pump is to transfer the hot water from the condenser tank in to the cooling tower where it is cooled a bucket. Water circulation rate is constant for all tests. Hot ambient water is passes over the evaporative media pad of the cooling tower and gets cooled and cooled water is collected in the tank which is located in the below of the cooling tower in the cooling tower tank second pump is installed, function of this pump is to transfer the cooled water from the cooling tower tank in to the condenser tank, it become a closed cycle in which hot water and cold water circulate. In cooling tower evaporative pad of thickness 2 inch is used. Here the capillary tube is used, made up of a copper tube of very small diameter. Capillary tube used as expansion device. The evaporator is used to reduce the pressure, dissipating heat and making liquid refrigerant to much cooler. 148 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 (Fig 3) Represent the close view of cooling tower which consist of cellulose pad. Fig 3:Cooling Tower Fig.1 Water Cooled condenser with cooling tower After calculated different parameter by using water cooled condenser, now condenser is attached to cooling tower as shown in (Fig.2). IV. EXPERIMENT RESULT AND DISCUSSION PARAMETERS Water Cooled condenser Water cooled condenser with cooling tower At At At At 29°C 32°C 29°C 32 °C UNIT Suction Pressure Psi 12 12 5 5 Discharge Psi 160 160 148 148 Condenser Inlet Degree 36.2 38.4 35.2 37.4 Temperature Celsius°C Condenser Outlet Degree 29.1 31.3 28.1 30.3 Temperature Celsius°C Compressor Inlet Degree 10.2 12.2 19.2 21.2 Temperature Celsius°C Compressor Outlet Degree 43.1 45.1 35.3 37.3 Temperature Celsius°C Evaporator Inlet Degree 20.1 19.4 21.3 20.5 Temperature Celsius°C Evaporator Outlet Degree -16.2 -15.2 -18.1 -17.4 Temperature Celsius°C 1.23 Pressure Fig.2 Water Cooled condenser with cooling tower Here the cooling tower performance is improved due to good water wet ability of cellulose pad that cause a uniform water circulation over the entire surface of pad and a perfect contact between water and cooling air. The cooling tower cool the warm water discharged from the condenser and feed the cooled water back to the condenser. They, thus reduce the demand of cooling water in system. Current I 0.68 1.42 0.63 Voltage V 210 200 210 200 149 ELK Asia Pacific Journals – Special Issue Table 1: Result of the experiment of water cooled condenser and water cooled condenser with cooling tower The given experiment was carried out at two different ambient temperature 29 °C and 32 °C respectively. In first case we calculate the COP of system with water cooled condenser and then same water cooled condenser is attached to cooling tower. While performing the experiment refrigerant and air remained constant in order to achieve steady state also current and voltage is constant for both the ambient temperature. Proc. Of the Int. Conf: ARIMPIE-2015 Fig 5: Pressure-Enthalpy diagram for water cooled condenser and water cooled condenser with cooling tower at 32°C V. CALCULATION AND RESULT While performing the experiment, the result obtained. Based on this result thermodynamic properties of refrigerant R134a are obtained at the different point of the system. In order to calculate the enthalpy, using the P-h chart of the refrigerant R134a and we are getting different parameter at air cooled condenser and water cooled condenser attached with cooling tower. a. Compressor Work Wc = V * I = mref* (h2 – h1) b. Mass flow rate of refrigerant mref c. Cooling effect produced Qr=mref* (h1 –h4) d. COP = Fig 4: Pressure-Enthalpy diagram for water cooled condenser and water cooled condenser with cooling tower at 29°C Where, h1 = enthalpy of refrigerant at inlet compressor in kj/kg(1) h2 = enthalpy of refrigerant at exit compressor in kj/kg (2) h3 = enthalpy of refrigerant at exit of condenser kj/kg (3) h4 = enthalpy of refrigerant at entry evaporator in kj/kg(4) Parameter Water Cooled condenser of of the of Water Cooled condenser with cooling tower 29 °C 32 °C 29 °C 32 °C COP 4.69 4.67 4.93 4.68 Compressor Work 142 280 132.6 246 Table 2: Result of the experiment at ambient air temperature 29°C and 32°C 150 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 again circulated at the water condenser where it act as cooling medium. From our experiment there is increase in COP of the system as we move from simple water condenser to water condenser with cooling tower which at 29°C is 5.11% and at 32°C is 0.21%. Also as the ambient temperature is increase compressor work is also increase in both the cases. AT 29°C compressor changes 7.02% and 32°C it is 13.82% when we cooling tower. REFERENCES Graph 1: Compressor work variation with ambient temperature Graph 2: cop variation with ambient temperature The above two graph represent variation of ambient temperature with compressor work and COP. As the ambient temperature increase from 29°C to 32°C the compressor work goes on increase in both case water condenser and water condenser with cooling tower. Similarly the ambient temperature increase COP of system decrease further decrease in cooling capacity. [1] A.Fouda and Z. Melikyan.A simplified model for analysis of heat and mass transfer in a direct evaporative cooler. Appl. Therm. Eng. 2011; 31: 932-936. [2] S.S. Hu, B.J. Huang, “Study of a high efficiency residential split water-cooled air conditioner”, Applied Thermal Engineering 25 (2005) 1599–1613. [3] Experimental Investigation of A Domestic Refrigerator Having water cooled condenser using various compressor oils, Sreejith K, Assistant Professor, Dept.Of Mechanical. [4] Improving efficiency of air conditioner by cellulose pad/International journal of engineering science & humanities ISSN 22503552. [5] Lee WL, Yik FWH. “A framework for formulating a performance based incentive rebate scale for the demand side energy management scheme for commercial buildings in Hong Kong” Application Energy, 2002;73:139–66 VI CONCLUSION The cooling tower concept is simple and easy to install in normal water cooled VCRS system. Cooling tower is used to cool down the hot water from condenser which is circulated with help of water pump. This cool water collect at the bottom of cooling tower from where it is 151 ELK Asia Pacific Journals – Special Issue 26. IMPROVEMENT IN THERMAL EFFICIENCY OF A CI ENGINE USING A WASTE HEAT RECOVERY TECHNIQUE Aashish Sharmaa, 1, Ajay Chauhana, Himanshu Nautiyalb, 2, Varunc, Pushpendra Kumar Sharmab a Lovely Professional University, Phagwara, Punjab, India b THDC Institute of Hydropower Engineering & Technology, Tehri, Uttarakhand, India c National Institute of Technology, Hamirpur, (HP) India 1
[email protected] [email protected] 2 Abstract— A big portion of the heat supplied to an internal combustion (IC) engine is not converted into work and wasted through the exhaust gases in surroundings. If this heat is recovered or used by some means then improvement can be obtained in engine’s overall efficiency. In the present work, an experimental work is carried out to study the effect of waste heat recovery of exhaust gas in a Compression Ignition (CI) engine. The results show that considerable reduction in engine fuel consumption can be obtained with the help of exhaust heat recovery through a heat exchanger. A significant amount of heat of exhaust gases can be recovered by vaporization of fuel using a heat exchanger. Keywords—engine; efficiency; ignition; heat; recovery I. INTRODUCTION Energy has become an indicator of economic growth and social development of a country. Generally human consume the energy from fossil fuels and use this energy in various sectors of domestic and industrial activities as well as Proc. Of the Int. Conf: ARIMPIE-2015 for their comfort. Almost all developing and developed countries in the world are dependent on fossil fuels to obtain energy but their contribution in problem of climate change has become a matter of great concern. Today the entire world is focusing on the proper and best use of fossil fuels so that the environmental problems associated with them can be reduced considerably. This has become a great interest for scientists and engineers to find out the suitable alternatives for using efficient use of fossil fuels and recovering heat so that wasted heat can be reduced. IC engines have become an integral part of all human and commercial activities in daily life and widely used in power generation, transportation and agricultural sectors. But today the need of demand reduction and low harmful emissions through the efficient engines is being increased. Advance technology has the major interest in recent years particularly in highly efficient IC engine. The IC engines have several applications and are commonly used in cars, aircrafts and boats etc [1]. But the problem of fuel crises due to their fast depletion nature, environmental impediments associated with them are putting a question mark in the using of IC engines in future. Therefore, it is important to think about the improvement of efficiency of IC engines. IC engines transform about 25% to 35% chemical energy into mechanical work. About 70% of total energy is wasted through exhaust gas, coolant and radiation [2]. Exhaust gas temperature is high due to combustion process inside the cylinder, which cause cylinder wall temperature get high and proper cooling is required to minimize the cylinder wall temperature. Several industrial activities and processes in various sectors requires considerable amount of heat energy which generally not utilized efficiently. The wasted heat energy from the industries is transferred into the surroundings in the form of unburned fuels, sensible heat discharge from drain water and through sensible and latent heat through exhaust gases discharge. If this wasted energy is recovered by some means, better results in the performance of engine can be obtained. So, there is a big scope to recover wasted heat energy from IC engine and use it in some other 152 ELK Asia Pacific Journals – Special Issue applications. The wasted heat energy can be recovered efficiently through the combustion equipment to utilize wasted fuel and through heat recovery equipment to reuse sensible and latent heat through exhaust gases. Several efforts have been expended to reuse the wasted heat during past decades. This work describes the utilization of waste heat which is coming through exhaust gas and the engine performance. II. LITERATURE REVIEW Waste energy from engine is normally a byproduct which is in form of heat. Energy is lost from the IC engine to the environment in the form of exhaust gas, cooling water, lubrication oil and radiation. Generally waste heat recovery is a technique, which enhance the performance of engine and can reduce the brake specific fuel consumption (bsfc) and consequently thermal efficiency is improved. Tahani et al. [3] showed the waste heat recovery from 12 lt. CI engine using organic Rankine cycle. In the study, two different configuration of organic Rankine cycle (ORC) for waste heat recovery from exhaust gas and coolant: preheat configuration and two stage configuration. An optimized result was given at different working fluids R-134a, R-123 and R245fa. The power generation and cycle thermal efficiency were maximized. Finally it was found that R-123 is the best working fluid which gave best performance and increase thermal efficiency by 11.73% and 13.56 % respectively in both configurations. It was also observed that preheating configuration has better result if R134a is used as working fluid in both configuration but preheat configuration was not sufficient to recover total heat due to mass flow rate limitation. Alberto Boretti [2] showed optimum speed power turbine to recover the exhaust heat of CI diesel and gas engine. This was done by using turbocharger and intercooler and improvement was shown in fuel conversion efficiency at optimum speed. The exhaust energy is recovered by the power turbine that operates at optimum speed. A by-pass and continuously variable transmission (CVT) link is used to crankshaft. Gear ratio between power turbine and crankshaft is replaced by CVT. Due to this advantage Proc. Of the Int. Conf: ARIMPIE-2015 power turbine decoupled from the speed of crank shaft. Chauhan [4] presented a review on recovery of waste heat in IC engine. The study discussed six technologies to recover the waste heat which has come from the exhaust gas of IC engines viz. turboelectric generator technique, organic Rankine cycle technique, six stroke cycle technique, new development in turbocharger technique and combination of these techniques. These techniques have some merits and demerits, but useful to recover waste heat from exhaust. Bibin et al. [1] carried out a study on waste heat recovery in a hybrid engine with supplementary combustion chamber. In this study waste heat was utilized by producing the electrical energy with the help of turbocharger. The waste heat is utilized to burn the additional amount of the fuel. The thermoelectric generator which was used in produces electrical energy. Finally energy was recovered by the combination of compressor and alternator that was coupled with the turbine. Kumar et al. [5] studied a waste heat recovery in IC engine using thermos-electric technology. In the study a heat exchanger and 18 thermoelectric generator modules were designed and tested in test rig and overall efficiency of an engine was improved by using waste heat. Thermoelectric module was used as a generator which was a solid state device that converts thermal energy into electrical energy from a temperature gradient. Its principle was based on Seebeck effect. Thermoelectric modules were selected on the basis of temperature differences between exhaust side and engine coolant side. Rashad et al. [6] studied a single cylinder diesel engine performance under recycling and conditioning of exhaust for air intake. In the study a single cylinder air cooled engine having 8.3 HP and running at 1500 rpm was tested at test rig for measuring parameters. The engine was operated in different conditions viz. increase O2 percentage in an open mode up to 30% and increase CO2 in inlet charge for close mode operation. The results showed that inlet charge 153 ELK Asia Pacific Journals – Special Issue leads to increase the rated brake power with increasing O2 percentage and decreases fuel consumption and increase brake mean effective pressure. CO2 presence in inlet charge show harmful effect on engine performance. A theoretical model was also presented to predict overall performance. Proc. Of the Int. Conf: ARIMPIE-2015 the self-made heat exchanger. Copper tube is use in heat exchanger for the heat recovery and flow is parallel flow in the shell and tube heat exchanger. III. EXPERIMENTATION After the combustion process in IC engines, efficiency of engine is low due to high amount of heat losses. This heat loss is either by the exhaust gas or coolant. So there are various parameters that affect the thermal efficiency and bsfc of the engine. Direct injection and indirect injection are the injection methods that affect the performance of a CI engine. Many assumptions and operating factor affect the performance of the engine. Compression ratio: mechanical efficiency reduces on increasing the compression ratio due to increase in weight of reciprocating parts. Engine speed: on increasing the engine speed, loss of the heat during compression decreases. Engine output: with an increase in engine output the air fuel ratio decreases. Injection timing: for higher ignition advance pressure and temperature at the beginning of injection are lower. Quality of the fuel: lower self-ignition temperature must be use for better performance. Intake temperature: on increasing the intake temperature, compressed air temperature increase causes delay period reduces. Intake pressure: on increasing the intake pressure reduces the auto ignition temperature. So assumptions are based on these factors that can increase the performance of engine. The objective of the present work is to study the recovery of waste heat exhaust gas by vaporization of fuel through a small heat exchanger. An amount of fuel is vaporized by The experiment is conducted on modified single cylinder water cooled engine that runs at 1500 rpm having 5.2 kW power. The experimental setup is shown in Fig 1 and test rig specification is given in Table 1. To conduct the experiment, firstly a heat exchanger is selected for waste heat recovery. The diameter of the heat exchanger is optimized and other parameters viz. length and thickness of heat exchanger are found out. Copper pipes are used inside the heat exchanger of length 2000 mm. TABLE 1: ENGINE SPECIFICATIONS Manufacture Kirloskar Oil Engine Ltd., Pune Engine Single Cylinder. 4-Stroke, water cooled diesel engine Bore 87.5 mm Stroke 110 mm Comp. Ratio 17.5 Capacity 661cc (0.661 Ltrs) Power 5.2 kW at 1500 rpm Sp. Fuel 220 gms/kW-hr Combustion (0.22kg/kW-hr) 154 ELK Asia Pacific Journals – Special Issue RPM 1500 rpm BHP@1500 rpm 5.2 kW Cooling System Water Cooled Experiment is done on the test rig. The engine which is used in this experiment is run on dual mode: one without diesel vapor mixture and another with diesel vapor mixture. Firstly all readings without diesel vapor mixture are measured. The supply valve of water for engine is open first. Now fuel supply is started and time taken is measured with the help of digital stop watch for the fuel consumption. The first load is set and first reading of exhaust temp at 27° crank angle injection timing on computer through the thermocouple noted down. Time is taken for the first 20 cc of fuel. This procedure continues for next load and found all reading for exhaust gas temperature without diesel vapor mixture at 27° crank angle injection timing. Similarly all procedure is continued at 30° crank angle injection timing and 27° crank angle injection timing with direct port supply (DPS). Now experiment testing is done with the diesel vapor fuel mixture. A heat exchanger is used to this process. A constant supply of exhaust gas is used through the differential valve. Only 4 % of exhaust gas is used in this process. Now the fuel supply is started to the heat exchanger this fuel is vaporized by the heat exchanger. Again time taken is measured with the help of stop watch. Now diesel vapor mixture is used in intake system which is supplied by the accumulator. Again the loads are set and measured all reading at 27° crank angle injection timing. Similarly all readings are measured at 30° crank angle injection timing and 27° crank angle injection timing with DPS. A heat exchanger-accumulator mechanism is used to vaporize the fuel and catalytic cracking. Accumulator has 20 mm inner shell diameter and 50 mm of outer shell diameter. Accumulator is mounted on intake manifold to supply the diesel fuel in vapor form and it is mixed with air into intake system. Fig 2 shows the schematic of heat exchanger and its specifications are presented in Table 2. Proc. Of the Int. Conf: ARIMPIE-2015 Exhaust Gas out Diesel in Diesel out Exhaust Gas in Fig 2: Schematic of heat exchanger TABLE 2: SPECIFICATIONS OF HEAT EXCHANGER S. No. 1 2 3 4 5 Particular Dimension (mm) 420 280 the 2 Diameter Length Thickness of cylinder Diameter of the 12 copper pipe Length of the copper 2000 pipe IV. DATA ANALYSIS The engine is tested at different loads from 5 kg to 30 kg at different time intervals, by connecting a thermocouple at the engine’s exhaust. Heat loss through the exhaust gas from internal combustion is calculated as follows. The following data were assumed for the study [7] Volumetric efficiency is 0.8 to 0.9 Density of diesel fuel is 0.71 to 0.85 gm/cc Calorific value of diesel is 42 to 45 MJ/kg Density of vapor fuel is 1.167 kg/m3 Specific heat of exhaust gas is 1.1-1.25 KJ/kg °K Exhaust heat loss through diesel engine: Compression ratio (r): 155 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 r = (Vc+Vs) / Vc Vc = 4 × 10 -5 m3 TABLE 4: TIME FOR 20 CC OF FUEL Total volume (Vt) = Vc + Vs =7.01 × 10-4 m3 Load (kg) Time (sec) Mass flow rate of fuel (on the basis of specific fuel consumption) ṁf 0 84 5 76 10 62 15 53 20 47 25 34 30 26 s.f.c = ṁf / power ṁf = 0.3177 gms/sec Volume rate = swept volume × speed Volume rate (V) = Vs × N = 8.262 × 10-3 m3/ sec Volumetric efficiency (v) a. Design for the heat exchanger Mass flow rate of exhaust gas which is flowing in heat exchanger, we are using only 4% of mass flow rate of total exhaust gas. Table 5 and Table 6 show the mass flow rate of exhaust gas and fuel at different loads. v = volume of air/ swept volume v = ṁa / ρa × n × Vs ṁa = v × ρa × n × Vs = 8.625 gm/sec TABLE 5: MASS FLOW RATE OF EXHAUST GAS AT DIFFERENT LOADS Mass flow rate of exhaust gas (ṁE) ṁE = ṁf + ṁa= 8.9427 × 10-3 kg/ sec Load (kg) Mass flow rate (kJ/s) 0 3.5 × 10-4 Table 3 show the exhaust temperature measurement by thermocouple at different loads and Table 4 shows the time for 20 cc of fuel. 5 3.6 × 10-4 10 3.8 × 10-4 TABLE 3: EXHAUST MEASUREMENT 15 3.9 × 10-4 20 4.0 × 10-4 25 4.4 × 10-4 30 4.79 × 10-4 Heat loss in exhaust gas (QE) = ṁE × Cp × T = 4.13 kJ/sec (or kW) Load (kg) 0 5 10 15 20 25 30 Exhaust temp. (0C) 300 340 380 395 405 430 460 Voltage (V) 240 240 240 240 240 240 240 TEMPERATURE Current (A) 5 8 12.5 17.5 22 26 Heat loss (kJ/hr) 12892.5 13923.9 15986.7 17533.8 19080.9 20628 21146.4 TABLE 6: MASS FLOW RATE OF FUEL AT DIFFERENT LOADS 156 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Load (kg) Mass flow rate (kJ/s) 15 355 0 0.053 20 370 5 0.06 25 385 10 0.068 30 400 15 0.080 20 0.081 25 0.09 30 0.095 Inlet temperature of cold fluid (Tc1) is 30° C. Now equation for heat balance is: Heat gain by cold fluid fluid = ṁc × Cc × ∆Tlm = heat loss by hot ṁh × Ch × ∆Tlm Table 7 and Table 8 show the inlet temperature of hot fluid Th1 and outlet temperature of hot fluid Th2 . From these two tables we can design the heat exchanger. Rate of heat transfer (Q) = ṁc × Cc × ∆T TABLE 7: INLET TEMPERATURE OF HOT FLUID LMTD: Load (kg) Temperature (0 C) 0 300 5 340 10 380 15 395 20 405 25 430 30 460 Tc2 = 330K = 3.9kW ln[(Th2 – Tc2) / (Th1 – Tc1)] /Q)* [(Th2 – Th1) + (Tc1 – Tc2)] = (UA A = 0.1266048 m2 Area of the tube, At = ṁh / ρv = 1.3682 *10-3 m2 At = πd2 / 4 But, d = 0.012 m Length of the tube, A = πdL L = 0.28 m TABLE 8: OUTLET TEMPERATURE OF HOT FLUID 0 Load (kg) Temperature ( C) 0 270 5 300 10 335 Diameter of the heat exchanger, A = πD2 / 4 D = 0.4015m V. RESULTS & DISCUSSIONS As performance characteristics are given by the brake thermal efficiency and bsfc. Thus results obtained from the experiment shows the 157 ELK Asia Pacific Journals – Special Issue variation of brake thermal efficiency and bsfc with respect to brake power. a. Brake Thermal Efficiency Fig 3 shows the variation of brake thermal efficiency without diesel vapor mixture and with diesel vapor mixture at 27° crank angle for injection timing. This graph shows the variation in brake thermal efficiency at various loads i.e. with brake power at 50%, 75% and 100% load conditions. The brake power is 2.388 kW with 50% load at 27° crank angle injection timing, corresponding to these values, the brake thermal efficiency without diesel vapor mixture is 0.238 and with diesel vapor mixture are 0.262. Also the brake powers were 3.544 and 4.776 at 75 % and 100% load respectively, corresponding to these values, the brake thermal efficiencies without diesel vapor mixture are 0.251 and 0.252 and with diesel vapor mixture brake thermal efficiency are 0.283 and 0.290 respectively. This shows 10% increment with 50% load, 13% increment with 75% load and 15 % increment with 100% load in brake thermal efficiency are obtained when diesel vapor mixture is used. Fig 3: Variation in brake thermal efficiency without diesel vapor mixture and with diesel vapor mixture at 27° crank angle injection timing Proc. Of the Int. Conf: ARIMPIE-2015 Fig 4: Variation in brake thermal efficiency without diesel vapor mixture and with diesel vapor mixture at 30° crank angle injection timing Fig 4 shows the graph of brake thermal efficiency without diesel vapor mixture and with diesel vapor mixture at 30° crank angle injection timing. This graph again shows the variation in brake thermal efficiency with brake power at 50%, 75% and 100% load conditions. The brake power is 2.6196 kW with 50% load at 30° crank angle injection timing, corresponding to these values, the brake thermal efficiency without diesel vapor mixture is 0.229 and with diesel vapor mixture is 0.252. The brake powers at 75% and 100% load are 3.542 and 4.7426 respectively, corresponding to these values, the brake thermal efficiencies without diesel vapor mixture are 0.2301 and 0.240 and with diesel vapor mixture brake thermal efficiency are 0.2581 and 0.272 respectively. This shows 10.19% increment with 50% load, 12.12% increment with 75% load and 13.6% increment with 100% load in brake thermal efficiencies with use of diesel vapor mixture. Similarly graph plotted at 27° crank angle injection timing with direct port supply (DPS) in Fig 5. The brake power is 2.388 kW with 50% load at 27° crank angle injection timing with DPS, thus the brake thermal efficiency without diesel vapor mixture is 0.245 and with diesel vapor mixture is 0.279. The brake powers are 3.544 and 4.776 with 75 % and 100% load respectively at 27° crank angle injection timing with DPS, giving the brake thermal efficiencies without diesel vapor mixture of 0.249 and 0.259 and with diesel vapor mixture 0.281 and 0.31 respectively. Hence showing 14% increment at 50% load, 12.17% increment at 75% load and 19.8 % increment at 100% load in brake thermal efficiencies when diesel vapor mixture at 270 crank angle injection timing with DPS is used. 158 ELK Asia Pacific Journals – Special Issue Fig 5: Variation in brake thermal efficiency without diesel vapor mixture and with diesel vapor mixture at 27° crank angle injection timing with DPS Proc. Of the Int. Conf: ARIMPIE-2015 Fig 6: Variation in bsfc at 27° crank angle injection timing At 27° injection timing with DPS, the increment in brake thermal efficiency is more because of charge potential is better than to others. There is a fine mixing of charges inside the engine cylinder at this injection timing and reduce the delay period for combustion causes peak pressure increase and less fuel consumption achieved. b. Brake Specific Fuel Consumption Same as the brake thermal efficiency, brake specific fuel consumption was shown in Fig 6. These graphs are plotted at 27°, 30° and 27° with DPS injection timing. Fig 6 shows the graph of bsfc without diesel vapor mixture and with diesel vapor mixture at 27° crank angle injection timing. This graph shows the variation in bsfc with brake power at 50%, 75% and 100% load conditions. The brake power is 2.388 kW with 50% load at 27° crank angle injection timing, corresponds to these values, bsfc without diesel vapor mixture is 0.38 and with diesel vapor mixture is 0.31. The brake powers are 3.544 and 4.776 at 75 % and 100% load respectively and the bsfc without diesel vapor mixture are 0.33 and 0.32 and with diesel vapor mixture bfsc are 0.305 and 0.301 respectively. Hence 5.9% reduction of bsfc at full load condition when with diesel vapor mixture is achieved. Fig 7: Variation in bsfc at 30° crank angle injection timing Fig 7 shows the graph bsfc without diesel vapor mixture and with diesel vapor mixture at 30° crank angle injection timing. The brake power is 2.6196 kW with 50% load at 30° crank angle injection timing which gives the bsfc without diesel vapor mixture of 0.359 and with diesel vapor mixture of 0.3295. The brake powers are 3.542 and 4.742 at 75 % and 100% load respectively, corresponding these valves, the bsfc without diesel vapor mixture are 0.352 and 0.345 and with diesel vapor mixture bfsc are 0.32 and 0.292 respectively, hence showing 15% reduction in the bsfc at full load condition with diesel vapor mixture. Fig 8 shows the graph of bsfc without diesel vapor mixture and with diesel vapor mixture at 27° crank angle injection timing with dps. This graph shows the variation in bsfc with brake power at 50%, 75% and 100% load conditions. The brake power is 2.388 kW with 50% load at 27°crank angle injection timing with dps, the bsfc without diesel vapor mixture is 0.378 and with diesel vapor mixture is 0.27. The brake 159 ELK Asia Pacific Journals – Special Issue powers are 3.544 and 4.776 with 75 % and 100% load respectively, corresponds to the bsfc without diesel vapor mixture of 0.339 and 0.302 and with diesel vapor mixture bfsc of 0.263 and 0.260 respectively, hence giving 13.9 % reduction in the bsfc at full load condition with diesel vapor mixture. Proc. Of the Int. Conf: ARIMPIE-2015 optimum condition for the brake specific fuel consumption. This shows the advantage of combustion of diesel vapor with the recovery of heat from exhaust gases that can be used to obtain less fuel consumption and increasing thermal efficiency at decrease load condition. References So bsfc at 27°, 30° and 27° injection timing is calculated with dps from the graphs the optimum condition is found at 30° crank angle injection timing. At this condition there is the maximum reduction of 15% in bsfc. [1] [2] [3] [4] Fig 8: Variation in bsfc at 27° crank angle injection timing with DPS VI. CONCLUSION The heat which is considered as waste heat come from the exhaust gases can be utilized by vaporization of diesel. This evaporated fuel mix with the intake air and burns completely. It reduces the delay period which causes increase in combustion pressure and develops more power. Due to the proper mixing, the charge burns completely and there is no unburnt hydro carbon present in exhaust thereby reducing the emissions. Specific heat of fuel increases due to vaporizing and bsfc is decreases significantly. The fuel ignites at multiple points and no flame propagates in combustion chamber thereby perfect combustion takes place causing less emission. The percentage increment in brake thermal efficiency with diesel vapor mixture is 15% at full load 27° injection timing, 13% at 30° injection timing and 19.8% for 27° DPS. Thermal efficiency is high in case of 27° injection timing with DPS due to perfect mixing and air-fuel ratio. It is also observed that brake specific fuel consumption reduces by 5.44% for 27°, 15% for 30° and 14% for 27° with DPS as the load increases. So 30° injection timing is the [5] [6] [7] Bibin, Y. Kojima, K. Takahashi, Baba T., Ibaraki S., Takahashi T., Study on Maximizing Exergy in Automotive Engines, SAE Int. Publication 2012-01-0257, 2007. Boretti A, Optimum Speed Power Turbine to Recover the Exhaust Energy of Compression Ignition Diesel and Gas Engines SAE Int. Publication 2012-01-0537 (2012). Tahani, E. Bellos A, Kakaras E., A comprehensive study on waste heat recovery by organic rankine cycle, June 26-29, 2013, Perugia, Italy. Chauhan V, A Review of research in mechanical engineering on recovery of waste heat in internal combustion engine, International Journal Of Research In Engineering & Applied Sciences, 2012, 2 (12) 2249-3905. Kumar R., Sonthalia A, Goel R, Experimental study on waste heat recovery from an internal combustion engine using thermoelectric technology, Thermal Science, 2011, 15 (4), 1011-22. Rashad AM, Investigation of a single cylinder diesel engine performance under recycling and conditioning of exhaust for air intake, Transactions of the Japan Society of Mechanical Engineers, Part B 70 (689) (2009) 292–299. Xuejun H, Deli G., Analysis of Exhaust Gas Waste Heat Recovery and Pollution Processing for Z12V190 Diesel Engine, Maxwell Scientific Organization, Res. J. Appl. Sci. Eng. Technol., 2012, 4, 1604-11. 160 ELK Asia Pacific Journals – Special Issue 27. MOTION CONTROL SYSTEM OF DC MOTOR DRIVE THROUGH PID CONTROL Pragya Singh Mechanical & Automation Engineering Department Amity University Sec-125, Noida, Uttar Pradesh India
[email protected] Hemant Chouhan Mechanical & Automation Engineering Department Amity University Sec-125, Noida, Uttar Pradesh, India
[email protected] Abstract: The proposed work presents the motion control of DC motor which is an indispensable feature to be taken into considerations for many industrial applications. The work deals with the comparison between manual control to a simple on/off control and a PID control. The results are interpreted and compared through responses obtained by MATLAB software. The response of the dc motor through the graphs show that the open loop condition has a time delay in the system’s performance and implementation of ON/OFF controller improves the results to an extent, while the PID controller finds its path in eliminating the error and gives the most appropriate result. Keywords – DC motor drive, open and closed loop, PID controller I. INTRODUCTION An electric drive is an electromechanical system that employs an electric motor as a prime mover to control the motion of different machines and mechanisms. On account of increased competition and detailed transparency of practical applications, there is a requirement of high performance drives which should be efficient in all the fields required for its performance apart from just fulfilling the industrial requirements. To match such kind of expectations from the industry,a high Proc. Of the Int. Conf: ARIMPIE-2015 performance drive should be able to maintain the dynamic speed command and load regulating responses. Direct current motors find an immense use in variable speed controls and position control system where good dynamic response and steady state response is required. Robotic drives, printers, machine tools, rolling mills, textile and paper industries are a good source of DC Motor drive applicant. The electric drive holds features like adaption of control characteristics to the application, easy and simple speed control methods, high efficiency, wide range of power, speed and torque ratings. A typical electric drive system includes a controller, a transmission system, an electric motor and a driven load. From control system perspective, DC motor can be taken as a Single Input Single Output (SISO) system having speed characteristics which suits well with all mechanical loads. This characteristic makes the DC motor applicable in all the controllable devices and provides good adjustments to the terminal voltage. This emblematic feature makes the DC motor a good choice over other driver system and the speed control of these motors can also be enhanced.[1 , 2] For speed control of dc motor drive a closed loop system is employed which calculates the error at the output and gives it back to the input of the actuator. This makes the output of the DC motor as totally desirable for the system and no differences occur at the receiving end.There are many methods available for maintaining the speed of DC motor but Proportional-IntegralDerivative (PID)Controller is the most reliable and commonly used in all the industrial processes. The output of the motor is regulated and estimated by PID for the proper results. [3] 161 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Fig.1: Block diagram of a closed loop control of a DC motor drive The speed of separately excited DC motor can be regulated as per the required speed by the implementation of the PID controller. II(a) MATHEMATICAL MODELLING OF DC MOTOR A separately excited DC motor consists of a field and armature winding each of them with separated supply. Field winding is used to generate flux and armature current is drawn by the commutator and brush segment. The field current excites the motor and as a result armature current flows into the circuit. Therefore, the motor develops a Back EMF and a torque to balance the load torque at particular speed level. [2] Td = Jdω/dt + TL …(3) Eb = Kφω …(4) Td= KφIa …(5) Applying Laplace transform to above equations, we get, Ia(s)=Va-Eb/Ra+La(s) = (Va-Kφω)/(Ra(1+La/Ras)) …(6) also, ω(s) = (Td-TL) /Js=(KφIa- TL )/Js …(7) Ta= La/Ra represents armature time constant and Tm = JRa/(Kφ)2 represents electromechanical constant and replacing Kφ by Km. By applying block reduction method to the block diagram of motor model, the transfer function can be obtained as: ω(s)/va(s) = [(kΦ/Ra)/(Js(1+sTa) /1+(K2Φ2)/ Js(1+Ta) ] …(8) further simplifying the equation we get, ω(s)/Va(s) …(9) = (1/Km)/(1+sTm)(1+sTa) Thus, it is observed that two time constants i.e. Tm and Ta of the above system transfer function(T/F) are taken for account for the response of system.[1] Fig2: Equivalent circuit of a DC Motor Applying Kirchhoff’s law to the Equivalent circuit Va=IaRa + La di/dt + Eb …(1) Td=Jdω/dt + Bω + TL …(2) Where Va = armature voltage; Eb = motor back EMF; Ia= armature current; Ra = armature resistance; La = armature inductance; TL = Load Torque; Td = developed Torque; J = moment of inertia; B = friction co-effecient of motor; ω= angular velocity Table 1: Showing useful ratings of DC Motor as required Since, field current If is constant, the flux will be constant. therefore, the emf induced and torque developed can be obtained as : 162 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 The motor considered for the experimental response is Maxon DC Motor with operating specifications are shown in table1. III.RESULTS AND DISCUSSION II(b) CURRENT CONTROL LOOP Initially, when only the motor is run and the output is derived with no closed loop added to the system, the initial response of the system will be very slow due to the starting torque and armature resistance. The desired output is achieved after a delay of few seconds. The presence of electromechanical windings leads to generate resistance at the commence, but the speed controller leads off at that very moment. Initially, due to the electromechanical constant, there is no output as speed from the motor. Hence, III (a) OPEN LOOP SYSTEM the feedback output voltage Va is maximum and there is a large amount of current flow in the motor due to zero Back EMF.This may lead to reach maximimum rated motor current and would damage the motor. Therfore, arises the requirement of a control loop to regulate the armatue current in order to save the motor.[2] Whenever there is an increase in current from the reference current as denoted by the speed controller, the armature current rises and the error in the speed output is calculated, this leads to lower the acceleration and torque required for the DC motor. So, the error generated at the output is fedback to the speed controller input to eventually generate the desired amount of input from the reference position.[3 , 4] II(c) PID CONTROLLER A proportional-Integral-Derivative controller is a feedback loop controller which observes the error generated and calculates the required amount of input to be allowed to be fed to the system. The controller also estimates the error and gives the required amount of the input value to be needed on calculation of the previous records. The controller attempts to minimize the error by adjusting the process through use of manipulated variable. The PID controller algorithm consists of three termsP(proportional), I- (Integral), D-(Derivative). P depends on the present error, I is the integation of the past observed values, and D is the prediction of future errors based on current rate of change. The error can be defined as the difference in the desired output and the observed output.[3 , 6] Fig:3: Time motor Response of Open loop of DC In Fig(3). it can be seen that the final output is achieved successfully, but the time required for the system to reach the rated speed is 2 seconds. This time consumption of the system leads to show the system response as very slow. This result embarks for some solution which would make the system respond quickly with better results. III(b) FEEDBACK LOOP (1) ON/OFF CONTROLLER A feedback loop is applied to the DC Motor which takes the output of the system and gives the input accordingly. When the system starts at first, the speed of the rotor rises to the required level. The speed rises continuously despite the level of maxima. 163 ELK Asia Pacific Journals – Special Issue The controller calculates the difference in the output and switches off the current. The motor is stopped and the speed starts decreasing. The velocity of the shaft starts dropping to the required level and keeps dropping further. Again, the controller calculates the difference between the outputs and switches on the motor. Hence, the speed starts rising again. This is repeated each time the controller senses an imbalance in the output desired. Fig4. shows the response of the motor with an ON/OFF controller implied in the feedback loop. This response goes with many ups and downs and does not remain constant at the required level, though it manages to maintain the output with a short span of change in speed. Here,the need arises of something that manages to calculate the error and tries to maintain the output at constant level. Proc. Of the Int. Conf: ARIMPIE-2015 The response of the controller can be described in terms of responsiveness of the system to the error generated and to the degree to which the controller overshooots the setpoint. The controller describes the error in rise time, time delay and percentage overshoot of the system. The controller can be prepared as per the requirement of the system according to the error to be improved. There can be many combinations set by the P,I,D terms viz., P only ,PI, PD or PID controller according to the need of the system. start run the dc motor speed control model for parameters calculate the[ Kp,Ki,Kd] parameters calculate the equation of PID by implementing the parameters Fig4: Time response for on/off controller (2) PID CONTROLLER PID comprises of Proportional-IntegralDerivative terms in the system the system ought to be free from errors and behaves as in an ideal condition. The PID works with an algorithm process which has various instructions and conditions to follow. The main advantage of using PID is that it allows for consideration of easily constuctable bounded initial conditions. By tuning the three parameters in the algorithm, the controller can provide control action for the speed of the DC motor.[3 , 5 , 6] no desired output yes end Fig.5: Flow chart of a PID algorithm The application of PID parameters ameliorates the response of the dc motor and helps in achieving the right output. 164 ELK Asia Pacific Journals – Special Issue Fig 6: Time response for ‘P only’ controller Fig. 7: Time response for ‘PD’ controller Proc. Of the Int. Conf: ARIMPIE-2015 Fig 9 : Time response for ideal PID From the responses shown for various parameters of PID controller, it can be observed that the rise time which means the starting torque of the motor reduces to a minimum value giving a sharp rise at the beginning. When ‘P only’ controller is applied, the rise time reduces and simultaneously the overshoot of the system increases to 30% from the reference line(Fig.6) .The variations settles at 1.8seconds. That means the armature voltage of the system rises to a very high extent. This rise of armature voltage can harm the dc motor by burning of coils.[2] So,a differential controller was needed to be adjusted along with the proportional controller which would suppress the exces of voltage applied to the dc motor. This enables to successfully chop the extra overshoot of the system. Although, the overshoot and rise time have been improved(Fig.7) to almost 10% of the desired value and settling time is 1.2 seconds, yet there are many displacements while settling down to the constant line. Fig 8 : Time response for ‘PID’ controller An integral controller to the system is applied which leads to a subtle time response of the system with desired output. In (Fig.8), it can be seen that the response of the system is accurate to almost at the reference line.The overshoot is less than 5% and settling time reduces to 0.8 seconds. Physically, there can be some difference in the output of the system as compared to the theoretical values 165 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 evolved, but they can be neglected as the differnce will be quite small and would not be visible with physical observance. parameters to a value resulting in a perfect solution is an important step and may require a number of iterations before achieving the desired outcome. Fig.9, shows the ideal response of the DC Motor through PID. There is no overshoot for the system and the settling time is 0.2 seconds. The parameters need to be calculated for every system to achieve the desired response from the control system. The values of the prameters are adjusted as per the specification of the system to be controlled. The system can achieve its desired result as specified. A further study needs to be done for incorporation of optimization techniques in deriving the parameters of PID that will help in achieving the desired value of speed of DC Motor in real time. References: Parameters Symbol Values Remark Proportional Kp 300 Improves time Integral Ki 300 Improves settling time Derivative Kd 200 Improves overshoot Table 2: Properties of PID parameters IV. CONCLUSION The performance of DC motor has been studied and parameters for PID controller are obtained. The open loop response gave the factors that needed to be improved through feedback loop. Application of on/off controller encourages to reach to a much closer value as it is not found to be satisfactory solution to the process. The PID controller added to the system can estimate the error and control the input of the system preventing from delay and wastage simultaneously. It is observed that for any system to be stable, PID can be a good solution. However, it should be noted that setting the P,I and D Rise [1] Anguluri Rajshekhar,et.al.2013. Design of intelligent speed controller for chopper fed DC Motor drive using opposition based artificial bee colony algorithm, Engineering aplication of artificial intelligence, Elsevier. [2] Subhramanyam, k, 2000. Electric drive concepts and application. Tata Mcgraw hill, New Delhi. [3]Das, et.al.2012.A novel fractional order fuzzy PID controller and its optimal time domain tuning based on integral performance indices.Eng appl.Artificial Intelligence. [4]Zhihuan Chen,et.al.2014. Design of a fractional order PID controller for hydraulic turbine regulating system using chaotic non-dominated sorting genetic algorithm II, energy conversion and management. Elsevier. [5]Guo-qiang Zeng, et.al.2014.Design of multivariable PID controllers using real coded population based external ops…,timization.Elsevier. [6]SergeiS.Mikhalevich, et.al.2014.Development of a tunable method for PID controller to achieve the desired phase margin. 166 ELK Asia Pacific Journals – Special Issue 28. EFFECT OF SUBCOOLING IN VCRS AS COMPARED TO SIMPLE VCRS SYSTEM Taliv Hussain1,Arjun Sharma 2,Navin3,Rahul Wandra4,Gaurav Roy5 Department of Mechanical Engineering, Lovely Professional University Phagwara, Punjab (India) -144402 Email:
[email protected] Phone no: 08283836492 Abstract:-Decreasing the consumption of power in a vapour compression air conditioning system with increase in refrigeration effect and reduction of compressor work is a major concern and challenging problem especially in the area where extreme weather conditions of about 50°C exists. This extreme weather condition not only decreases the performance of an air condenser but also increases the electrical power consumption. In this paper we have analysed subcooling by heat exchanger, air cooled condenser and formulate the performance of each on VCRS system. A set-up of vapour compression air conditioning has been built and is paired with the heat exchanger and normal air condenser. Both the Heat exchanger and air condenser are connected in series.The effect of these two on the cycle performance at different ambient conditions have been measured. Experimental results show that the use of subcooling by heat exchanger compared with simple vapour compression system will improve the COP. The COP of subcooled VCRS is 3.99 where as the COP of simple VCRS is 3.Thus the COP increase is about 33.3% in subcooled vapour compression refrigeration system as compare to simple vapour compression refrigeration system. Keywords: Vapour compression refrigeration system, COP, subcooling. Proc. Of the Int. Conf: ARIMPIE-2015 energy(wind) sources but during last few decade, there has been rapid increase in demand of energy consumption because of increasing population .The resulting impact of Such energy consumption trend on the local environment has been massive with far-reaching consequences which can be seen in the form of rising global temperature and sea level .India became the world's third largest producer of electricity in the year 2013 with 4.8% global share in electricity generation which means more burning of fossil fuels as 70% of India’s energy generation is from fossil fuel with coal accounting for 40% followed by crude oil and natural gas. So it has become indispensable thing for today’s government to find energy efficient systems which will consume less power for the same amount of work. In this project we have concentrated our study on subcooling by heat exchanger (HX) ,and simple air conditioning systems(VCRS) using R134a(tetraflouro ethane) as refrigerant and found out experimentally the performance improvement in COP and power consumption using comparison between subcooled by heat exchanger(HX) and air cooled air conditioning systems .Typically Air cooled condenser are commonly used in almost all residential buildings and commercial offices. Increase in average temperature due to global warming is also increasing the demand of these air conditioners. With the increase in ambient air temperature (~30-46°C) there is a drop in COP of most of air cooled air conditioners units by about 35-45% which further increases the electricity consumption. Further the use of heat exchangers is widespread in commercial refrigeration. The heat exchangers are often employed as a means for protecting system components, by helping to ensure single-phase liquid to the expansion device and single-phase vapour to the compressor. As a result of employing this intra-cycle heat exchange, the high pressure refrigerant is subcooled at the expense of superheating the vapour entering the compressor. I INTRODUCTION II LITERATURE REVIEW Until the beginning of the nineteen century, man’s energy sources were mainly human muscle power and some other non-conventional Groseclose et al. [1954] showed that the cost of the water-cooled condensers with cooling towers and the evaporative cooling condensers were 167 ELK Asia Pacific Journals – Special Issue almost the same. Nevertheless, the conventional water-cooled condensers involved a cooling tower, which also imply a larger installation space and extra power for fan and pump .Gosney [1982] dimensionless equations for COP and volumetric-capacity effectiveness of the internal heat exchange. A thorough" discussion of liquidsubcooling and vapor-superheating effects .Webb [1984] developed a unified theoretical treatment of evaporative systems: cooling towers, evaporative coolers and evaporative condensers. His model considered the effect of the variation in temperature of the deluge water in an evaporative cooler, but stated that for an evaporative condenser the film temperature remains essentially constant due to the fact that the variation in the refrigerant temperature is negligibly small. McLinden [1990] performed analysis of llsl-hx cycles employing a semitheoretical cycle simulation model, which included representation for the evaporator and condenser, and temperature profile of the sink and source heat transfer fluids. He concluded that fluids having a high vapour heat capacity can simultaneously achieve high capacity and efficiency. presented simulation results showing different relative rankings of refrigerants studied depending on the cycle used for performance comparison (llsl-hx or reversed Rankine cycle).P.A. Domanski and D.A. Didion [1992] paper presents a theoretical evaluation of the performance effects resulting from the installation of a liquid line/ suction line heat exchanger (llsl·hx). It examines cycle the parameters and refrigerant thermodynamic properties that determine whether the installation results in improvement of COP and volumetric capacity. The study showed that the benefit of application of the Jlsl-hx depends on a combination of operating conditions and fluid properties , heat capacity, latent heat, and coefficient of thermal expansion with heat capacity being the most influential property. Fluids that perform well in the basic cycle are marginally affected by the llsl-hx, and the impact on the Coefficient of Performance and volumetric capacity may be either positive or negative. Fluids performing poorly in the basic cycle benefit from the llsl·hx installation through increase of the Coefficient of Performance and volumetric capacity .Linton et al. [1992] Proc. Of the Int. Conf: ARIMPIE-2015 experimentally investigated the effect of condenser liquid subcooling on a refrigeration system performance. Results showed that the cooling COP and refrigeration capacity of all three refrigerants benefited from subcooling increase (from 6°C to 18°C): R134a (12.5%), R12 (10.5%) and R152a (10%), while condensing temperature was kept artificially constant. Subcooling has also been subject of publications related to automotive air conditioners. These systems are usually equipped with either a high-side liquid receiver or a low-side accumulator in order to absorb fluctuations in refrigerant charge. III EXPERIMENTAL SET-UP In this project we have concentrated our study on the domestic air conditioner ie. subcooled VCRS by employing heat exchanger and Simple VCRS. The performance of the subcooled system is elevated by installing heat exchanger between suction and discharge line. In case of simple VCRS system air cooled condenser has been used .The experimental setup (figure 1 and figure 2) consists of a single stage vapour compression system with the basic components i.e. evaporator, compressor, expansion device , condensers and a coil heat exchanger. The coil type heat exchanger has been attached in series after condenser and parallel to the suction line before compressor. The shifting of air cooled air conditioning system to the subcooled i.e.(system with heat exchanger) air conditioning system is done with the help of the system of hand set valve attached. The whole experiment is carried out on R134a (tetra flouroethane) which is used as refrigerant in setup. After taking the reading with subcooled system i.e.(system with heat exchanger) ,we perform the same experiment with air cooled condenser VCRS .Ammeter and voltmeter are used to measure the electrical current and voltage of input power respectively. The bourdon pressure gauges are used to measure the suction (inlet) and discharge (outlet) pressure of compressor. Temperatures of refrigerant and the ambient air at different points are measured by use of RTD PT100 type thermocouples. Before temperature measurement, the surface of the tubes are polished for removing any type of dust or rust 168 ELK Asia Pacific Journals – Special Issue and then the thermocouples are laid own onto the surface. Insulation tapes are wrapped around the copper tubes to prevent any heat losses to ambient air. Proc. Of the Int. Conf: ARIMPIE-2015 conditions. Data are recorded after a steady state condition is achieved in the system and the properties of refrigerant (R134a) and air remained constant (after 15 min). Experimental tests are performed at three ambient temperatures i.e. 29°C, 33°C and 39°C in order to have better understanding of the system behaviour under different climatic conditions. Table 1: Result obtained at 29°C ambient temperature Parameter Symbo l Unit Ambient air Temperature at DBT-29°C , WBT - 21°C , RH - 50% Subcooled VCRS Figure 1: Experimental set-up with subcooled VCRS with heat exchanger and air cooled condenser Figure:2 Experimental set-up of coil heat exchanger IV EXPERIMENTAL RESULTS AND DISCUSSIONS In order to estimate the effect of subcooled VCRS system i.e.(system with heat exchanger) and air cooled conditioning system i.e.(simple VCRS) and also comparing the results of both subcooled VCRS system and air cooled condenser, experimental tests are performed in two subsequent stages. In the first stage of the experiment, air-cooled condenser is used. After getting the data, in the second stage subcooled VCRS system is used under the same ambient Air Cooled Condenser Evaporator Absolute pressure Peva Condenser Absolute pressure pcon bar 10.75 18.49 Evaporator exit temperature T1 °C -15 15 Compressor exit temperature T2 °C 25 71 Condenser exit temperature T3 °C 19 52 Evaporator inlet temperatur e T4 5 8 1.4 2.12 225 225 Total electric current Total electric voltage 3.98 bar 2.91 I Amp V Volt 169 ELK Asia Pacific Journals – Special Issue Parameter Symbol Unit Ambient air Temperature at DBT-33°C , WBT - 26°C , RH - 57% Subcooled VCRS Evaporator Absolute pressure Peva bar Condenser Absolute pressure pcon T1 °C T2 °C Compressor exit temperature 21.42 -7 18 35 T3 I 75 Volt Evaporator Absolute pressure Peva Condenser Absolute pressure pcon Evaporator exit temperature T1 Compressor exit temperature T2 Condenser exit temperature T3 Total electric current 225 Air Cooled Condenser bar 4.33 5.52 bar 12.44 26 -2 20 55 81 51 71 11 15 2 2.31 225 225 °C °C °C °C T4 2.24 Total electric voltage V Subcooled VCRS Evaporator inlet temperature 1.87 Unit 13 °C Amp Sym bol Ambient air Temperature at DBT-39°C , WBT - 32°C , RH 61% 62 °C 5 T4 5.1 10.97 40 Evaporator inlet temperature Total electric current 3.41 Parameter Air Cooled Condenser bar Evaporator exit temperature Condenser exit temperature Proc. Of the Int. Conf: ARIMPIE-2015 225 Table 2: Result obtained at 33°C ambient temperature Total electric voltage I Amp V Volt Table 3: Result obtained at 39°C ambient temperature 170 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 d. COP = Qr Wc where, h1 = enthalpy of refrigerant at inlet of compressor in kj/kg h2 = enthalpy of refrigerant at exit of compressor in kj/kg h3 = enthalpy of refrigerant at exit of the condenser in kj/kg h4 = enthalpy of refrigerant at entry of evaporator in kj/kg. Figure 3: Pressure-enthalpy (P-h) diagram for subcooled VCRS and air cooled air conditioning system at 29 °C ambient air temperature. The voltage meter and ampere meter attached in the experimental set-up . Using this voltage and ampere reading, work done of the compressor is obtained Table 4, 5 and 6 shows the results obtained from the observations recorded at three different ambient air temperature i.e. 29°C, 33°C and 39°C. TABLE 4: RESULTS OF THE EXPERIMENT AT AMBIENT AIR TEMPERATURE OF 29 °C V CALCULATION AND RESULTS Based on the experimental results, thermodynamic properties of the refrigerant at different points in the cycle are obtained using the P-H chart of refrigerant R-134a and the parameters such as mass flow rate, cooling capacity and COP of the system are calculated from the equations: In case of subcooled VCRS total compressor work reduces about 34%. There is an increase of 26% in the COP of subcooled VCRS as compare to aircooled VCRS Performance Results of Air Conditioner (Tamb - 29oC) a. Compressor Work Wc = V * I = mref* (h2 –h1) b. Mass flow rate of refrigerant mref = Wc (h2 –h1) c. Cooling effect produced Qr=mref* (h1 –h4) Parameter Compressor Work , Wc Unit Wat t Variation( %) Air Cooled Subcooled VCRS VCRS 447 315 - 34% 3 3.9 26% Coefficient of performance COP TABLE 5: RESULTS OF THE EXPERIMENT AT AMBIENT AIR TEMPERATURE OF 33°C 171 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 At 33°C ambient air temperature, Subcooled Performance Results of Air Conditioner (Tamb 33oC) Parameter Air Uni Cooled Subcoole Variation( t VCRS d VCRS %) Compressor Work , Wc Wat 504 t 420.75 -18% Coefficient of performance 2.62 2.8 6% COP VCRS total shows a reduction of 18% in compressor work. There is an increase of 6% in the COP of Subcooled VCRS as compare to air cooled condenser which is less by 32% than at 29°C. Performance Results of Air Conditioner (Tamb 39oC) Parameter Air Uni Coole t d Subcoole VCRS d VCRS Variati on(%) Compressor Work , Wc Wa 519.75 tt 450 -14% 2.5 3% Effect of ambient temperature on Compressor work Figure 4 shows the variation of compressor work for subcooled and air cooled VCRS in terms of ambient air temperature. As seen from the graph, with increase in air temperature compressor work is increased and there is considerable difference between performance of two systems . The compressor work for the subcooled VCRS is significantly low as compare to air cooled VCRS. In air cooled system, condenser rejects heat to the external fluid i.e. air, while in subcooled system the high pressure refrigerant is subcooled at the expense of superheating the vapour entering the compressor. Therefore the saturation pressure is decreased in case of subcooled VCRS which in turn lowers the compressor power for same cooling capacity. Also with the increase in ambient air temperature the heat rejection rate from the condenser decreases which puts an excessive load on to the compressor. Coefficient of performance 2.43 COP TABLE 6: RESULTS OF THE EXPERIMENT AT AMBIENT AIR TEMPERATURE OF 39 oC At 39°C ambient air temperature, Subcooled VCRS total shows a reduction of 14% in compressor work.There is an increase of 3% in the COP of Subcooled VCRS as compare to air cooled condenser. Figure 4: compressor work variation at different ambient air temperature 172 ELK Asia Pacific Journals – Special Issue EFFECT OF AMBIENT TEMPERATURE ON COP Proc. Of the Int. Conf: ARIMPIE-2015 whereas in case of air cooled VCRS the increase in Compressor work and COP decrease by 26%. The experimental investigation also verifies that condensing temperature and pressure decreases in case of subcooled VCRS system which decreases the compressor work. The subcooled VCRS system thus results in increasing cooling load and decreasing power consumption of the compressor which consequently save enough amount of energy .Thus the use of subcooled system with heat exchanger will reduce the peak load conditions of power network in extreme hot weather conditions because vapour compression air conditioners are the main cause of peak loads. Figure 5 shows the variation of COP with ambient air temperature for subcooled VCRS and air cooled VCRS. As the experimental results show that there is decrease in COP with the increase in ambient air temperature. Also the COP of subcooled VCRS is more then the air cooled VCRS because of high cooling effect and low compressor work. The difference between two curves is very large at 29°C and it decreases as ambient air temperature increases. This decrease in COP is due to the reduction in cooling load with increase in ambient air temperature. _______________________________________________ REFERENCE [1] C.E. Groseclose, “Cost comparison of air conditioning refrigerant condensing systems.” Refrigeration Engineering, June (1954) 54–58. [2] Gosney, W.B., "Principles of Refrigeration", Cambridge University Press, Cambridge, U.K.,1982. [3] R.L. Webb, “A unified theoretical treatment for thermal analysis of cooling towers, evaporative condensers, and fluid coolers” ASHRAE Trans 90 (Part 2B) (1984) 398–415. FIGURE 5: Cop variation at different ambient air temperature VI CONCLUSION In this experiment a subcooled VCRS with heat exchanger and air simple air cooled VCRS is experimentally investigated. Experimental results show that there is considerable increase in the COP of the subcooled VCRS as compare to air cooled VCRS and further there is significant decrease in compressor work for subcooled vcrs system as compared air cooled vcrs. In case of subcooled VCRS there is an increase in the steady state COP from 3 to 3.9 under the following conditions: the wet-bulb temperature is 21°C, drybulb temperature is 29°C, air velocity is 2.4 m/s and power consumption is decreased by 34% [4] McLinden, M.O., "Optimum Refrigerants for Non-Ideal Cycles: An Analysis. Employing Corresponding States•, Proceedings of ASHRAE-Purdue CFC & IIR-Purdue Refrigeration Conferences, pp. 69-79, W. Lafayette, IN, July 1990. [5] Domanski, P.A., Didion, D.A., 1994. Evaluation of suction-line/liquid-line heat exchange in the refrigeration cycle, International Journal of Refrigeration 17, 487-493. [6] Linton, J.W., Snelson, W.K., Hearty, P. F., 1992. Effect of condenser liquid subcooling on system performance for refrigerants CFC-12, HFC-134a and HFC-152a. ASHRAE Transactions 98, 160-146 [7] Arora C.P., (2001), “Refrigeration and Air conditioning”, book. 173 ELK Asia Pacific Journals – Special Issue 29. COMPARISON OF DIFFERENT FAILURE THEORIES OF COMPOSITE MATERIAL: A REVIEW Supriya Kabra Department of Mechanical Engineering Maulana Azad National Institute of Technology Bhopal, India
[email protected], N.D.Mittal Department of Mechanical Engineering Maulana Azad National Institute of Technology Bhopal, India
[email protected] Abstract— Different failure theories are used to assess failure analysis of composite materials as Failure criteria is important step of failure analysis. As composites material are orthotropic or anisotropic by nature so shows complex failure .There are many modes of failure such as basically fibre failure, matrix failure, inter fibre failure crack propagation, delaminations. In this we compare five theory such as Tsai , Puck, Rotem, Zinoviev and Edge there failure mode and approach used.In this we reviewed paper of WWFE by Hinton in 2002 for comparing the theories. This paper aims to solve basic problem associated with use of failure criterion for composite material. Keywords—Fibre Reinforced composites (FRC); Failure Theories; Modes of Failure; Fibre Failure; Matrix Failure I. INTRODUCTION Fibre reinforced polymer composites are an extremely broad and versatile class of material. There high strength coupled with lightweight leads to there use wherever structural efficiency is at a premium. Applications can be found in Proc. Of the Int. Conf: ARIMPIE-2015 aircraft, process plants, sporting goods and military equipment[8]. In recent scenario, fibre-reinforced polymer (FRP) composites are finding increasing application in aerospace, marine and many other industries due to the advantages they provide performance, structural efficiency and cost. The main reasons for composite material is mechanical properties of composites such as high strength/stiffness to weight ratio, excellent corrosion resistance and low co-efficient of thermal expansion.There structural properties according to requirements which add versatility for sensitive applications[13]. The process of damage development and failure in composite materials is very complicated. The effective properties of the composite usually depend on the average stresses or strains in the phases. However, an analytical micromechanical damage analysis should properly take into account the detailed microstructure, the spatial deformation fields, existing defects, criteria for microfailure and its evolution, and the way different defects and modes of failure interact as loading progresses [1]. This paper draws together the results from the “ World-Wide Failure Exercise” (WWFE), coordinated by Hinton et.al. in which the predictions were provided by the originators of the theories . These included fibre type (carbon, glass), matrix type (various epoxies), lay-up configuration (unidirectional, multidirectional) and a variety of load states (uniaxial, biaxial) [2]. II. FIBRE REINFORCED COMPOSITES The carbon fibre reinforced polymer matrix composites has been used more and more progressively in various fields including the airplane, fuel cell vehicle, electricity generation and communication power systems due to their advance benefit such as high strength/stiffnessto-weight ratio, excellent resistance to fatigue and corrosion as well as acceptable durability[8]. The metal currently being used is either aluminium, magnesium or titanium, and the fibre-reinforced layer is either glass-reinforced, carbon reinforced or kevlar- reinforced 174 ELK Asia Pacific Journals – Special Issue composite[10]. The carbon fibre composites are used to manufacture the laminated composites which utilizes the carbon fibres having same orientation in each layer, and these layers are packed in angled orientations to get high stiffness and strength in different directions. [8]. Fibre reinforced polymers have gathered remarkable market as material is used in a wide variety of structural applications around the world. But have low impact resistance due to which mechanical properties are affected [9].The light weight of the composites brings down the fuel consumption considerably therefore increase the overall engine efficiency. So composite materials have gain popularity in roads in aero and auto industries. Proc. Of the Int. Conf: ARIMPIE-2015 failure 3 Puck Fibre failure in compressive, Fibre failure in compressive, Interfibre failure Mode A (for transverse tension), Inter-fibre failure Mode B (for moderate transverse compression), Interfibre failure Mode C (for large transverse [11] compression), 4 Rotem[1 1] III. MODES OF FAILURE OF COMPOSITE LAMINATE Modes of failure of composite laminate are basically fibre failure (shear, tensile, compressive) , matrix failure (transverse tension, transverse compression, shear), delamination ,etc. Different theories of failure have different modes of failure and different mechanism involved which represented different approaches for failure analysis[2]. 5 Edge[11] Table 1 Different Failure theories there failure mode and approach. [11] S. N o Failure 1 Tsai [11] 2 Failure mode Approach represented Fibre tension/ compression and matrix tension and compression and shear Interactive progressive quadratic failure criterion Longitudinal tension failure, Longitudinal compressive failure, Transverse compressive failure, In-plane shear Developme nt of Maximum stress theory Physically based 3-D phenomeno logical models Longitudinal tension failure, Longitudinal compressive failure, Matrix failure. Interactive matrix and fibre failure theory Longitudinal tension failure, Longitudinal compressive failure, Transverse tensile failure, Transverse compressive failure, In-plane shear failure, Combined transverse tension and shear, Combined longitudinal compression and shear, Delamination British Aerospace, In-house design method Theory Zinovie v [11] IV. DIFFERENT FAILURE THEORIES a. Tsai failure theory: From W.Tsai et.al. (1998) Failure criteria of composite laminate was based on progressive quadratic failure criterion, it has been noted that the theory predicts enhancement of strength under compression-compression biaxial loading[1]. In WWFE Tsai theory work on different composite material with different layups and 175 ELK Asia Pacific Journals – Special Issue different loading condition and there after the stress-strain curve was plot. A ply in a laminate may fail by micro-cracking when the transverse strain on the ply axis is positive (tensile). If micro-cracking takes place in a ply, we assume that it happens instantaneously within a limited region of high stress in a ply. Having other plies at the same point in a laminate, the laminate as a whole may be capable of continuing to carry the prevailing load[3]. According to WWFE conducted by Hinton et. al. (1998) the comparison of different theories with different test resulted to some positive and negative points about this theory [2]. This theory broadly fits shape of the experimental data. Predictions are very conservative (i.e. safe) for both quadrants. Negative effect of the theory is as overall the predictions are approx 50% too conservative suggesting that there is some weakness in the theory or its application. b. Zinoviev Theory: Peter A.Zinoviev et.al. (1998) considered the deformation and failure processes of multilayered hybrid composites in a state of plane stress which can be considered as a structural phenomenological one, is a coupled deformation failure model (DFM).[4] Hinton et. al. (1998) The Zinoviev failure theory was based on he maximum stress failure theory, which embodies a very simple, but carefully structured, set of non-interactive criteria to identify failure mechanisms and to take appropriate post-initial failure action [2]. In WWFE Hinton et.al. gave reasonably good descriptions of the unidirectional lamina failure envelopes though, as expected for a noninteractive failure theory. This theory was one of the best at predicting initial as well final failure events for multi-directional laminates. The theory assumed linear-elastic material properties, it also gave reasonably good descriptions of nearly all of the stress/strain curves and only failed to predict the observed large deformations[2]. Proc. Of the Int. Conf: ARIMPIE-2015 c. Puck’s Theory: In 2002 Puck et.al. failure of different laminates because of non-linearity is due to microdamage, matrix cracking, and changes in fibre angle with increasing strains. Puck performed experimental study of laminate to Pre-IFF non-linear stress/strain analysis and residual stress analysis. [5] The strength of a reasonably well designed laminate depends to a very high degree on the load carrying capacity of its fibres, because normally most of the load is concentrated in the fibres. Therefore, the FF-criteria have the highest importance for the design of laminates. Puck used the new IFF criteria are based on a ‘‘modified Mohr hypothesis” which has been adapted to transversally isotropic material.[5] The results show that the Puck theory captures most features of the experimental results appears to be one of the best available currently.[2] According to Hinton et.al. there are weakness in Puck’s theory like The theory has a unique open envelope Which needs to be reconciled with experimental evidence, no leakage prediction, theory was unable to predict large deformation, Un-conservative strength prediction, not capturing strain deviations and the initial and intermediate failure strengths are some 50% lower than those recorded in experiments[2]. d. Rotem Theory: Rotem in 2002 gives the criterion that distinguishes fibre failure and matrix failure. Only in-plane loads are considered, neglecting the possibility of inter- laminar failure. This criterion separates the failure to fibre and matrix failure [6] The criterion assumptions: is based on three basic 1. The failure of a FRC material laminate will occur either in the fibres or in the matrix. The onset of the failure is a localized phenomenon. 2. The laminate has no free edges, i.e. the laminate is wide enough and clamped on its outer contour and 176 ELK Asia Pacific Journals – Special Issue has no holes. Therefore only in-plane stresses are effective. There are no interlaminar stresses which Proc. Of the Int. Conf: ARIMPIE-2015 lower final failure strength values than the other theories [12] may cause failure. Acknowledgment 3. The matrix material is weaker and softer than the fibres.[6] Hinton et. al. the stress/strain curves by this criteria were truncated at much lower strains than the final strains observed. As post failure analysis prediction does not fit the experimental data in shape or magnitude and very conservative in two quadrants are the fundamental weakness of this theory .[2] e. Edge theory: E.C. Edge postulated that In-plane shear failure is regarded as a final failure and transverse tension failure has been regarded as initial failure. Final failure means that the laminate is either considered incapable of taking further load or a fibre failure has occurred. The stressbased Grant Sanders method employed for failure analysis of laminate for predicting initial and final failure [7] and consider the effects of matrix degradation on the stress/strain curves [2]. Hinton et.al. postulated fundamental weakness of this theory are Slightly un-conservative under tension–compression and doubt about compression–compression quadrant very low initial strength prediction. The theory does not fit the experimental curves at large strains. Fundamental problem in post failure analysis[2]. V. CONCLUSION: From all the above theory we can see the result for ranking the accordingly as the theories have some fundamental weaknesses. According to Hinton et. al. Zinoviev is the best theory for composite material which consider both post and pre failure of laminate and gave descriptions of nearly all of the stress/strain curves[2] and has minimum weakness and type of post failure modeling utilized by Rotem produced much The research have been supported by Maulana Azad National Institute of Technology, Bhopal for providing proper environment and resource for successfull completion of this research so is gratefully acknowledged. References [1] Hakan Kilic, Rami Haj-Ali “Progressive damage and nonlinear analysis of pultruded composite structures”, Composites: Part B 34 2003; 235–250. [2] M.J. Hinton, A.S. Kaddour, P.D. Soden, “A comparison of the predictive capabilities of current failure theories for composite laminates, judged against experimental evidence”, Compos Sci Technol 2002; 62 :1725–1797. [3]. Liu K-S, Tsai SW. “A progressive quadratic failure criterion of a laminate”, Compos Sci Tech 1998;58:1023–32. [4] Zinoviev P, Grigoriev SV, Labedeva OV, Tairova LR. “Strength of multilayered composites under plane stress state”, Compos Sci Technol 1998;58:1209–24. [5] Puck A, Schu¨ rmann A. “Failure analysis of FRPlaminates by means of physically based phenomenological models—part “, Compos Sci Technol 2002;62:1633–62 [6] Rotem A. “The rotem failure criterion theory and practice”, Compos Sci Technol 2002;62:1663–71 [7] Edge EC, Theory V. “Experiment comparison for stress based Grant-Sanders method”, Compos Sci Technol 2002;62:1571– 89. 177 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 [8]. Liu P.F(2010), Zheng J.Y. “Recent developments on damage modeling and finite element analysis for composite laminates: A review”, Materials and Design 2010; 31: 3825–3834. [9]. M.H. Malik, A.F.M. Arif , F.A. AlSulaiman, Z. Khan. “Impact resistance of composite laminate flat plates – A parametric sensitivity analysis approach”, 2013; 102 : 138– 147. [10]. F.D. Morinière, R.C. Alderliesten, R. Benedictus . “Modelling of impact damage and dynamics in fibre-metal laminates A review”, 2014 ;67:27e38. [11] P. D. Soden, M. J. Hinton , A. S. Kaddour. “A Comparison of the Predictive Capabilities of Current Failure Theories for Composite Laminates”. Compos Sci Technol 1998; 58:1225-1254. [12] A.S. Kaddour, M.J. Hinton, P.D. Soden. “A comparison of the predictive capabilities of current failure theories for composite laminates: additional contributions”. Compos Sci Technol 2004; 64 : 449–476 [13] Panda S.K.(2011), Singh B.N. Large amplitude free vibration analysis of thermally post-buckled composite doubly curved panel using nonlinear FEM . Finite Elements in Analysis and Design 2011; 47:378–386. 178 ELK Asia Pacific Journals – Special Issue 30. USE OF POLYMER MATRIX COMPOSITES FOR CONVENTIONAL STEEL DRIVE SHAFTS: A STUDY Yusuf Abdulfatah Abdu1*, Tijjani M Shfi’i1*, Salisu Umar Musa1, Umar Shasu1, Hamza Alhassan1, Prof. U.K. Gupta1 1 Dept. of Mechanical & Automobile Engineering, Sharda University,Greater Noida, India *
[email protected] *
[email protected] Abstract: - The present study throws light on the idea of replacement of conventional steel material with composite material for drive shaft. There are several advantages of design due to its high specific stiffness and strength. Automotive drive shaft is usually manufactured in two pieces in order to increase the fundamental bending natural frequency because it is inversely proportional to the square of beam length and proportional to the square root of specific modulus. This composite can be made as singlepiece shafts, in other to reduce the overall weight. Carbon/Epoxy and Kevlar/Epoxy composites were designed and analyzed for their appropriateness in terms of torsional strength, bending natural frequency and torsional buckling by comparing them with the conventional steel drive shaft with the same design constraints and the best-suited composite was recommended. The achievement of weight reduction with adequate improvement of mechanical properties has made composite a very good replacement material for conventional steel without increase in cost or decrease in vehicle quality and reliability. Keywords—Composite Material, Drive Shaft, Carbon/Epoxy, Kevlar/Epoxy, Torsional strength, Bending natural frequency, Torsional buckling I. INTRODUCTION An automotive driveshaft is a rotating shaft that transmits power from the engine to the differential gear of rear wheel drive vehicles. Proc. Of the Int. Conf: ARIMPIE-2015 Composites have high specific modulus, strength and less weight. The fundamental natural frequency of carbon fiber drive shaft can be twice as that of the steel or aluminum, because the carbon fiber composite material has more than four times the specific stiffness, which makes it possible to manufacture the drive shaft of passenger cars in one piece. A one piece composite shaft can be manufactured so as to satisfy the vibration requirements. This eliminates all the assembly, connecting the two piece steel shaft and thus minimizes the overall weight, vibrations and cost. Due to weight reduction, fuel consumption will be reduced. They have high damping capacity and hence they produce less vibrations and noise. They have good corrosion resistance, greater torque capacity, longer fatigue life than steel and aluminum [1]. A typical composite material is a system of materials composing of two or more materials (mixed and bonded) on a macroscopic scale. Composite drive shafts have solved many automotive and industrial problems accompany the usage of the conventional metal ones because the performance is limited due to lower critical speed, weight, fatigue and vibration. Numerous solutions such as flywheels, harmonic dampers, vibration shock absorbers and multiple shafts with bearings, couplings, and heavy associated hardware have shown limited success in overcoming the problems. Advanced composites utilize a combination of resins and fibers, customarily carbon/graphite, Kevlar, or fiberglass with an epoxy resin. The fibers provide higher stiffness, while the surrounding polymer resin matrix holds the structure together [2]. Carbon-fiber composites are an alternative to glass-fiber composites because they are stiffer and therefore have better potential for structural applications. They can also be made lighter than their glass-reinforced counterparts, providing a significantly higher weight-savings potential. Generally composite materials have very high specific strength and specific modulus. This translates into reduced material and energy costs. Though the material cost is 10-15 times that of steel, manufacturing 179 ELK Asia Pacific Journals – Special Issue techniques such as SMC (Sheet Moulding Compound) and SRIM (Structural Reaction Injection Moulding) are substantially lowering the cost and production time in manufacturing automobile parts [3]. A. Basic Concepts of Composite Materials Composite materials are basically hybrid materials formed of multiple materials in order to utilize their individual structural advantages in a single structural material. The constituents are combined at a macroscopic level and are not soluble in each other. Composite materials have been used in aircraft and space vehicles as they have high specific strength (Strength/Density), high specific stiffness (Stiffness/Density) and very good fatigue properties. With the composite material the designer can vary structural parameters, such as geometry and at the same time vary the material properties by changing the fiber orientation, fiber content. Classification of Composite Materials i. Polymer matrix composites ii. Metal matrix Composites iii. Ceramic Matrix B. Advantages of Composites over Conventional Materials i. ii. High strength to weight ratio. High stiffness to weight ratio. iii. iv. High impact resistance. Better fatigue resistance. v. vi. Improved corrosion resistance. Good thermal conductivity. vii. High damping capacity. Proc. Of the Int. Conf: ARIMPIE-2015 i. ii. iii. iv. v. II. DRIVE SHAFT A drive shaft, propeller shaft or prop shaft is a mechanical component for transmitting torque and rotation, usually used to connect other components of a drive train that cannot be connected directly because of distance or the need to allow for relative movement between them. A. Functions of the Drive Shaft i. ii. iii. viii. Low coefficient of thermal expansion C. Applications of Composite Materials The common applications of composites are extending day by day. Nowadays they are used in medical applications too. Some other fields of applications are, Automotive : Drive shafts, clutch plates, fibre Glass/Epoxy leaf springs for heavy trucks and trailers, rocker arm covers, suspension arms and bearings for steering system, bumpers, body panels and doors. Aerospace: Drive shafts, rudders, elevators, bearings, landing gear doors, panels and floorings of airplanes, payload bay doors, remote manipulator arm, high gain antenna, antenna ribs and struts etc. Marine: Propeller vanes, fans & blowers, gear cases, valves & strainers, condenser shells. Chemical Industries: Composite vessels for liquid natural gas for alternative fuel vehicle, racked bottles for fire service, mountain climbing, underground storage tanks, ducts and stacks etc. Electrical & Electronics: Structures for overhead transmission lines for railways, Power line insulators, Lighting poles, Fibre optics tensile members etc. iv. It must transmit torque from the transmission to the differential gear box. The drive shaft must also be capable of rotating at very fast speed required by the vehicle. The length of the drive shaft must also be capable of changing while transmitting torque. Length changes are caused by axle movement due to torque reaction, road deflection, braking load, and so on. The drives shaft must also operate through constantly changing the angles 180 ELK Asia Pacific Journals – Special Issue v. vi. Proc. Of the Int. Conf: ARIMPIE-2015 between the transmissions the differential and the axels. A slip joint is used to composite for this motion. The slip joint is made of an internal and external spline. The dive shaft should provide a smooth flow of power to the axles. Fig 2.1 Schematic Diagram of the two Piece Drive Shaft for a Rear Wheel Driving System [4] This construction increases the weight of the assembly due to the additional centre support bearings and other mountings. Together these parts need to be maintained and serviced regularly which adds for the maintenance cost. The problem can however be solved by replacing the conventional two piece steel drive shaft with single composite drive shaft which can full-fill the functionality of an automotive drive shaft without any weight penalty, but for a composite driveshaft the prominent failure mode is shear buckling rather than material failure, which needs to be analyzed. DRIVE SHAFT The fundamental natural bending frequency for passenger cars, small trucks and vans of the propeller shaft should be higher than 6,500 rpm to avoid whirling vibration and the torque transmission capacity of the drive shaft should be larger than 3,500 Nm [5]. The conventional steel shaft was designed to facilitate comparison in terms of mass savings. But the conventional driveshaft or the composite one, the design should be based on the following criteria: i. Torsional strength ii. Torsional buckling and iii. Bending natural frequency. The SM45C steel was selected, since it is widely being used for the design of conventional steel shaft. Table 4.1 Properties of SM45C steel Properties Steel of Value Unit Symbol Young’s Modulus E 207 GPa Shear Modulus G 80 GPa Poisson’s Ratio 𝟅 0.3 --- Density Ρ 7600 kg/m2 Shear Strength Ss 370 MPa III. DESIGN SPECIFICATIONS The following specifications were assumed suitably, based on the literature and available standards of automobile drive shafts: Table 3.1: Design requirements and specifications [3] Parameter Shaft of Value Unit Symbol Torque Transmitted T 3500 N-m Outer Diameter Inner Diameter do di 120 112.74 Length of Shaft L 1800 mm mm mm IV. DESIGN OF CONVENTIONAL STEEL A. Torsional Strength Since the shear stress is small near the middle, then if there is no other stress considerations other than torsion, a hollow shaft may be used to reduce the weight. The torque transmission capacity of a steel shaft; the shear strength (Ss) at the outer diameter (do) of the shaft is given by (1) Where, 181 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 T is maximum torque applied in N-m = 816.875 N/mm2 Ss is the shear strength in MPa = 63.117 d0 and di are outer and inner diameters of the shaft in mm. 106 N-mm Therefore, Hence, The wall thickness of the hollow steel shaft: t= r0- r1 (2) t =3.63 mm C. Bending Natural Frequency Natural frequency can be found using the following two theories: A shaft is considered as a long shaft, if [6]; i. Timoshenko Beam Theory ii. Bernoulli Euler Theory According to Bernoulli-Euler beam theory, by neglecting shear deformation and rotational inertia effects, the bending natural frequency of a rotating shaft is given by [3]; (3) (7) Where, Where, m′ is mass per unit length in kg/m Ix is area moment of inertia in x-direction (longitudinal) in m4. T = 13.868 6 10 N-mm B. Torsional buckling r is the mean radius, such that; (4) (8) =58.184 mm (9) Substituting, Substituting, For a long shaft, the torsional buckling capacity: Thus the designed SMC45 steel driveshaft meets all the requirements. The total mass of the shaft is: m = m′L (10) (5) m = 18.157 kg Where, Critical stress V. DESIGN OF COMPOSITE DRIVE SHAFT ) is given by; A. Why Carbon Epoxy Composite? Following are the features of carbon epoxy composite, the reason for which it is chosen. (6) i. Carbon epoxy composite gives high tensile strength, high modulus of rigidity as compared to other composites. Substituting, 182 ELK Asia Pacific Journals – Special Issue ii. Proc. Of the Int. Conf: ARIMPIE-2015 Carbon epoxy composite has unique damping characteristic. Carbon epoxy composite has positive coefficient of thermal expansion i.e. tensile strength of this composite increases with temperature. Carbon epoxy composite is fatigue, wear and corrosion resistant. iii. iv. Table 5.1 Mechanical properties of Carbon Fiber Composite [7]. Mechanic al Properties shaft. C. Bending natural frequency (12) From the Table 5.1, the density of Carbon/Epoxy The mass of Carbon/Epoxy composite driveshaft is, (13) Units Carbon/Epo xy Kevlar/Epo xy E11 GPa 175 75 E22 GPa 8 6 G12 GPa 5 2 𝟅 --- 0.3 0.34 1600 1400 850 280 40 30 ρ Kg/m 3 St1=Sc1 MPa St2=Sc2 S12 MPa 60 60 MPa B. Design of Carbon/Epoxy Driveshaft 60% fibre volume fraction Carbon/Epoxy shaft (Vf = 60%) with standard ply thickness of 0.13 mm was selected. Considering the hollow composite shaft as an isotropic cylindrical shell, the buckling torque is given by: (11) Where, m = 3.82 kg VI. DESIGN ANALYSIS Finite Element Analysis (FEA) is a computer-based numerical technique for calculating the strength and behavior of engineering structures. It can be used to calculate deflection, stress, vibration, buckling behavior and many other phenomena. It also can be used to analyse either small or large scale deflection under loading or applied displacement. In this review the FEA is carried out by using the ANSYS. Firstly, we don’t know the displacement and other quantities like strains, stresses which are then calculated from nodal displacement. a. Static Analysis A static analysis calculates the effects of steady loading conditions on a structure, while ignoring inertia and damping effects, such as those carried by time varying loads. A static analysis is used to determine the displacements, stresses, strains and forces in structures or components caused by loads that do not induce significant inertia and damping effects. A static analysis can however include steady inertia loads such as gravity, spinning and time varying loads. If these values exceeds above the allowable values then component is going to fail. Hence static analysis is necessary. Ex and Ey are the Young’s moduli in ‘x’ and ‘y’ directions respectively. r and t are the mean radius and thickness of composite 183 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 together with capabilities. improved torque carrying VII. RESULTS AND DISCUSSION Fig 6.1 Deformation of Composite drive shaft b. Modal analysis The modal analysis is one of the important analyses for drive shaft as we are eliminating two piece drive shafts with single piece. The modal analysis is required as the first mode frequency of vibration must be less than shaft operating frequency to avoid failure of drive shaft. Fig. 6.2 Boundary Condition for the model analysis c. Buckling analysis Buckling analysis is a technique used to determine buckling loads (critical loads) at which a structure becomes unstable, and buckled mode shapes. For thin walled shafts, the failure mode under an applied torque is torsional buckling rather than material failure. For a realistic driveshaft system, improved lateral stability characteristics must be achieved From the analysis, the key results of wall thickness, torsional buckling capacity, bending natural frequency, and total mass for SM45C steel (as applicable) and Carbon/Epoxy drive shafts were extracted and summarized in a table 7.1 below. Table 7.1 Comparison of SM45C Steel, Carbon/Epoxy and Kevlar/Epoxy drive shaft Material t Tb (N- fnb m (mm m) (Hz) (kg) ) SM45C 63117.3 104.14 18.15 Steel 3.63 5 8 7 101.90 3.82 Carbon/Epo 1.82 2272.49 3 xy 241861 101.90 7.42 Kevlar/Epox 5.72 3 y Table 7.1 reveals that use of Carbon/Epoxy results in a mass saving of 87.01% and Kevlar/Epoxy were equal to 74.76% when compared to the conventional SM45C steel driveshaft. Moreover, the torsional buckling capacity and bending natural frequency are adequate enough to meet the design requirements in the case of Carbon/Epoxy driveshaft. Conclusion Based on the specifications a comparison of conventional drive shaft with composite drive shaft based on design and analysis has been done. The study reveals that use of Carbon/Epoxy result in a weight saving of 87.01% when compared to conventional steel, whereas a Kevlar/Epoxy result is 74.76%. Though the mass saving is substantial in both the polymer matrix composites considered, making either of the composites a better choice for the conventional high quality SM45C steel. These specifications are adequate enough to meet the design requirements in the case of Carbon/Epoxy. 184 ELK Asia Pacific Journals – Special Issue Acknowledgement I express my deep sense of gratitude and indebtedness to my external guide Prof. (Dr.) Vikas Dhawan, Department of Mechanical Engineering, ITS Engineering College, for providing precious guidance and inspiring discussion throughout the course of this paper. I am very much thankful to Prof. U.K Gupta for giving guidance to my project work in Sharda University, Greater Noida. References [1] Deepti kushwaha, Gaurav Saxena, “Optimal Design and Analysis of Composite Drive Shaft for a Light Commercial Vehicle” International Journal of Advance Engineering and Research Development, ISSN (Print): 2348-6406 ISSN (Online): 2348-4470. [2] Parshuram D and Sunil Mangsetty, “Design and Analysis of Composite/Hybrid Drive shaft for Automotives” International Journal of Engineering and science, 2(01) (2013) pp. 160171. [3] R. Srinivasa Moorthy, Yonas Mitiku and K. Sridhar, “Design of Automobile Driveshaft using Carbon/Epoxy and Kevlar/Epoxy Composites”, American Journal of Engineering Research (AJER) e-ISSN : 2320-0847 pISSN:2320-0936 Volume-02, Issue-10, pp-173179. [4] Madhu K. S, Darshan B.H and Manjunath K, “Buckling Analysis of Composite Drive Shaft for Automotive Application”, Journal of Innovative Research and Solution, 1A (02) (2013) pp63-70. [5] Sagar R Dharmadhikari, Sachin G Mahakalkar, Jayant P Giri,& Nilesh D Khutafale, “Design and Analysis of composite Drive shaft using ANSYS and Genetic algorithm” A Critical Review, International Journal of Modern Engineering Research, 3 (1) (2013) pp. 490-496. [6] Gummadi Sanjay & Co., Optimum Design and Analysis of a Composite Driveshaft for an Automobile, Department of Mechanical Engineering, Blekinge Institute of Technology, Proc. Of the Int. Conf: ARIMPIE-2015 Karlskrona, Sweden, 2007, ISRN: BTH AMTEX--2007/D-09--SE. [7] www.acpsales.com/upload/MechanicalProperties-of-Carbon-Fiber-CompositeMaterials.pdf [8] M.A.K. Chowdhuri, R.A. Hossain, Design Analysis of an Automotive Composite DriveShaft, International Journal of Engineering and Technology Vol.2 (2), 2010, 45-48. [9] V. S. BhajantrI, S. C. Bajantri, and A. M. Shindolkar, S. S. Amarapure “Design and Analysis of Composite Drive Shaft” Ijret: International Journal of Research in Engineering and Technology, eISSN: 2319-1163 | pISSN: 2321-7308. [10] D. Dinesh and F. Anand Raju, ”Optimum Design and Analysis of A Composite Drive Shaft For An Automobile By Using Genetic Algorithm And Ansys”, International Journal of Engineering Research and Applications, 2 (04) (2012) pp. 1874-1880. [11] Mohammad Reza Khoshravan et al., Design and Modal Analysis of Composite Driveshaft for Automotive Application, International Journal of Engineering Science and Technology, Vol. 3, No. 4, April 2011, ISSN : 0975-5462. [12] Mr. V. l. Narayana, Mr. D. Mojeswararao and Mr. M.N.V.R.L. Kumar “Optimization of composite drive shaft assembly and comparison with conventional steel drive shaft, Vol. 1 Issue 6, August – 2012. [13] Bhushan K. Suryawanshi, Prajitsen G. Damle “Review of Design of Hybrid Aluminum/Composite Drive Shaft for Automobile”, Volume-2, Issue-4, March 2013. [14] Bhirud Pankaj Prakash, Bimlesh Kumar Sinha. “Analysis of Drive Shaft” International Journal of Mechanical and Production Engineering, Volume- 2, Issue- 2, Feb.-2014, ISSN: 2320-2092. [15] K.V.N. Parvathi, CH. Prabhakara Rao, “Structural Design of Composite Drive Shaft for Rear-Wheel Drive Engine” Parvathi et al, 185 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 International Journal of Advanced Engineering Research and Studies, E-ISSN2249–8974. [16] S V Gopals Krishna, B V Subrahmanyam, and R Srinivasulu, “Finite Element Analysis and optimization of Automotive Composite Drive Shaft” International Journal of Engineering Trends and Technology (IJETT) – Volume 5 Number 7- Nov 2013. [17] Chirag B. Gandhi 1 Manthan Patel, “A Study Paper On Analysis And Comparison Of Composite Drive Shaft With Conventional Steel Drive Shaft” International Journal for Scientific Research & Development, Vol. 2, Issue 03, 2014, ISSN (online): 2321-0613. [18] T.Rangaswamy, S.Vijayarangan, R.A.Chandrashekar, T.K.Venkatesh and K.Anantharaman, “Optimal Design and Analysis of Automotive Composite Drive Shaft “International Symposium of Research Students on Materials Science and Engineering December 2002-04. [19] Belawagi Gireesh, Sollapur Shrishail B, V. N. Satwik, “Finite Element & Experimental Investigation of Composite Torsion Shaft” International Journal of Engineering Research and Applications, Vol. 3, Issue 2, March -April 2013, pp.1510-1517, ISSN: 2248-9622. 186 ELK Asia Pacific Journals – Special Issue 31. EXPERIMENTAL INVESTIGATION OF COMPARISON OF VCRS WITH PHASE CHANGE MATERIAL AS SODIUM SULPHATE (NA2SO4) AND SIMPLE VCRS SYSTEM Rahul Wandra1,Taliv Hussain2,Gaurav Singh Jaggi3, Sourabh4,Gourav Roy5 Department of Mechanical Engineering, Lovely Professional University Phagwara, Punjab (India) -144402 Email:
[email protected] Email:
[email protected] Phone no: 08283836492 ABSTRACT-A phase-change material (PCM) is a substance with a high heat of fusion which melts and solidifies at a certain temperature, is capable of storing and releasing large amount of energy. Heat is absorbed or released when the material changes from solid to liquid and vice versa; thus, PCMs are classified as latent heat storage (LHS) units. A PCM material helps in extracting heat from the evaporator by absorbing latent heat of vaporization from the compartment which is to be cooled which is the Evaporator. We will use a Na2SO4 (sodium sulphate) compound as a phase change material. It is an inorganic compound used to store energy within itself and release when required. It can efficiently absorb heat from the evaporator and release it outside the evaporative chamber. The Refrigeration system we used here is a simple vapour compression refrigeration system using R-134a as a refrigerant. On installing the Na2SO4 phase change material on the evaporator we observed a significant change in the COP of the system. The COP gets increased due to additional heat extracted by the inorganic compound by 22-26%. We observed this change for different ambient air temperatures. By using PCM we can also save the compressor work required by the refrigeration system. Keywords: Phase change material, Na2SO4, vapour compression refrigeration system, COP Proc. Of the Int. Conf: ARIMPIE-2015 INTRODUCTION Electrical energy consumption has become a worldwide research topic because refrigeration and air-conditioning systems consuming electrical energy approximately 15%. By using PCM we can save the compressor work required by the refrigeration system. An extensive review of the literature has been done on different refrigeration and heat pump systems in this paper. In vapour compression system there are four major components: evaporator, compressor, condenser and expansion device. Power is supplied to the compressor and heat is added to the system in the evaporator, where as in the condenser heat rejection occurs.. A standard vapour compression cycle consists of four processes viz. reversible adiabatic compression from the saturated vapour to the compressor pressure followed by a reversible heat rejection at constant pressure causing de-superheating and condensation. A PCM material helps in extracting heat from the evaporator by absorbing latent heat of vapourization from the compartment which is to be cooled. A phase-change material (PCM) is a substance with a high heat of fusion which melts and solidifies at a certain temperature, is capable of storing and releasing large amount of energy. Heat is absorbed or released when the material changes from solid to liquid and vice versa; thus, PCMs are classified as latent heat storage (LHS) units.PCM can be used in evaporater to store enery at daytime and can provide additional cooling effect along with the refrigerator. It can absorb heat from the evaporator which is left by the refrigerant. LITERATURE SURVEY A.S. Dalkilic and S. Wongwises [1], have studied the performance on a vapourcompression refrigeration system with refrigerant mixtures based on R134a, R152a, R32, R290, R1270, R600 and R600a was done for various ratios and their results are compared with R12, R22 and R134a as possible alternative replacements. The results showed that all of the alternative refrigerants investigated in the analysis have a slightly lower COP than R12, R22, and R134a for the condensation temperature of 50 °C and evaporating 187 ELK Asia Pacific Journals – Special Issue temperatures ranging between −30 °C and 10 °C. Refrigerant blends of R290/R600a (40/60 by wt. %) instead of R12 and R290/R1270 (20/80 by wt. %) instead of R22 are found to be replacement refrigerants among other alternatives.Vincenzo La Rocca and Giuseppe Panno [2], have analyzed and compared the performance of a vapour compression refrigerating unit operating with R22, and with three new HFC fluids, substituting the former according to Regulation No 2037/2000. Here the plant working efficiency was first tested with R22 and then with three new HFC fluids:R417a, R422a and R422d. It is analyzed that the performance with the new tested fluids did not result as efficient as when using R22.Yunho Hwang, Dae-Hyun Jin, Reinhard Radermacher [3], compared the performance of R290 with two other refrigerant mixtures (R404A and R410A) for a refrigeration system. They compared the environmental impact of these refrigerants, power consumption and life cycle climate performance. They found that the LCCP of R-290 is always lower than that of R404A. The LCCP of R-410A is lower than that of R-290 as long as the annual emission is kept below 10%. It was concluded that R-410A has less or equivalent environmental impact as compared to R-290 when safety (toxicity and flammability), environmental impact (climate change), cost and performance (capacity and COP) are considered. Ciro Aprea, Angelo Maiorino, Rita Mastrullo [4], compared the performance of R22 and its retrofit R422D. They compared the performance of vapour compression refrigeration system at different working conditions and compared the performance with AHRI standard. They observed cooling capacity, the electrical power absorbed, the COP and other variables characterizing the working of the plant. They showed that the cooling capacity for R422D was lower than for R22, while the electrical power absorbed with R422D was higher than that with R22 and the COP of R422D was lower than R22 Proc. Of the Int. Conf: ARIMPIE-2015 used to measure the inlet and outlet pressure of compressor. Temperatures of refrigerant and circulation air at different points are recorded with RTD PT100 type thermocouples. OBSERVATION TABLE Table 1: Result obtained by using PCM (Na2So4) and simple VCRS Parameter s Unit and Symbo l Simple VCRS system VCRS with ( Na2So4) PCM At At At At 27° C 30° C 27 °C 30 °C Suction Pressure Bar 0.16 0.46 0.40 0.31 Discharge Pressure Bar 8.71 8.52 9.13 10.11 Evaporato r Outlet Temperat ure Degre e Celsiu s(°C) 10.8 8 11.1 5 13.88 14.11 Compress or Outlet Temperat ure Degre e Celsiu s 43.1 0 49.1 4 42.51 44.20 30.4 5 30.6 6 33.1 30.1 1.9 1.25 0.9 1.8 200 200 200 200 (°C) Condense r Outlet Temperat ure Degre e Celsiu s (°C) Current Amper e (A) MEASURING DEVICES Ammeter and voltmeter are used to measure the electrical current and voltage of input power respectively. The bourdon pressure gauges are Voltage Volt(V ) 188 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 EXPERIMENTAL SETUP Table 2: Result of the experiment at ambient air temperature 27°C The Experimental setup used in this procedure is a simple Vapour Compression Refrigeration system. The components are evaporator, compressor, expansion device and condenser. An Air cooled condenser is used in the condensation process of the condenser. The copper tubes are well insulated to prevent any convection effect from the tubes. Shell and tube type evaporator is used where copper tubes has been used in it. A 220 V reciprocating compressor is used. The refrigerant used in this system is a Freon R134-a. Expansion device used here is a capillary tube of very less diameter. Apart from the components used in a simple vapour compression refrigeration system, we have installed a phase change material in the evaporator of the refrigeration system. The Phase change material used is an inorganic compound Na2SO4. This Phase change material is installed in the evaporator section where it absorbs the heat from within the evaporator. The refrigerant starts from the compressor where it is compressed and then fed to the condenser where the refrigerant gets converted into liquid state. Then the liquid refrigerant is passed over into the evaporator through a capillary tube for expansion purpose CALCULATIONS AND RESULTS A. Compressor Work Wc = V * I = mref* (h2 –h1) Performance result of Air Conditioner (Tamb27°C) Simple VCRS VCRS Parameter Unit system with (Na2So4) PCM Compressor work Wc COP 380 192 3.42 4.76 Watt ------------ Table 3: Result of the experiment at ambient air temperature 30°C Performance result of Air Conditioner (Tamb30°C) Simple VCRS VCRS Parameter Unit system with (Na2So4) PCM 376 250 Compressor Watt work Wc 3.73 4.53 COP ------------ B. Mass flow rate of refrigerant mref C. Cooling effect produced Qr = mref* (h1 –h4) D. COP = Where, h1 = enthalpy of refrigerant at inlet compressor in kj/kg (1) h2 = enthalpy of refrigerant at exit compressor in kj/kg (2) h3 = enthalpy of refrigerant at exit of condenser kj/kg (3) h4 = enthalpy of refrigerant at entry evaporator in kj/kg (4) REFERENCES of of the of [1] Cengel, Y., and Boles, M., 1994. Thermodynamics: An Engineering Approach,McGraw-Hill, New York. [2] Pouraghaie, M., Atashkari, K., Besarati, S., and Nariman-Zadeh, N., 2010,“Thermodynamic Performance Optimization of a Combined Power/Cooling Cycle,” Energy Convers. Manage., 51(1), pp. 204–211. 189 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 [3] A.S. Dalkilic, and S. Wongwises, “A performance comparison of vapour-compression refrigeration system usingvarious alternative refrigerants,International Communications in Heat and Mass Transfer, 37, pp. 1340–1349, 2010. [4] James M. Calm, “Emissions and environmental impacts from air-conditioning and refrigeration systems,” International Journal of Refrigeration, 25, pp. 293–305, 2002. [5] Refrigeration and Air-conditioning by R.S.Kurmi [6] T. Chikahisa, H. Matsuo, T. Murayama, Investigations on compact and high-performance heat pumps for cold regions (2nd report, estimation of performance improvement by combining heat storage system with conventional GHP), Transactions of the Japan Society of Mechanical Engineers, Part B 62 (596) (1996) 1591-1598 (in Japanese). 190 ELK Asia Pacific Journals – Special Issue 32. BEHAVIOUR OF POLYMER MATRIX COMPOSITE UNDER DIFFERENT ENVIRONMENTAL CONDITIONS Saurabh Pathak, Shubendra Nath Shukla,Vikas Chaudhary, Kaushalendra Kr Dubey Department of Mechanical & Automobile Engineering, Sharda University, Greater Noida, U.P. I Email:
[email protected] Abstract Polymer-matrix composites (PMC) have been used for a variety of structural memberships for chemical plants and airplanes, since they have outstanding performances, such as lightweight and good fatigue properties. To hold the long-term durability and to estimate the residual life of the composites under some hostile environments, it is an important issue to clarify the facture and/or the failure mechanism in each service conditions. The main concern of this paper will be to examine the causes of degradation of polymeric components under different environment. Keywords-PMC, Tensile Loading Freezing Point., Proc. Of the Int. Conf: ARIMPIE-2015 area of discussion in this guide. Also known as FRP- Fibre Reinforced Polymers- these materials use a polymer-based resin as the matrix, and a variety of fibres such as glass, carbon and aramid as the reinforcement. 1.2 FRP Composites - A generic FRP system will constitute a matrix and reinforcement in a fibrous form. The use of fibre as high performance engineering materials is based on three important characteristics; (i) A small diameter with respect to its grain size or other micro structural unit. This allows a higher fraction of the theoretical strength to be attained than is possible in a bulk form. This is a direct result of the so-called “size-effect’’, which is , the smaller the grain size, the lower the probability of having the impurities in the material. It has been shown, that the strength of the carbon fibre decreases as its diameter increases. The general trend may be linear or non-linear. (ii) A high aspect ratio (length/diameter), which allow a very large fraction of the applied load to be transferred via the matrix to the strong and stiff fibres. (iii) A very high degree of flexibility, which is really a characteristic of a material that has a high modulus and a small diameter. This flexibility permits use of variety of techniques for making composites with these fibers [2]. 1. Introduction 1.3 Reinforcement material Composite material, as the name suggest, is a combination of two or more materials which are combined on a macroscopic scale to form a useful material. The constituent materials have significantly different physical and chemical properties and remain separate in the final structure. These materials are ideal for structural applications where high strength-to-weight and stiffness-to-weight ratio are required. Composites are hybrid materials made of a polymer resin reinforced by fibres, combining the high mechanical and physical performance of the fibres and the appearance, bonding and physical properties of polymers [1]. 1.1 Polymer Matrix Composites (PMC’s) These are the most common and will the main The primary function of fibres or reinforcements is to carry load along the length of the fibre to provide strength and stiffness in one direction. Reinforcements can be oriented to provide tailored properties in the direction of the loads imparted on the end product. Reinforcements can be both natural and man-made[3]. Many materials are capable of reinforcing polymers. Some materials, such as the cellulose in wood, are naturally occurring products. Most commercial reinforcements, however, are manmade. Of these, by far the largest volume reinforcement measured either in quantity consumed or in product sales, is glass fibre. Other composite reinforcing materials include carbon, aramid, UHMW (ultra high molecular weight) polyethylene, polypropylene, polyester 191 ELK Asia Pacific Journals – Special Issue and nylon. Carbon fibre is sometimes referred to as graphite fibre. More specialized reinforcements for high strength and high temperature use include metals and metal oxides such as those used in aircraft or aerospace applications. 2. Methodology There are a wide variety of processes available to the composites manufacturer to produce FRP products. Each of the fabrication processes has characteristics that define the type of products to be produced FRP laminates can be made by a number of primary manufacturing processes for composite materials.[4] Hand lay-up, compression molding, pultrusion, Resin Transfer Molding (RTM), Vacuum Assisted Resin Transfer Molding (VARTM) etc. can be used to make laminates. A survey of the facilities available was carried out and it was decided to make the laminate using the hand lay-up technique. [5] Proc. Of the Int. Conf: ARIMPIE-2015 Volume fraction is an important parameter that gives a fair amount of idea about the degree of reinforcement that has been done by the addition of fibres. The mechanical properties of the FRP composites strongly depend on the fibre-volume fraction. Burnout test was performed to find out the value of fibre-volume fraction. The burning process was accomplished in the Muffle furnace. The weighing of the specimen was carried out on digital weighing machine having an accuracy of 0.001gm. [7] The samples to test by burnout were taken from different section of the GFRP composite laminate to randomize any sort of error. Volume fraction of GFRP is carried on muffle furnace. This procedure is known as burn out operation or ignition loss method. According to (American society of testing material) ASTM D2584 standard test method for ignition loss method cured reinforced resin. Three samples GFRP are taken according to standard and then heated at a temperature of 650C for ten minutes and it was then cooled to room temperature and its mass was determined. [8] After burn out operation volume fraction of the ranged from 34.75 to 36.12 so the average glass fibre volume fraction comes 35.71% .[9] 4. ENVIRONMENTAL CONDITIONS AND IMPACT Fig. 1 Hand Lay Up Process a). Effect of NaOH The material selected for the fabrication of flat plate mold was mild steel. The flat plate mold was fabricated using the standard processes of shaping, drilling and welding. Grinding of the faces of both the plates was done in order to attain high degree of surface finish. Surface finish of the faces becomes important to impart a smooth surface on the laminates. The matching of the two flat plates of the mold was done using the dowels and nut-bolt arrangement was used to apply. [6] and NaoH Photo 2.1Effect of H2SO4 3. Testing and Result 192 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Fig 2.2 Percentage variation of tensile strength with decrease in weight while dipping in NaoH Fig.2 6. Effect of freezer environment on tensile strength d).Effect of brine solution Fig2.3Effect of NaoH on tensile strength with respect to time b).Effect of H2SO4 Fig2.7 Effect of brine solution on tensile strength 5. CONCLUSIONS Fig 2.4Effect of H2SO4 on tensile strength with respect to time c). Effect of freezer conditions Fig.2.5 Variation of tensile strength with increase in weight in freezing condition The effect of various environmental conditions on tensile strength of glass fibre reinforced composite were investigated. (i) The tensile strength decreases and percentage reduction increases after every time interval because of attack of NaOH on epoxy resin. (ii) The effect of acid will increase the percentage reduction because inter phase deboning, and matrix swelling of PCM material cause reduction in tensile strength. (iii) It is observed that the tensile strength in freezing conditions is almost the same as in sukhna lake water. Degradation in tensile strength is low in freezing condition because of low moisture uptake so Polymer matrix can be used in low temperature applications. 193 ELK Asia Pacific Journals – Special Issue (v)The PMC’s material when subjected to NaOH solution showed the maximum percentage Reduction in tensile strength whereas minimum percentage reduction was found for exposure to freezing environmental condition. Proc. Of the Int. Conf: ARIMPIE-2015 aged fibre glass polyester composite” Materials and Design 30 (2009) 271–274 REFERENCES 1. Gu Huang and Hongxia Sun, “Effect of water absorption on the mechanical properties of glass/polyester composites” Materials and Design 28 (2007) 1647–1650 2. M. Raghavendra1, C.M. Manjunatha, “effect of moisture on the mechanical properties of GFRP composite fabric material” International Symposium of Research Students on Material Science and Engineering (2004) 3. Rui Miranda Guede, “Prediction of longterm behaviour of composite materials” Computers and Structures 76 (2000) 183194 4. Alaattin Aktas, “Sea water effect on pinnedjoint glass fibre composite materials” Composite Structures 85 (2008) 59–63 5. T.J. Myers, “Environmental stress-corrosion cracking of fibreglass: Lessons learned from failures in the chemical industry” 142 (2007) 695–704 Journal of Hazardous Materials 6. D. Olmos, “The nature of the glass fibre surface and its effect in the water absorption of glass fibre/epoxy composites. The use of fluorescence to obtain information at the interface”, Composites Science and Technology 66 (2006) 2758– 2768 7. Yunn-Tzu Yu, “Modeling long-term degradation due to moisture and oxygen in Polymeric matrix composites” Materials Science and Engineering (2008) 8. A. PAILLOUS and C. PAILLER, “Degradation of multiply polymer-matrix composites induced by space environment”( 1993) 9. Abdalla F. H., “Determination of volume fraction values of filament wound glass and carbon fibre reinforced composites” VOL. 3, NO. 4, AUGUST 2008 10. Salar Bagherpour, “Effects of concentrated HCl on the mechanical properties of storage 194 ELK Asia Pacific Journals – Special Issue 33. STUDY OF FLOW FIELD OF RIVER FOR HYDRO KINETIC TURBINE INSTALLATION Mishra, A.1 MED, KEC, Ghaziabad.
[email protected] Kumar, A.1 MED, KEC, Ghaziabad
[email protected] Singhal, M.1 MED, KEC, Ghaziabad
[email protected] Abstract:An optimized location finding in river, for efficient power generation through hydrokinetic turbine, is very important. Power generation through hydrokinetic turbine is mainly depend upon the flow velocity of the river and also flow features and channel morphology which greatly influence the installation of hydrokinetic turbine. In the present work, the flow field of river has been studied through the fluent software to identify the optimum location for the installation of hydrokinetic turbine. The discharge data of a selected river has been analyzed and discussed. It also has been investigated the effect of flow field on the power generation from hydrokinetic turbine. Index terms: River Flow Field, Hydrokinetic turbine, CFD I. Introduction The study of flow field of river is very important to investigate various flow field parameters in water resource system, river control development works for life and works of humans, analysis of river mechanics problem, design of hydraulic structure etc. various studied has been made to analyses the river flow field with respect to earlier said working fields. In addition to computation-control parameters, certain other parameters must be defined. These principally describe the conveyance properties of the channels. Although these parameters Proc. Of the Int. Conf: ARIMPIE-2015 cannot be measured directly, they can be derived from certain measured data. They depend principally upon the physical properties of the channels of the rivers. Generally the Mountain Rivers or glaciers river have very steep flow and complex bed geology. To study of the flow field for any geological and artificial structure within the flow must be analyzed and it is very important to simulate the flow field for outcome and results of that particular flow structure and parameters of river. A paper has been discussed the flow field of the ice cubes and the boulders in river through the IR scanner shown in figure 1 [2]. [1]. In figure 1 the temperature field around the ice boulder has been shown. Fig.1. Flow patterns captured with the IR camera, using ice cubes as tracers [2] As it discussed above the flow field of any flow stream or river gives the compete knowledge about the flow structure and flow behavior around any boulders or any bluff body. The flow field for river has been investigated for many geological and environmental purposes but there is a lack of study to estimate the river field to correlate the energy generation devices in river such as in stream and free flow hydrokinetic turbines. A river flow parameters also needed for water power generation through hydrokinetic turbines In present research work, the study of flow field of selected rivers has been estimated and analyzed. And require parameters of the hydrokinetic turbine has been correlated with the river flow field model. It has been also discussed the flow pattern of the river field around the any structure such as the bluff body which is similar to the hydrokinetic turbine mainly Darrius 195 ELK Asia Pacific Journals – Special Issue turbine. A similar flow field study for river and bluff body assumption as hydrokinetic turbine has been done. II. Literature review The study of flow field of river is an important task for various studies related to flow interaction of the water stream to the boulders, channel geology, other artificial structure such as river weirs, bridges etc. various literatures are available, in which the study of flow field investigated for river morphology and geology. However, there is a lack of work has been done to investigate the flow field of river for energy generation device such as hydrokinetic turbine. Here, following literature has been studied in which the various parameter of the river flow field are investigated and analyzed. Khassaf et.al [3] investigated the flooding in the river could be prevented using the cross sectional area of river by adjusting its geology. The results demonstrate that the area at Al Am'arah city at distance 17.5 Km from upstream (cross section 30) could be subjected to flooding at High Flow, therefore, it is recommended to adjust cross sections to prevent the flooding in this area. At last, Calibration of the hydrodynamic model is achieved in a study reach using the observed data (water stage) along AL Msharah River and show that a good agreement. Birjukova, O. et.al. [4] Studied the confluent of two flow stream at the same elevation of river bed. The stagnation zone, which is characterized by the close-to-zero stream wise and crosswise velocities, is formed at the upstream junction corner. The tributary flow acts as an obstacle for the main channel flow, creating two down- ward orientated velocity fields that are displaced towards the center flume as the flow proceeds downstream. The separation zone, characterized by the upstream flow motion and, hence, the flow recirculation, limits the effective lateral flow cross-section, which results in the added acceleration of the mainstream flow in the post confluence channel. The maximum stream wise velocities in the central upper region of the accelerated flow are Proc. Of the Int. Conf: ARIMPIE-2015 ≈1.4 times larger than the corresponding velocities at the undisturbed approach flow upstream the confluence. The non-dimensional length and width of the separation zone seem to be of the order of magnitude of that observed by Biron et al. (1996)[5], indicating that the main channel aspect ratio may not influence the relative size of the stagnation zone. This conclusion requires future confirmation. An analytical technique has been discussed Bhattacharya et. al. [6] to analyses the ground water stream and surface water stream within same catchment area. Flow net model is used to determine the hydrologic interaction in the riveraquifer system along the river. Flow line is an imaginary line that traces the path that a particle of groundwater would follow as it flows through an aquifer (Fetter, 1994). The flow nets were constructed based on water table and river level measurements. Two sites were chosen for these measurements, one was located in the upper section of Ogun River while two was located at the lower section. This study revealed an intricate groundwater flow pattern that is controlled by lithological and structural factors that creates zone of surface and ground water interaction. These zones are often referred to as ecotone zones within the hypoheic ecosystems. Surface water - groundwater interaction can be investigated by using flow-nets and hydrodynamic methods. Research that will cover the ecological aspects can only be carried out through methods of the measurement that are extremely complex, resources intensive and also require extensive technical knowledge. A non-uniform such as river flow or approach flows has been studied Lei et.al. [7] to analyze the flow past the bluff body (rectangular cylinder). The simplest case of a non-uniform flow for the investigation of the velocity gradient effect is the uniform-shear flow, which has a linear distribution of the longitudinal velocity component along the transverse direction [8]. A numerical procedure is applied to lid-driven flows in square and polar cavities, and a uniform laminar flow past a circular cylinder. The results are compared with experimental and/or other numerical studies. Good agreement is achieved 196 ELK Asia Pacific Journals – Special Issue with these benchmark problems. Then, the shear flow past a circular cylinder with Reynolds numbers from 80 to 1000, and with shear parameters up to 0.25, is calculated. III. Proc. Of the Int. Conf: ARIMPIE-2015 Auxiliary relations Methodology A computational methodology has been adopted in this paper. ANSYS is used for geometry and meshing. Fluent is used for post processing. The flow was assumed to be 2-dimensional. Rivers NANDAKINI and LACHEN have taken. Computations have done on a two dimensional domain.Discharge of these rivers for year 2000 have been takenand given in table [9]. IV. Result Discussion Pressure, velocity and turbulent intensity for both rivers are shown below. K-omega model is used to explore the turbulent intensity. LACHEN River Table 1 RIVER NANDAKINI LACHEN Fig. 2 DISCHARGE 2468 CUSEC 2.4 CUMEC 500m 20 m . Fig. 4 Residual Plot Fig. 3Computational Domain An incompressible SIMPLE finite volume code was used.The k-omega model was used to simulate the river flow for considered contour. It is due to association of turbulence in the river flow. Following equation has been used to calculate the river contour flow parameters. Eddy viscosity Turbulence kinetic Energy Fig. 5Static Pressure Plot Specific dissipation rate Closure Coefficients 197 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Fig. 9 Turbulent Kinetic Energy River NANDAKINI Residual Plot Fig. 6Pressure Contour According to residual plot all equations converged in 700 iterations. And the velocity contour is shown in fig 10.Pressure contour shows that in the starting of domain dynamic pressure is large and it will decreases in the direction of flow.so at the entry of the flow pressure can be harmful for hydrokinetic turbine and it can developed the cavitation or pitting action at some specific region of turbine. Fig. 7 Velocity Contour Fig. 10 Residual Plot Fig. 8Turbulent Intensity Fig.11 Static Pressure Plot 198 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Fig. 15 Turbulent Kinetic Energy Fig. 12 Pressure Contour The flow velocity in both river cases it has been observed that there slight changes in velocity at 80 percent of upper region of river. However, the turbulence intensity is large enough at entry of the river. Fig. 13Velocity Contour V. Utilization of river hydrokinetic turbine flow field for Energy generation through the water resources is very important to meet the energy requirement in river side industries and inhabitants. A recent technology in free flow turbine or hydrokinetic turbine converts flowing water energy to electric energy which can tap the energy from open channel flow. It can be installed in stream through anchorage system, fixed bed system and pontoon boat system. However the installation of hydrokinetic turbine requires the knowledge of river or stream flow parameters such as velocity, turbulence and pressure contour. According to bet’z law the energy generation equations for hydrokinetic turbine is given as follows. 𝑷𝒐𝒘𝒆𝒓 = 𝟏 𝟐 𝝆𝑨𝑽𝟑𝑪𝒑 Where, ρ is water density, A is swept area of turbine, V is the velocity and Cp is power coefficient (Max= 0.59) Fig. 14Turbulent Intensity It can be seen that the most influencing parameter is velocity of the flow for power generation. It also has been seen in various literatures that the turbulence in flow also effect the drag and drift coefficient of turbines wings which affect the power generation of the turbine( Hernandez and Crespo) [8]. And many other parameters such as TSR (Tip speed ratio), thrust etc. are correlated to the Reynolds number (Re) of the flow. So it can be say that the installation of the turbine in river flow requires flow field data to input of the turbine and hydrokinetic turbine such as Darrius and Savonius turbine are behave as bluff body in the river stream. 199 ELK Asia Pacific Journals – Special Issue So the hydrokinetic turbine installed where available stream velocity meets the requirement of the particular turbine design. In case of Darrieus turbine the lift and drag forces are needed to extract the more energy from the flowing water. However, the Savonius turbine requires only drag force of stream and lift force creates instability of the turbine. It can be used the above discussed result of flow field of river to estimate the adequate location of the turbine. VI. Conclusion In development of the river resource system and utilization of these resources effectively, study of flow field for of river or open channel natural streams are necessary. Energy extraction from the free flow water is one of therenewable energy harvesting method. Hydrokinetic device can install at appropriate location of the river therefore device can tap energy efficiently. A study of flow field of river has been done and following conclusions are made as follows. I. At the entrance of the river or channel device should not be install. II. The Depth Rivers (> 5m) the velocity does not affect the installation and it can be installed above 1-2 m depth. III. As turbulence contour the pressure at entry of stream has increased and could develops the cavitation in turbine and components IV. As per the future aspects the detailed study of the river flow field with appropriate boulders and cascade turbine analysis are suggested. Proc. Of the Int. Conf: ARIMPIE-2015 in Al-Msharah River." Kufa journal of Engineering 1.1 (2014). [4]. Birjukova, Olga, et al. "Three dimensional flow field at confluent fixed-bed open channels." Proc. River Flow. 2014. [5]. Biron, P., J. Best, & A. Roy (1996). “Effects of bed discordance on flow dynamics at open-channel confluences.” J. Hydraulic Engng 122 (12), 676–682. [6]. Bhattacharya, Amartya Kumar, and G. AkinBolaji. "Fluid flow interactions in Ogun River, Nigeria." IJRRAS 2.2 (2010): 173180. [7]. Lei, Chengwang, Liang Cheng, and Ken Kavanagh. "A finite difference solution of the shear flow over a circular cylinder." Ocean Engineering 27.3 (2000): 271-290. [8]. Hernandez, J.andA. Crespo, Aerodynamics CalculationofthePerformance of HorizontalAxis Wind TurbinesandComparisonwith ExperimentalResults.1987. 11(4):p.177‐187. [9]. Central Water Commission URL http://www.cwc.nic. in/main/webpages/publications.html References: [1]. Schaffranek, Raymond W. "A Flow Model for Assessing the Tidal Potomac River." Applying Research to Hydraulic Practice. ASCE, 1982. [2]. Moustakidis, Iordanis, Athanasios Papanicolaou, and AchilleasTsakiris. "The Effect of Boulder Spacing on Flow Patterns around Boulders under Partial Submergence." (2012). [3]. Khassaf, Saleh I., Jaffar S. Maatooq, and Shahla A. Nasrallah. "Mathematical Modeling of water surface at Unsteady Flow 200 ELK Asia Pacific Journals – Special Issue 34. A REVIEW ON THE PERFORMANCE OF THE NANOFLUID BASED SOLAR COLLECTORS - SOLAR ENERGY Kapil Sharma1, Satnam Singh1, Manvendra Yadav2*, Sanjay Yadav2, Naveen Mani Tripathi3 1 School of Mechanical Engineering, Lovely Professional University, Phagwara, Punjab 2* Department of Mechanical Engineering, ITS Engineering College, Greater Noida 3 Department of Mechanical Engineering, BenGurion University of Negev, Beer-Sheva, Israel ABSTRACT Using nanofluids as an innovative kind of liquid blend with a trivial volume fraction (in percent) of nanometer-sized solid particles in suspension is a fairly a novel arena or idea. The objective of this presented review paper is to inspect the performance of the nanofluid-based solar collector (NBSC). In past few years for a number of experimental and industrial thermal engineering systems solar energy has proven to be the best input energy source. The scarcity of fossil fuels and environmental contemplations motivated the researchers to utilize alternative energy sources such as solar energy, wind energy, tidal energy etc. Therefore, it is essential to boost the performance of the solar thermal engineering systems. Because of better rheological properties nanofluids are utilized to build up the performance of conventional solar thermal engineering systems. Therefore, major part of this presented review paper lays a main emphasis to investigate the effects of nanofluids on the performance of solar collectors. Some proposals are also given to use the nanofluids for future work in different solar thermal engineering systems such as parabolic trough systems (PTS), solar thermoelectric cells and finally, the challenges of using nanofluids in solar energy devices are reviewed in brief. Keywords: Solar energy, solar thermal systems, nanofluids, solar thermometric cells, parabolic trough system, solar collector. Proc. Of the Int. Conf: ARIMPIE-2015 I. INTRODUCTION In recent years, a tremendous growth in the energy sector especially in the field of solar energy is observed due to increased scientific developments. Several developments and examinations were carried out in the area of solar energy. Scientific developments have been carried out in the area of concentrated solar power (CSP). Solar collectors converts the solar radiation into heat and then transfer this heat to a medium i.e. heat transfer fluid (HTF). The solar energy is used to carry out the heating or cooling processes [1]. Generation of Sustainable energy is identified as the most important challenge faced by our society today. The demand of electricity consumption is increased day by day and the production of electricity has become a key issue in the industry. Electricity adds a main segment to the world’s total energy demand and is growing faster than liquid fuels, natural gas, and coal, petroleum and natural gas which are used to produce steam in boilers of power plants and these power plants stand a majority load in the electricity power plant in the whole world. The heat exchangers that are used to transform the solar radiation energy to internal energy of the transport medium are known as solar thermal collectors. Non-concentrating solar collectors can be used if an excessive amount of solar radiation is concentrated on a fairly lesser collecting area [2]. Over the past 10–15 years concentrated solar energy has become the input for an increasing number of experimental and commercial thermal systems [3]. For solar collectors the utilization of nanofluids as a working fluid is a relatively a novel idea. Various researchers are interested to develop the various aspects of solar energy because of it is readily available in nature [2]. In direction to upsurge the effectiveness or performance of solar collectors, one of the most appropriate method is to change the working fluid like water, ethylene glycol by higher thermal conductivity fluids like aluminum oxide, copper oxide. The blend of base fluids like water or ethylene glycol with suitable nanoparticles like silicon oxide or aluminium oxide are called nanofluids. In comparison with conventional heat transfer fluids nanofluids exhibits exceptional heat transfer properties [1].Common type of base fluids such as water, ethylene 201 ELK Asia Pacific Journals – Special Issue glycol, therminol VP-1 and heat transfer oil plays a vital role in several industrial processes such as power generation, heating or cooling processes, chemical processes, and microelectronics. However, the above mentioned base fluids exhibits low heat transfer properties and thus cannot reach high level of heat exchange rates in thermal engineering devices. A way to solve this problem is to use ultra-fine powdered nanoparticles as mentioned suspended in common fluids like water or ethylene glycol to increase their thermal conductivity. The suspension of powdered form nano-sized particles (metallic or non-metallic oxides) ranging from 1 to 100 nm in a conventional base fluid as discussed above is known as a nanofluid [4]. Therefore, we can say that the nanofluids are the suspensions of metallic or nonmetallic nanoparticles in a base fluid like water or ethyl alcohol [5]. Nanofluids exhibits better stability, rheological properties, and considerably higher thermal conductivities. In recent years both experimental and theoretical work was done by various scientists or researchers to examine the effects of nanofluids on the enhancement of heat transfer in thermal engineering devices, [3]. The remarkable features of nanofluids are increase in liquid thermal conductivity, liquid viscosity, and heat transfer coefficient. Proc. Of the Int. Conf: ARIMPIE-2015 nanoparticles in the working fluid, the efficiency increases remarkably for low values of volume fraction of nanoparticles However, it was found that the inclusion of more nanoparticles is not beneficial because the efficiency remains approximately constant for a volume fraction higher than 2%. Investigations were also carried out regarding the effects of nanoparticles size and collector geometry on the collector efficiency. The results also revealed that the efficiency increases slightly with an increase in the size of nanoparticles. The collector efficiency increases as the collector’s height increases and reaches up to the value of 80 %, and with the length factor the efficiency firstly increases with length and then gradually falloffs. It was observed that the rise of collector efficiency to the rise in attenuation of sunlight passing through the collector due to the nanoparticles inclusion leads to the increase of collector efficiency. On comparison, the DASC using nanofluid as a working fluid have 10 % efficiency higher than that of the conventional flat plate collector using water as a working fluid. The results revealed that the efficiency increases slightly with an increase in the size of nanoparticles. (Figure 2). II. EXPERIMENTAL INVESTIGATIONS Tyagi et al. [6] worked on theoretical and numerical observations to study the effects of different criterion that is nanoparticle size, volume fraction, collector geometry on the efficiency of a low-temperature nanofluid based direct absorption solar collector (DASC).In this paper water based aluminum nanoparticles Al2O3 taken as a working fluid (i.e. composition of water and aluminum nanoparticles). Numerical modelling of DASC was also done by using two dimensional heat transfer analysis. The variation of collector efficiency as a function of the particle volume fraction (0.1% to 5%), particle size, collector geometry was studied experimentally. The variation of collector efficiency as a function of the particle volume fraction (%), where the volume fraction varies from 0.1% to 5% shown in Figure1.The results revealed that by the inclusion of Fig.1 Effect of particle volume fraction on collector efficiency [6] 202 ELK Asia Pacific Journals – Special Issue Fig.2 Effect of nanoparticles size on collector efficiency [6] Otanicar et al. [7] carried out an experimental and theoretical investigations to study the effects of different nanofluids such as carbon nanotubes, graphite, and silver on the performance of a direct absorption solar collector (DASC). The investigations were carried out to check the variation of collector efficiency as a function of volume fraction for different nanomaterials mentioned above. The DASC data are compared with the conventional collector configuration where the solar energy is absorbed on a black plate surface. It was concluded that by the inclusion of small amounts of nanoparticles leads to the remarkable improvement of the collector efficiency. The efficiency increases up to approximately 0.5% of volume fraction. After a volume fraction of 0.5%, the efficiency begins to level off and even fall slightly with increasing volume fraction. Proc. Of the Int. Conf: ARIMPIE-2015 Figure 3: Variation of collector’s efficiency with volume fraction [7] By using graphite nanoparticles of size 30 nm, the performance of DASC over a conventional flat surface absorber was increased up to 3% which was considered to be the maximum enhancement in its performance. In case of silver particles, the main difference in the steady-state efficiency between nanofluids occurred when the size of these particles is between 20 and 40 nm. It was found that when the size of silver nanoparticles reduces from 40 nm to 20 nm efficiency enhancement of 6 % was observed. The collector efficiency as a function of volume fraction was plotted for silver graphite and CNT nanoparticles in figure 3. It was seen that as the size of nanoparticles increases, the collector efficiency decreases. Taylor et al. [8] carried out theoretical & experimental investigations regarding the applicability of nanofluids in high flux solar collectors and to compare the performance of nanofluid-based concentrating solar thermal system with a conventional system. The results indicated that the usage of a nanofluid as the working fluid in the receiver enhance the efficiency by 10%. It was seen that Collector efficiency enhancement of 5%–10% is possible with a nanofluid used as the working fluid in the receiver. It was concluded that using graphite/therminol VP-1 nanofluid for 10–100 MWe power plants, with volume fractions approximately up to 0.001% or less could be advantageous. The authors estimated that in a solar resource like Tucson, Arizona combining solar thermal power tower with a nanofluid receiver with the capacity of 100 MWe operating, could generate $3.5 million more per year. It was observed that, nanofluids are not expected to be appropriate for using as the working fluid for parabolic dish or trough solar thermal systems, but further optimization or cost reductions might increase their range of applicability. Taylor et al. [9] carried out theoretical and experimental investigations to study the optical property characterization of various nanoparticles such as graphite, silver, copper, gold, and aluminum suspended in water and 203 ELK Asia Pacific Journals – Special Issue therminol-VP1 as the base fluids to determine their potential to be utilized in direct absorption solar collectors (DASC). To determine the optical property of nanofluids like graphite, aluminum measurement and modelling techniques were used. For several concentrations of aqueous graphite nanofluids extinction coefficients were studied by using modelling and experimental methods. The results showed that approximately 95% of incoming sunlight coming from the sun can be absorbed by a nanofluid having thickness greater than equal to 10 cm with very small nanoparticle volume fractions (less than 0.00001 or 10 ppm). Thus, nanofluids could be utilized to absorb sunlight with a small amount of viscosity and/or density. It was concluded that absorption is generally due to the nanoparticles at shorter wavelengths and due to the base fluids at longer wavelengths. Natarajan & Sathish [10] carried out an investigation to study the role of nanofluids in solar water heater. The objective of this study was to examine and compare the heat transfer properties of the nanofluids with the conventional fluids. During this investigation water based Multiwall carbon nanotubes (MWCNTs) were used as nanofluids with volume fraction in percent taken as 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2. For the preparation of CNTs sodium dodecyl sulphate (SDS) was used as a surfactant. Sodium dodecyl sulphate was used to obtain stable nanofluids. It was found that for the stable CNT dispersion SDS surfactant proves to be a suitable dispersant. Transient hot-wire method was used to measure the thermal conductivities of nanofluids. It was concluded that the thermal conductivity of water-based MWCNT nanofluid increases as a function of volume fraction of MWCNTs. At a volume fraction of 1.0% the thermal conductivity of nanofluid increased up to 41%. The comparison between the experimental data for MWCNT in deionized water was done and the values were calculated from Hamilton–Crosser model. It was concluded that the measured values of thermal conductivity is greater than those calculated from Hamilton–Crosser model (HDC). It was also concluded that if nanofluids are used as a heat transport medium, it increases the efficiency of the traditional solar water heater. Proc. Of the Int. Conf: ARIMPIE-2015 Khullar et al. [11] carried out theoretical & numerical investigation regarding the application of nanaofluids as the working fluid in concentrating parabolic solar collectors. In this paper mathematical modelling of heat transfer and flow aspects of the linear parabolic solar collectors had been done. Al-water based nanofluid was used as the working fluid and to solve the equations numerically FDM (finite difference method) technique has been used. Evaluation and comparison of the two dimensional temperature field, optical and thermal efficiencies, and mean-outlet temperatures had been done for both conventional parabolic collectors utilizing water as a working fluid and nanofluid based collectors using nanofluid as a working fluid. In order to achieve the desired output temperature the effect of various operating criterion such as concentration ratio, receiver length, fluid velocity, volume fraction of nanoparticles taken into consideration. The results indicated that in terms of thermal and optical efficiencies and higher outlet temperatures under same working conditions the collector using nanofluid as a working fluid has a better performance as compare to the conventional collector. The results also showed that the inclusion of aluminium nanoparticles into the base fluid (water) significantly improves its absorption characteristics. Sani et al. [12] carried out an investigation about the optical and thermal properties of nanofluids as a function of the nanoparticle concentration consisting in aqueous suspensions of single wall carbon nanohorns (SWCNH). The characteristics of these nanofluids were evaluated in view of their use as sunlight absorber fluids in a solar device, hence characterization of SWCNH was done in aqueous suspensions as new nanofluids for the utilization in the field of solar energy. It was found that the thermal conductivity of the nanofluids was higher than the water used as the operating fluid. According to spectral transmission measurement SWCNHs play an important role in improving the photonic properties of the fluid, leading to a major increase of the light extinction level even at very 204 ELK Asia Pacific Journals – Special Issue low concentrations. At the investigated concentrations up to 10% rise in the thermal conductivity was observed. For the optimization of heat transfer efficiency, optical and thermal properties of the nanofluid provides valuable information to the sunlight collector designer. It was concluded that for efficiency enhancement the usage of SWCNH water nanofluid as absorber in solar devices appears a very promising step. Sani et al. [13] carried out an experimental investigation to study the potential of carbon nanohorn (CNH)-based suspensions for solar thermal collectors. In this paper the optical characterization of new fluid made up of singlewall carbon nanohorns (SWCNH) and ethylene glycol as a base fluid for solar energy applications were studied. In optical characterization to measure the potential of SWCNH-glycol suspension as direct sunlight absorbers, the optical properties of the nanofluid were examined as a function of the nanoparticle concentration. The measured spectral transmission showed that SWCNHs play an important role to enhance the photonic properties of the fluid, leads to a remarkable growth of the light extinction level even at very small concentrations. To evaluate the differences between SWCNHs and conventional commercial carbon forms, i.e. Carbon-black particles the obtained results had been compared with glycolbased amorphous carbon suspensions It was found that Carbon nanohorn (CNH) plays an vital role to increase the sunlight absorption with respect to the pure base fluid & SWCNHs spectral features are far more favourable than those of amorphous carbon-black particles for the specific application. It was concluded that, the use of SWCNH-glycol based nanofluid as direct absorber or working fluid in solar devices can be beneficial for increasing the collector efficiency and compactness of thermal solar devices, reducing both environmental impact and costs. Mercatelli et al. [14] carried out an investigation to study the scattering and absorption properties of carbon nanohorn-based nanofluids consisting in aqueous suspensions of Proc. Of the Int. Conf: ARIMPIE-2015 single wall carbon nanohorns for solar energy applications. In order to use them as direct sunlight absorber fluids in solar devices the characteristics of these nanofluids were assessed. The investigation was carried out for nanohorns of different morphologies (dahlia-like, bud-like and seeds-like) and for suspensions prepared with different amounts of surfactant, hence measurements of extinction and absorption coefficients on Single Wall Carbon Nanohorn (SWCNH) suspensions as a function of the nanoparticle morphology was done. The differences in optical properties induced by carbon nanoparticles compared to those of pure water lead to a considerably higher sunlight absorption with respect to the pure base fluid. Scattering results indicating that the portion of light scattered by SWCNH suspensions was smaller than 5%. This means that approximately up to 95% of light was directly absorbed. Therefore, nanohorns suspensions behave as perfect absorbers for NIR wavelengths (833 nm) or for longer wavelengths. Finally it was concluded that for new-generation solar collectors SWCNHs seems to be very promising as inventive direct sunlight absorbers in the field of Solar Energy. Han et al. [15] carried out an experimental investigation about the thermal properties of carbon black aqueous nanofluids for solar absorption. In this paper carbon black nanofluids were prepared by dispersing the pre-treated carbon black powder into distilled water. During investigation optical properties of carbon black powder and nanofluids, photo thermal properties, rheological behaviours, thermal conductivity of carbon black nanofluids were measured. The volume concentration of nanofluids taken as 4.4%, 5.5%, 6.6%, 7.7% and wavelength ranges from 200-2500 nm. It was found that with high-volume fraction the nanofluids have better photo thermal properties which shows better solar energy adsorption properties. In the wavelength range from 200 to 2,500 nm both carbon black powder and nanofluids have good absorption characteristics. The results showed that the shear viscosity increases as the volume fraction increases and decreases as the temperature increases at the same shear rate and the thermal conductivity of 205 ELK Asia Pacific Journals – Special Issue carbon black nanofluids increases as the volume fraction and temperature increases. Finally it was concluded that, carbon black nanofluids have good absorption ability of solar energy and can effectively increase the solar absorption efficiency, hence carbon black nanofluids have high potentials for the utilization in solar application. Yousefi et al. [16] carried out an experimental investigations to study the effects of Al2O3/water nanofluid on the efficiency of a flat-plate solar collector. The effect of using water as the working fluid, Al2O3 nanofluid as the working fluid without surfactant and with surfactant on the efficiency of solar collector was investigated. Triton X-100 was used as a surfactant. Two different weight fractions i.e.0.2% and 0.4% of the nanofluid taken into account with diameter of the particles taken as 15 nm. The effect of mass flow rate also taken into consideration. The mass flow rates were taken as 1, 2, 3 lit/min. their results showed that: 1. With 0.2% weight fraction (wt.) Al2O3 nanofluid the efficiency of the solar collector is greater as compare with the water by 28.3%. 2. The efficiency of the collector using 0.2% weight fraction Al2O3 nanofluid is higher as compared to 0.4 % weight fraction for a wide range of the reduced temperature parameter. 3. By using Triton X-100 as a surfactant the maximum enhanced efficiency of the collector is 15.63%. Yousefi et al. [1] carried out an examination using the same experimental setup as in their previous work (Yousefi et al., 2012a), to study the effects of water–Multi wall carbon nanotubes (MWCNT)-H2O nanofluid on the efficiency of the flat plate collector. The effect of using water as the working fluid, MWCNT nanofluid as the working fluid without surfactant and with surfactant on the efficiency of solar collector was investigated. Triton X-100 used as a surfactant. The authors examined the effect of two different weight fractions i.e.0.2% and 0.4% of the nanofluid with diameter of the particles taken in the range from 10 to 30 nm. The effect of mass flow rate also taken into account. The mass flow rates were taken as 1, 2, and 3 lit/sec. their results shows that: Proc. Of the Int. Conf: ARIMPIE-2015 1. The efficiency of the collector by using of MWCNT–H2O nanofluid as a working fluid without surfactant is remarkably increased for 0.4 % weight fraction of nanofluid, 2. With 0.2 % weight fraction of MWCNT nanofluid with surfactant collector efficiency increases and without surfactant the efficiency decreases. 3. For small values of reduced temperature differences parameter, the efficiency of collector is increased by increasing the mass flow rate. Beyond these small values, the efficiency gets a reversed trend. Yousefi et al. [17] carried out an experimental investigation to study the effect of pH variation of MWCNT–H2O nanofluid on the efficiency of a flat-plate solar collector. The experimental work carried out by using weight fraction of 0.2 % with different pH values i.e. 3.5, 6.5, 9.5. Triton X-100 used as additive. The diameter of MWCNT taken as 10-30 nm. With mass flow rate of 0.0333 kg/s the efficiency of the flat-plate solar collector with MWCNT nanofluid as a working fluid at three pH values (3.5, 6.5, and 9.5.) was compared with water. It was observed that if the temperature differences higher than the mean temperature difference, the efficiency for pH = 3.5 is greater than that for pH = 9.5. On the other hand, if the temperature differences lower than the mean temperature difference, the efficiency of the flat-plate solar collector for pH = 9.5 is greater than that for pH = 3.5. It was also observed that, the absorbed energy parameter for pH=9.5 is higher than that of pH=3.5 and 6.5. Similarly, the removed energy parameter for pH=6.5 was higher than pH=9.5 and pH=3.5. Among these values pH values removed energy parameter of pH =3.5 was lower. From the experimental results it was concluded that, more differences between the pH of nanofluid and pH of isoelectric point leads to more improvement in the collector efficiency as the pH of the isoelectric point is 7.4 for MWCNT. Saidur et al. [18] carried out an experimental investigation to study the effect of using nanofluid as working fluid for direct solar collector. The objective of this study was: 206 ELK Asia Pacific Journals – Special Issue (1) To investigate the appropriateness of nanofluid as a volumetric absorber. (2) To discover the radioactive properties of the base fluid and the nanoparticle. (3) To determine the effect of nanoparticle sizes and volume fractions for nanofluid as well as comparing its transmissivity of light. The extinction coefficient of aluminum (Al) nanoparticle suspended in water as a base fluid was investigated and evaluated by changing nanoparticle size and volume fraction. It was seen that the nanoparticle size has negligible impact on the optical properties of nanofluid. On the other hand, the extinction coefficient of water based aluminium nanofluid is linearly proportional to volume fraction. The authors observed that direct solar collector is expected to provide excellent optical properties and improved thermal transfer by utilizing nanofluids as a volumetric absorber. At shorter wavelength aluminum nanoparticle shows very strong extinction coefficient and peak at a wavelength of 0.3 μm. In spite of a lower extinction coefficient at longer wavelength, aluminium nanoparticle can be utilized to improve the light absorption ability of water at the visible and shorter wavelength region. It was observed that the improvement is promising within 1.0% volume fraction and is showing suitable enhancement to solar absorption, aluminium nanofluid is seems to be good solution for direct solar collector as a volumetric absorber. Khullar et al. [19] studied the environmental impact of nanofluid based concentrating solar water heating system. This paper examines the potential of the nanofluid-based concentrating solar water heating system (NCSWHS) as a substitute to systems based on fossil fuels. Therefore, to save fossil fuels which are presently being widely used for water heating purposes the concept of NCSWHS and its potential was examined. It was found that the proposed water heating system has relatively better performance characteristics in comparison with the conventional flat plate collectors. The NCSWHS system also seems to be the best solution for fuel savings and it also promises the reduction of CO2 emission so far as it substitutes for fossil fuel water heaters. It was seen that:- Proc. Of the Int. Conf: ARIMPIE-2015 1. The common water heating system of concentrating type would be more efficient and cost effective than flat plate collector. 2. The main advantage of NCSWHS is that it is being energy efficient. 3. Higher output temperatures can be attained by using NCSWHS hence it significantly reduces greenhouse gas emissions and save enormous amount of fossil fuels. Khullar et al. [20] carried out theoretical investigations to study a nanofluid-based concentrating parabolic solar collector (NCPSC) and the results obtained were compared with the experimental results of conventional concentrating parabolic solar collectors operating under same conditions. Aluminium nanoparticle with 0.05 vol. % suspended in Therminol-VP-1 as the base fluid was used for the analysis. The results showed that the thermal efficiency of NCPSC compared to a conventional parabolic solar collector is about 5–10% higher under the similar weather conditions. The theoretical results indicated that the nanofluid-based concentrating parabolic solar collector has the potential to harness solar energy in a more efficient manner as compared to a conventional parabolic trough. It was observed that in order to get the desired output in terms of thermal efficiency and maximum outlet fluid temperatures, nanoparticle shape, size, and material need to be optimized and to transform this new concept of harvesting solar radiant energy into a commercial reality mathematical analysis needs to be validated with experimentation. Chougule et al. [21] carried out an experimental investigation to check the performance of nanofluid charged solar water heater using solar tracking system. In this investigation two identical flat plate collectors using heat pipes were fabricated. The nanoparticles used in the present study are CNT having diameter 10-12 nm and for the preparation of nanofluid the concentration of nanoparticles taken as 0.15% by volume. Experimentations were carried in two steps i.e. by changing the collector’s angle from Indian Standard i.e. normal angle 3l° to 207 ELK Asia Pacific Journals – Special Issue maximum performance angle of solar collector 50° with fixed position and other step is keeping the collectors on tracking mechanism. The effect of tilt angle, Solar Tracking System, & effect on average efficiency and on heat loss factor [Tm Ta /It] was observed. After the observation of CNTs nanofluid used as working fluid it was concluded that a very low quantity of nanoparticles results in a better performance and has remarkable potential as working fluid in high performance thermosyphon heat pipe collectors. It was also concluded that at 50° tilt angle working fluids gave better performance as compared to standard normal angle in both conditions (fixed and tracking) & average efficiencies are increased 12% and 11 % for water and nano working fluid at 31.50° tilt angle while 7% and 4% respectively at 50° tilt angle using tracking system, hence Solar tracking system adds an advantage to improve the efficiency in both water as well as nano working fluid solar heat pipe collector and also each of tilt angle for solar heat pipe collector. De Risi et al. [22] mathematically done the modelling and optimization of transparent parabolic trough collector based on gas-phase nanofluids as a working fluids. To directly absorb the solar energy a new concept of solar Transparent Parabolic trough Collector (TPTC) working with gas-based nanofluid as heat transfer fluid was suggested and examined. The model of the geometrical, thermal and fluid dynamic aspects of the TPTC was developed mathematically in order to attain global performance and to describe the main geometrical and operational criterion of the TPTC. In inclusion, to optimize the performance of the solar collector a genetic algorithm optimization was used. Numerical results revealed that the gas-based nanofluids when combine with Transparent Parabolic trough Collector can be an effective substitute to conventional systems such as synthetic oils or molten salts. Simulation of the gas based nanofluids absorption showed that a complete absorption of the solar spectrum within the diameter of the receiver tube is attained by a correct composition (0.25% CuO and 0.05% Ni). Proc. Of the Int. Conf: ARIMPIE-2015 The results also indicated that the maximum TPTC solar to thermal efficiency is 62.5%.for a nanofluid outlet temperature of 650°C and a nanoparticles volume concentration of 0.3%. Chaji et al. [23] carried out an experimental investigation to check the Thermal Efficiency of Flat Plate Solar Collector (FPSC) using TiO2/Water nanofluid. In this investigation to study the effects of different nanoparticle concentrations of TiO2 in water as base fluid a small flat plate solar collector (FPSC) was fabricated and tested, hence the effect of nanofluid on solar collector efficiency was evaluated for different mass flow rates (36, 72 and 108 lit/m2.hr). Three levels of TiO2 nano particles concentrations i.e. 0.1%, 0.2%, 0.3% (without using surfactants) were examined and the results were compared with those of water. It was concluded that the increase of mass flow rates of base fluid inside the solar collector enlarged the index of total collector efficiency area under the curves up to 15.7%. Also, adding the nano particles to water improved the index of collector efficiency -area under the curve between 2.6 and 7% relative to base fluid at the same flow rate. Tiwari et al. [24] presents a comprehensive overview on thermal performance and environmental impact analysis of solar flat plate collector for water heating using Al2O3 water based nanofluid. The effect of utilizing the Al2O3 nanofluid as absorbing medium in a flatplate solar collector was studied. The effect of mass flow rate and particle volume fraction on the efficiency of collector was also investigated. The mass flow rate taken as 30, 60, 90, and 120 in lit/hr and the volume concentration taken as 0.5, 1.0, 1.5, and 2.0 in percent were taken into account. It was concluded that using the 1.5% optimal particle volume fraction of Al2O3 nanofluid increase the thermal efficiency in comparison with water as working fluid by 31.64%. Maddah et al. [25] carried out an experimental investigation to study the effect of silver and aluminium oxide nanoparticles on thermo physical properties of nanofluids. Thermal conductivity, electrical conductivity, and 208 ELK Asia Pacific Journals – Special Issue viscosity are the thermo physical properties of nanofluids. For investigation the nominal diameters of Al2O3 and Ag nanoparticles taken as 40 and 20 nm. Nanofluids of various volume concentrations 0.25% to 5% taken into consideration at a temperature of 15°C. The nanofluid was prepared by dispersing aluminium oxide and silver nanoparticles in distilled water and then sonication process was done. It was concluded that 1. The viscosity and thermal conductivity of nanofluids increases as volume fraction of nanoparticles increases. 2. The electrical conductivity of nanofluids increases linearly with an increase in the volume fraction of the aluminium oxide and silver nanoparticles. It was observed that higher the concentration of nanofluids, higher is the viscosity. On the other hand, electrical conductivity of aluminium oxide and silver nanofluid is significantly greater than that of the base fluid. Proc. Of the Int. Conf: ARIMPIE-2015 thermoelectric cells installed on the focal point of the dish. In this way the effects of different nanofluids with various mass flow rates on the efficiency of the solar thermoelectric cell can be studied [4]. Fig.7 The experimental set-up proposed for using nanofluids in thermoelectric cells [4] IV. CHALLENGES III. FUTURE WORK Following parameters are the possible challenges in the application of nanofluids in solar thermal systems. Use of nanofluids in solar energy is still an inventive idea. Based on our survey these proposals will be helpful for the development and use of nanofluids in the solar thermal devices. 1. High cost Solar thermal devices have high cost of nanofluids because of difficulties in production. 3.1. Parabolic trough systems [4] Only a literature work has been done on parabolic trough collectors using FDM technique, hence some experimental studies should perform to check the effects of nanofluids on the performance this system 3.2. Solar thermoelectric cells Recently the evolvement of solar thermoelectric systems comes into existence. The thermoelectric cells can be used to transform the solar energy to electricity due to the temperature difference between two hot and cold surfaces. A greater temperature difference between the hot and cold surfaces of the thermoelectric cell leads to a bigger electricity production. Experimental setup to investigate the effects of nanofluids on the performance of such systems is suggested [4]. Authors suggested a construction in which a dish concentrates the solar radiation on the 2. Instability and agglomerating Instability and agglomeration of the nanoparticles is also a big problem. Hence, nanofluids should not be used with natural circulation (such as thermosiphons) where there is no pump to circulate the fluid, in solar systems with. It should be also noted that for high temperature gradients the agglomeration of nanoparticles seems to be more serious [26]. Therefore, exact investigations are needed for an appropriate selection of a nanofluid for applications in high temperatures [4]. 3. Pumping power and pressure drop Using a nanofluid with higher viscosity compared to the base fluid leads to the increase of pressure drop and consequently the increases in the required power for pumping. For example, Researchers found during their experiments that 209 ELK Asia Pacific Journals – Special Issue the pressure drop under a turbulent regime increases with an increase in volume fraction of TiO2/water nanofluid. 4. Erosion and corrosion of components Existing of nanoparticles in nanofluid may lead to corrosion and erosion of thermal devices in a long time[4]. Researchers recently investigated the effects of nanofluid flow effects on erosion and corrosion of metal surfaces. They conducted their experiments for TiO2, Al2O3, SiC, ZrO2 nanoparticles with water as the base fluid where the nanofluids flow in pipes with three different materials, i.e., aluminum, copper and stainless. They concluded that the nanofluids have no effect on the erosion of the stainless pipe, while the aluminum pipe has highest erosion. They also found that ZrO2 and TiO2 nanoparticles lead to highest erosion while SiC nanoparticles results in lowest erosion. V. CONCLUSION Nanofluids are foremost fluids containing nanosized particles and have been used to enhance system performance in many thermal engineering systems. This paper conferred a review Performance of the Nanofluid Based Concentrated Solar Collector - Solar Energy. The experimental and numerical studies for solar collectors showed that in some cases, the efficiency could increase remarkably by using nanofluids. It was found that using a nanofluid with higher volume fraction always is not the best option. Hence, it is suggested that the nanofluids in different volume fractions should be examined to find the optimum volume fraction. It is also seen that the available literature works give different results on the effects of particle size on the efficiency of the collectors. It will be valuable to carry out an experimental work on the effect of particle size on the collector efficiency. Modelling and optimization of transparent parabolic trough collector based on gas-phase nanofluids was also carried out and the numerical results have shown that gas-based nanofluids combined with TPTC can be an effective alternative to conventional systems such as synthetic oils or molten salts that have shown different application problems in existing plants. Simulations results also show that that the maximum TPTC solar to thermal Proc. Of the Int. Conf: ARIMPIE-2015 efficiency is 62.5%, for a nanofluid outlet temperature of 650 °C and a nanoparticles volume concentration of 0.3%.There are many proposals are conferred to develop the use of nanofluids in different solar systems such as parabolic trough systems, solar thermoelectric cells, etc. The critical challenges on the use of nanofluids in solar systems arrangements consist of high costs of production, agglomeration problems, instability, increased pumping power and erosion are mentioned. Such type of issues would be reduced with the development of nanotechnology in the future. VI. REFERENCES 1. Yousefi T., Veisy F., Shojaeizadeh E., Zinadini S., (2012b), An experimental investigation onthe effect of MWCNTH2O nanofluid on the efficiency of flat plate solar collectors, “Experimental Thermal and Fluid Science”,vol. 39, pp. 207–212. 2. Saidur R., Meng T.C., Said Z., Hasanuzzaman M., Kamyar A., (2012), Evaluation of the effect of nanofluidbased absorbers on direct solar collector, “International Journal of Heat and Mass Transfer”, vol. 55, issues 21– 22,pp. 5899–5907. 3. Taylor R.A., Phelan P.E., Otanicar T.P., Walker C.A., Nguyen M., Trimble S., and Prasher R., (2011a), Applicability of nanofluids in high flux solar collectors, “Journal of Renewable and Sustainable Energy”, vol. 3, issue 2, pp. 023104-1 to 15. 4. Mahian O., Kianifar A. , Kalogirou S. A., Pop I. , Wongwises S., (2013), A review of the applications of nanofluids in solar energy, “International Journal of Heat and Mass Transfer”, vol. 57, Issue 2, pp. 582–594. 5. Yousefi T., Veisy F., Shojaeizadeh E., Zinadini S., (2012a), An experimental investigation on the effect of Al2O3H2O nanofluid on the efficiency of flatplate solar collectors, “Renewable Energy”,vol. 39, pp. 293-298. 6. Tyagi H., Phelan P., Prasher R., (2009), Predicted efficiency of a lowtemperature nanofluid – based direct 210 ELK Asia Pacific Journals – Special Issue 7. 8. 9. 10. 11. 12. 13. 14. absorption solar collector, “Journal of Solar Energy Engineering”, vol. 131, pp. 041004-1 to 7. Otanicar T.P., Phelan P.E., Prasher R.S., Rosengarten G., and Taylor R.A., (2010), Nanofluid based direct absorption solar collector, “Journal of Renewable and Sustainable Energy”, vol. 2, issue 3,pp. 033102-1 to 13. Taylor R.A., Phelan P.E., Otanicar T.P., Walker C.A., Nguyen M., Trimble S., and Prasher R., (2011a), Applicability of nanofluids in high flux solar collectors, “Journal of Renewable and Sustainable Energy”, vol. 3, issue 2, pp. 023104-1 to 15. Taylor R.A., Phelan P.E., Otanicar T.P., Adrian R., Prasher R.P., (2011b), Nanofluid optical property characterization: towards efficient direct absorption solar collectors, “Nanoscale Research Letters”, vol. 6, issue 1, pp. 225. Natarajan E. & Sathish R., (2009), Role of nanofluids in solar water heater, “Int J Adv Manuf. Technol.”, special issue, doi 10.1007/s00170-008-1876-8. Khullar V., Tyagi H.,(2010), Application of nanofluids as the working fluid in concentratingparabolic solar collectors, “37th National & 4th International Conference on Fluid Mechanics & Fluid Power”, IIT Madras, Chennai, India, Dec. 16–18, Paper No. FMFP2010-179. Sani E., Barison S., Pagura C., Mercatelli L., Sansoni P., Fontani D., Jafrancesco D. and Francini F., (2010), Carbon nanohorns-based nanofluids as direct sunlight absorbers, “journal optic express”, vol. 18, issue. 5, pp.1-9. Sani E., Mercatelli L., Barison S, Pagura C. , Agresti F., Colla L., Sansoni P.,(2011), Potential of carbon nanohornbased suspensions for solar thermal collectors, “Solar Energy Materials & Solar Cells”, vol. 95, Issue 11, pp. 2994–3000. Mercatelli L., Sani E., Fontani D., Zaccanti G., Martelli F., Di Ninni P.,(2011), Scattering andabsorption Proc. Of the Int. Conf: ARIMPIE-2015 15. 16. 17. 18. 19. 20. 21. properties of carbon nanohorn-based nanofluids for solar energy applications, “Journal of the European Optical Society-Rapid Publications”, vol. 6, pp.11025-1 to 5. Han D., Meng Z., Wu D., Zhang C., Zhu H.,(2011), Thermal properties of carbon black aqueous nanofluids for solar absorption,“Nanoscale Research Letters”,vol. 6,pp.1-7. Yousefi T., Veisy F., Shojaeizadeh E., Zinadini S., (2012a), An experimental investigation onthe effect of Al2O3H2O nanofluid on the efficiency of flatplate solar collectors, “Renewable Energy”,vol. 39, pp. 293-298. Yousefi T., Shojaeizadeh E., Veysi F., Zinadini S., (2012c), An experimental investigation on the effect of pH variation of MWCNT–H2O nanofluid on the efficiency of a flat-plate solar collector, “Solar Energy”, vol. 86, Issue 2, pp. 771-779. Saidur R., Meng T.C., Said Z., Hasanuzzaman M., Kamyar A., (2012), Evaluation of the effect of nanofluidbased absorbers on direct solar collector, “International Journal of Heat and Mass Transfer”, vol. 55, issues 21– 22,pp. 5899–5907. Khullar V., Tyagi H., (2012a), A study on environmental impact of nanofluid based concentrating solar water heating system, “International Journal of Environmental Studies”, vol. 69, issue 2, pp. 220–232. Khullar V., Tyagi H., Phelan P.E., Otanicar T.P., Singh H., Taylor R.A.,(2012b), Solar energy harvesting using nanofluids-based concentrating solar collector, “Journal of Nanotechnology in Engineering and Medicine”, vol. 3 ,pp. 031003-1 to 9. Chougule Sandesh S., Pise Ashok T., Madane Pravin A.,(2012), Performance of nanofluid charged solar water heater by solar tracking system, In: Proceedings of “IEEE-International Conference On Advances In Engineering, Science And Management 211 ELK Asia Pacific Journals – Special Issue 22. 23. 24. 25. 26. Proc. Of the Int. Conf: ARIMPIE-2015 (ICAESM -2012)” March 30, 31,2012,pp.247-253. De Risi A., Milanese M., Laforgia D.,(2013), Modelling and optimization of transparent parabolic trough collector based on gas-phase nanofluids, “Renewable Energy”,vol. 58,pp.134139. Chaji H., Ajabshirchi Y., Esmaeilzadeh E., Heris Saeid Z., Hedayatizadeh M. , Kahani M., (2013), Experimental study on thermal efficiency of flat plate solar collector using TiO2/Water nanofluid, “Modern Applied Science” published by Canadian Centre of Science and Education, vol. 7, issue 10,pp.60-69. Tiwari A. K., Ghosh P., Sarkar J., (2013), Solar water heating using nanofluids-a comprehensive overview and environmental impact analysis, “International Journal of Emerging Technology and Advanced Engineering”, vol. 3, Issue 3:ICERTSD 2013, pp. 221-224. Maddah H., Rezazadeh M., Maghsoudi M., NasiriKokhdan S., (2013), The effect of silver and aluminium oxide nanoparticles on thermophysical properties of nanofluids, “Journal of Nanostructure in Chemistry”, vol. 3, pp.1-6. Taylor R.A., Phelan P.E., Adrian R.J., Gunawan A., Otanicar T.P.,(2012), Characterization of lightinduced, volumetric steam generation in nanofluids, “International Journal of Thermal Sciences”,vol.56,pp. 1-11. 212 ELK Asia Pacific Journals – Special Issue 35. STUDY OF THE HARDNESS & THE MICROSTRUCTURE OF AISI 1050 MEDIUM CARBON STEEL AFTER HEAT TREATMENT PROCESSES Sanjeev Kumar Jaiswal Department of Mechanical Engineering, School of Engineering & Technology, Sharda University, Greater Noida (U.P), India Email ID: -
[email protected] T.Sharma Department of Fuel & Mineral Engineering, Indian School of Mines, Dhanbad ,India. Email ID:
[email protected] Rajesh M. Department of Mechanical Engineering Sharda University, Greater Noida Email ID:
[email protected] Vineet Kumar Department of Sharda University, Greater Noida Email ID:
[email protected] Abstract: Main Objective is to Study the Effect on the Hardness & microstructure of Sample Grade of AISI 1050 medium carbon steel. Heat Treatment Processes Such As Annealing, Normalizing, and Hardening is carried on AISI 1050 medium carbon steel & after treatment aims to perform hardness testing on the treated and untreated work samples. Full annealing is done at 800˚ C, 825˚ C & 850 ˚ C for soaking time 10 minutes, 15 minutes & 20 minutes respectively. Sub critical annealing is done at 675˚ C & 700˚ C for soaking time 10 minutes & 15 minutes respectively. The present work investigates the effect of cooling on the microstructure and hardness of AISI 1050 Carbon Steel. Sample size with a Proc. Of the Int. Conf: ARIMPIE-2015 diameter 20 mm were heat treated for soaking time of 10 minutes, 15 minutes & 20 minutes at 800˚ C, 825˚C & 850 ̊ C respectively and were quenched in three different medium- (1) cold water (2) hot water & (3) vegetable oil to study the effect of various quenching medium on the hardness of AISI 1050 medium carbon steel. Keywords: – AISI 1050 Carbon Steel, Annealing, Hardening, Heat Treatment, Normalizing and Quenching Medium. I. INTRODUCTION Steels have been used since the Iron Age and their importance in the development of the industry have been enormous. Steels are the most important alloys utilized as structural material. They are straightforwardly related to engineering. The Microstructure of most steels is well known by now as well as the effect of heat treatments in changing their mechanical properties [1]. For instance, the hardness of AISI 1050 carbon steel could vary from approximately 20-58 HRC depending on its heat treatment [1]. The differences in mechanical properties of given steel are the result of different microstructure formed during cooling. This statement generally means that the highest hardness in the iron carbon systems is obtained due to a diffusion less transformation called marten site formation and lowest hardness is obtained due to a diffusion transformation, which causes the ferrite and /or pearlite formation by a eutectoid reaction. Both marten site obtained during rapid cooling and ferrite-pearlite obtained during slow cooling or near the equilibrium, come from austenite [1]. Effect of heat treatment on the mechanical properties for rolled medium carbon steel studies by [2].Similarly, the effect of cooling rate on Hardness and Microstructure of AISI 1020, AISI 1040 and AISI 1060 Steels [3]. II. MATERIALS AND METHODS The chemical composition of AISI 1050 Carbon steel 213 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Table 1 Steel Type C Mn Si Fe AISI 1050 .55 .65 .25 98.55 The material used in this study is 20mm diameter AISI 1050 Carbon Steel. The AISI 1050 steel cut 20mm length with the help of power-hexa machine and remove the burr with the help of grinding machine. The samples were heated at 800oc for 10 minute to remove the potential residual stresses before micro hardness tests. The samples were heat treated at 800°C,825°C & 850°C for soaking time 10 minutes,15minutes & 20 minutes respectively were cooled by three different quenching mediums cold water, hot water & vegetable oil. III. EXPERIMENTAL SETUP A.OBJECTIVE The objective of the present investigation is to i. ii. iii. iv. v. vi. vii. Hardening the surface of medium carbon steel. Evaluate the change in the hardness of medium carbon steel. Further harden the medium carbon steel by quenching. Explore the effects of tempering on hardened steel samples. Explore the effects of soaking time on hardened steel samples. Analyzing the micro structure of medium carbon steel. Studying and comparing the change in the hardness after hardening different compositions of steel by different quenching medium. Fig.1 Muffle furnace B. METHODOLOGY i. Take grade AISI 1050 containing C 0.55 {medium carbon steel} for preparation of sample with diameter 20mm. ii. Preparation of 25 samples of 20mm length for heat treatment. {hardening and tempering} iii. Hardening in different medium a) cold water b) hot water c) oil iv. Setup Muffle furnace temperature 800°C, 825°C & 850° C v. Measure hardness before quenching vi. Measure hardness after quenching vii. Similarly measure the effect of soaking time in 10, 15 & 20 minutes C. Preparation of samples for hardness testing • • Take grade AISI 1050 containing C 0.55 {medium carbon steel} for preparation of sample with diameter 20mm. Preparation of 25 samples of 20mm length for heat treatment. {hardening and tempering} 214 ELK Asia Pacific Journals – Special Issue Fig.2 Samples of AISI 1050 Carbon Steel with diameter 20mm Proc. Of the Int. Conf: ARIMPIE-2015 Fig. 5 The microstructure of AISI 1050 BHT (10X) Fig.6 The microstructure of AISI 1050 BHT (10X) Fig.3 Rockwell Hardness Testing Machine D.MICROSCOPY STUDY Fig.7 Microstructure of AISI 1050 BHT on Rockwell B (10X) Fig.4 The microstructure of AISI 1050 carbon steel (10X) Based on fig.4, fig.5, fig.6 & fig7 shows the various microstructure of AISI 1050 Carbon steel before heat treatment 215 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Fig.8 The microstructure of hardening samples at 800˚ C For cold water for 10 min (10X) Fig.12The microstructure of AISI 1050 steel at 850˚ C in hot water for 20 min (10 X) Fig 9 The microstructure of 800°c hardening temperature for 10 min in cold water (10X) Fig. 13The microstructure of hardening samples at 825˚ C for oil for 15 min RHB(10 X) Based on fig8, fig.9, fig.10, fig.11, fig.12& fig.13 shows the microstructure of AISI 1050 Carbon steel heat treatment conditions for hardening temperature for different soaking time intervals Fig.10 The microstructure of 800°C hardening for15 min in cold water (10X) Fig.11 The microstructure of 850°C hardening for 20 min in cold water (10X) Fig.14 The microstructure of sub critical annealing at 675˚ C for 15 min RHB (4X) 216 ELK Asia Pacific Journals – Special Issue Fig.15 The microstructure of sub critical annealing at 700˚ C for 20 min RHB(4X) Fig.16 The microstructure of full annealing at 800˚ C for 10 min RHB (4X) Based on fig.14, fig.15& fig.16 shows the microstructure of AISI 1050 Carbon steel heat treatment conditions for full annealing & sub critical annealing Proc. Of the Int. Conf: ARIMPIE-2015 Fig.18 The microstructure of normalizing samples at 825˚ C for 15 min RHB (4X) Fig.19 The microstructure of normalizing samples at 850˚ C for 20 min RHB (4X) Based on fig.17, fig.18 & fig.19 shows the microstructure of AISI 1050 Carbon steel heat treatment conditions for normalizing IV Result & discussion Table 2.Heat Treatment conditions for hardening of AISI 1050 Carbon steel- Fig.17 The microstructure of normalizing samples at 800˚ C for 10 min RHB (4X) Hardening Temperature 800˚C 825˚C 850˚C 800˚C 825˚C 850˚C 800˚C 825˚C 850˚C Quenching Media Cold Water Cold Water Cold Water Cold Water Cold Water Cold Water Cold Water Cold Water Cold Water Soaking Time 10 10 10 15 15 15 20 20 20 RHB 93.5 95.5 98 91.91 92.91 93.5 89.5 92.58 93.916 217 RHC 58.5 60.86 62.17 51.5 55.46 57.67 41.87 44.95 47.5 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 Table 4. Hardness Properties For Samples Subjected hardening temperature Fig.20 Graph of hardness for different hardening temperature in cold water for different soaking time Hardening Temperature 800˚C 825˚C 850˚C 800˚C 825˚C 850˚C 800˚C 825˚C 850˚C Quenching Media Oil Oil Oil Oil Oil Oil Oil Oil Oil Soaking Time 10 10 10 15 15 15 20 20 20 RHB 82.33 83.67 85.5 80.67 81.5 83.67 78.86 80.75 81.5 RHC 20.58 21.23 22.55 18.69 20.03 21.75 14.25 18.45 20.01 Table 3. Hardness Properties For Samples Subjected hardening temperature Hardening Temperature 800˚C 825˚C 850˚C 800˚C 825˚C 850˚C 800˚C 825˚C 850˚C Quenching Media Hot water Hot water Hot water Hot water Hot water Hot water Hot water Hot water Hot water Soaking Time 10 10 10 15 15 15 20 20 20 RHB 85.25 87.67 89.5 80.56 82.25 84.5 76.5 80.67 82.58 RHC 33.75 35.57 37.25 28.67 30.5 32.75 25.83 27.95 29.83 Fig.22 Graph of hardness for different hardening temperature in oil for different soaking time Table 5. Heat treatment conditions for full annealing process for AISI 1050 Carbon steelFull annealing 800 Soaking time 10 Hardness(RHB) 825 15 57.74 850 20 58.02 56.68 Quenching medium Furnace cooling Furnace cooling Furnace cooling Table 6. Heat treatment condition for sub critical annealing process for AISI 1050 Carbon steelFig.21 Graph of hardness for different hardening temperature in hot water for different soaking time Subcritical Annealing 675 Soaking time Hardness(RHB) Quenching medium 15 76.44 700 20 69.65 Furnace cooling Furnace cooling 218 ELK Asia Pacific Journals – Special Issue Table 7. Heat treatment conditions for normalizing process for AISI 1050 Carbon SteelNormalizing 800 Soaking time 10 Hardness (RHB) 60.124 825 15 64.828 850 20 67.332 Quenching medium Air cooling Air cooling Air cooling Proc. Of the Int. Conf: ARIMPIE-2015 Int J of Physics Sciences, vol.4(9), [4] Ashish Bhateja, A. V. (2012). Study the Effect on the Hardness of three Sample Grades of Tool Steel i.e. EN-31, EN-8, and D3 after heat treatment Processes Such As Annealing, Normalizing, and Hardening & Tempering. The International Journal of Engineering and Science (IJES), Vol.1 No.2, 253259. [5] Atik, E. Y. (March 2003, Vol.36). The effects of conventional heat treatment and boronizing on abrasive wear and corrosion of SAE 1010, SAE 1040, D2 and 304 steels. Tribology International , 155-161. [6] Demirkol, K. G. (1999). Effect of case depth on fatigue performance of AISI 8620 carburized steel. International Journal of Fatigue , Vol. 21, 207–212. [7] Enver Atık, U. Y. (2003). The effects of conventional heat treatment and boronizing on abrasive wear and corrosion of SAE 1010, SAE 1040, D2 and 304 steels. Tribology International , Vol.36, 155–161. [8] A. (2013). Heat Treatment ofEN-8 Steel Casting Samples. India: metalworld. [9] R. Balasubramaniam, (2010). Callister's Materials Science and Engineering. India: Wiley India Pvt. Ltd. V Conclusions i. ii. iii. iv. v. vi. vii. The micro structural characteristics of these steels were parameterized by the pearlite volume (dark region) fraction. The percentage of pearlite changes with change in carbon content of steels. The hardness is strongly influenced by the temperature and time. The value of hardness decreases with retention of samples in the furnace for a longer period. For AISI 1050 steels higher hardness value have been obtained when quenched in cold water and lowest hardness value have been obtained when quenched in vegetable oil. The microstructure of AISI 1050 carbon steel in case of normalizing process is pearlite. The microstructure of AISI 1050 Carbon steel in case of annealing is coarse pearlite. References [1] G.Krauss, Steels: Heat Treatment and processing principles, ASM International, OH, USA, 1989. [10] T. V. Rajan, C. S. (2011). Heat Treatment Principles and Techniques. India: PHI. [2] OJAY 1st publication PDF- Effect of Heat Treatment on the mechanical properties of rolled medium carbon steel. [11] Hanbook of Engineering Tool & Alloy Steel Manual. [3] [12] Design Data Handbook by K.Mahadevan & K.Balaveera Reddy Adan,Calik.Effect of Cooling rate on Hardness and Microstructure of AISI 1020,AISI 1040 and AISI 1060 Steels. 219 ELK Asia Pacific Journals – Special Issue 36. CONDITION BASED PREDICTIVE MAINTENANCE ONBOARD NAVAL SHIPS S Jaison Department of Production College of Engineering Pune, India
[email protected] Karajagikar Jayant Department of Production College of Engineering Pune, India Abstract—Condition Based Predictive Maintenance (CBPM) is an effective tool in monitoring the heartbeats of a machinery. CBPM is an advanced tool in predicting the behavioral patterns of machinery components. The concept of unique natural frequency pertaining to individual components of machinery and their baseline signature monitoring can enable in analyzing the performance characteristics of machinery. In this modern era keeping pace with leap in technologies can yield wonders in upkeep of modern machinery, reduce maintenance costs and layoff time. A simple vibration baseline signature is all that is required to monitor machinery. Indian Naval ships unlike merchant ships consist of complex machinery and are subjected to rigorous exploitation pattern owing to war deployments. This results in early wear and tear of machinery. CBPM and its faithful implementation onboard ships can redefine the endurance characteristics of machinery, enable enhanced exploitation, thereby improve sustainability in war patrol. CBPM strategy can be utilized in systematic monitoring of equipment fitted onboard ships and enable implementation of E-maintenance strategy. Keywords—CBPM; Vibration; Oil Analysis; EMaintenance; Ships II. INTRODUCTION Condition Based Predictive Maintenance [3] can be used to schedule maintenance activity in a timely manner by ships and also prevent Proc. Of the Int. Conf: ARIMPIE-2015 unexpected equipment failures. The key is "the right information in the right time". By knowing which equipment needs maintenance, maintenance work can be better planned (spare parts, people, etc.) and what would have been "unplanned stops" are transformed to shorter and fewer "planned stops", thus increasing equipment availability. A systematic monitoring and recording of CBPM tools used for equipment can improve sustainability at high seas, thereby improving the fighting efficacy of a warship. a. History Human brain is an inbuilt sensory device with the ability for sense of touch and hearing. When the brain is trained to a situation, the sensory organs aide in fault identification when there is deviation from the original situation. In the past efficient machine operators significantly contributed to identify problems with feel of touch or by using a simple screwdriver to conduct sound from the bearing house to ears. However vibration equipment is required to obtain consistent results and maintain records. The origins of industrial vibration measurement can be attributed to TC Rathbone, Chief Engineer, Turbine & Machinery Division, New York division. Rathbone is credited with defining the initial guidelines for judging machine condition from vibration measurement in his paper ‘Vibration Tolerance’ published in 1939.The first vibration meters were introduced in 1950s and measured overall vibration either in peak to peak mils (thousandths of an inch) of vibratory displacement or in Inches Per Second (IPS). In the 1970s with personal computers in use the advent of digital signal processing led to FFT analyzers. In the 1980s with use of microprocessors on a single silicon chips [1] led to portable digital signal analyzers. From a simple overall amplitude measurement seventy years ago to the complex dynamic signatures utilized today for a detailed analysis of condition assessment have become an essential element for the safe operation and effectiveness of today’s modern machinery systems. b. CBPM Methods: To evaluate equipment condition, predictive maintenance utilizes nondestructive 220 ELK Asia Pacific Journals – Special Issue testing technologies such as infrared, acoustic (partial discharge and airborne ultrasonic), vibration analysis, sound level measurements, oil analysis, etc. These methods have been proven to be successful in predicting the condition of the equipment and decide on further exploitation accordingly. III. VIBRATION MONITORING Vibration measurement [4] used in monitoring a machinery is akin to the ECG used in medical field. It can be defined as the pulse of an machine. Irregularities can cause failures and can be effectively used as an early indicator or symptom for an defect. Vibration monitoring first begins with acquiring an accurate timevarying signal from a vibration transducer, such as an accelerometer. The raw analog signal is typically brought into a portable, digital instrument that processes it for a variety of user functions. Depending on user requirements for analysis and the native units of the raw signal, it can either be processed directly or routed to mathematical integrators for conversion to other units of vibration measurement. a. Narrowband analysis Narrowband analysis [7] is basically the analysis of FFT spectrum in a close band of frequencies (i.e. the frequency range in which our interest lies). Key element of this analysis is to determine the vibration frequencies present and how these vibration frequencies relate to the rotating speed (rpm) of the various machine components. To do this we require a vibration frequency analyser. Since from narrowband analysis we can determine the component level vibration, we can understand the health of machinery better. A narrowband spectrum analysis requires detailed knowledge of design/ construction of the equipment, its past history, operating conditions and list of potential components prone to damage/ failure. In addition, deviation from laid down operating instructions results in excessive operational stresses which changes the balance condition/ component alignment causing high dynamic loads which may eventually lead to accelerated wear. Such defects will invariable result in change in vibration trends of the machine. Proc. Of the Int. Conf: ARIMPIE-2015 Therefore, periodic vibration measurements as well analysis of change in vibration characteristics is critical to early identification of incipient faults as well as uncover the inaccurate operation practices. b. Signal Analysis This is a method of taking a real world, time-varying signal [5] and splitting it into components, each with an amplitude, a phase, and a frequency. By associating the frequencies with machine characteristics, and looking at the amplitudes, it is possible to pinpoint troubles very accurately. IV. CASE STUDY a. Vibration Trend Air-conditioning is the control of temperature, humidity, air purity and air movement within a space or group of spaces. It is a prime requirement in all Naval platforms to ensure that the ship's staff continue to operate at high levels of effectiveness and efficiency for long periods and the environment for essential equipment always remains satisfactory for reliable operation. This environmental control has to be achieved throughout the full spectrum of ambient conditions for which the ship is to be designed. Therefore, operational availability of all AC plants onboard Naval platforms is a mission critical requirement. One of the AC plants onboard a ship encountered extended operational requirements which were optimised by timely predictive evaluations and progressive corrective actions. i. Running hour extension: The ship had an operational requirement of extension of running hours on Air-Conditioning No. 3. Accordingly, running hours extension [8] (for 1000hrs on 10000hrlyroutine) trials were undertaken. The overall vibration levels recorded were satisfactory with max overall vibration of 10.5 mm/sec against the limit of 18 mm/sec. While all vibration and performance evaluation parameters were within acceptable 221 ELK Asia Pacific Journals – Special Issue Proc. Of the Int. Conf: ARIMPIE-2015 limits, an increasing trend was noticed at 1X and 2X of fundamental running frequency during Narrow Band analysis. The increasing trend was likely as the equipment was due for major overhaul as per Planned Preventive Maintenance program. The ship was advised to exploit the AC plant under more frequent monitoring of vibration/ performance parameters [9] with following observations:1. Presence of high amplitude peaks at 1X in vertical as compared to horizontal at compressor drive end indicative of increased bearing clearances 2. Increasing trend in amplitudes at 1X and 2X in all directions indicative of incipient weakness in pedestal structure which has been observed in past cases of weak pump stools/ base structures as shown in Table I. Measuring V A Direction 10.3 Comp free end Comp drive end 20.1 13.5 Motor drive end 7.8 Motor free end vertical direction 1. Presence of high amplitude peaks at 1X frequency in vertical (Fig. 2. ) as compared to horizontal direction indicating increased bearing clearances. 2. Presence of peaks at 2X in all directions indicating misalignment and weakness of pedestal structure (Fig .3. below shows a few spectrums) H 4.8 6.9 6.9 6.6 11.9 10.8 16.8 16.3 TABLE I. Overall vibrations (mm/sec) recorded ii. Considering the past trend, previous observations made during running hours extension trials and narrowband analysis, the following observations were made. Fig. 2. High amplitude peak at fundamental frequency in Fig. 3. Spectrums 3. Phase analysis revealed 90o phase difference between vertical to horizontal at motor drive end bearing indicative of unbalance of motor rotor. iii. Recommendations: The following recommendations were made 1. Overhaul of compressor 2. Balancing of motor shaft with pulley along with trueness checks of both pulleys 3. Survey/ repair of foundation structure 4. Renewal of mounts iv. Repair Actions:10000 hrly (MOH) of AC Plant along with 222 ELK Asia Pacific Journals – Special Issue renewal of SV mounts post testing / grouping and trueness checks of compressor & motor pulleys were carried out. Recorded overall vibrations within alarm limits post aforesaid repair actions. However, survey/ repair of foundation structure was not carried out by repair yard view requirement of three weeks of maintenance period involving lifting of AC and extensive de-gutting/ regutting. It was recommended to exploit the AC plant under observation and offer for narrowband analysis trials based on any increase in overall vibrations. v. Trials Post MOH: An increasing trend of vibrations at compressor free end in vertical direction was noticed post 77 hrs of exploitation (running hrs since MOH). Attenuation across six out of eight new mounts was found to be unsat. Poor attenuation across new mounts with higher overall vibrations recorded below mounts as compared to readings above mounts at three locations substantiated indications of weakness of pedestal structure. Overall vibrations recorded were shown in Table II. Vibration Monitori INITIAL Post MOH ng Points (Trials) &Renewal of Mounts V A H V A H Compressor 10.3 4.8 11.9 13.9 3.6 0.2 FE Compressor 5.2 5.1 8.1 20.1 6.9 10.8 DE Motor DE 13.5 6.9 16.8 7.9 6.0 6.3 Motor FE 7.8 6.6 16.3 7.7 5.3 9.6 TABLE II. Overall vibrations (mm/sec) recorded Narrowband analysis once again revealed high vibrations at 1X and 2X in almost all directions confirming weakness of pedestal (Fig .4 shows one such spectrum ).Therefore, firm recommendations for renewal/ Proc. Of the Int. Conf: ARIMPIE-2015 strengthening of base frame / foundation were made. Fig. 4. Spectrum depicting high 1X and 2X amplitudes vi. Final Trials: The survey of foundation post lifting of AC Compressor revealed corrosion/ weakness on 05 vertical foundation stiffeners and 02 horizontal baseframes. Overall vibrations recorded by ship post renewal of corroded vertical stiffeners and horizontal baseframes are as tabulated below as in Table III. Measuring V A H Direction 7.9 1.9 8.2 Comp free end 7.1 4.0 8.3 Comp drive end 7.4 3.4 6.7 Motor drive end 10.2 2.8 10.0 Motor free end TABLE III. Vibrations (mm/sec) post Repair of Foundation 7) Weakness of Base frame/ Structure: In general, the first indication of mechanical looseness related to weakness of structures has been found to be increased peaks at 2X fundamental frequency. The presence of both 1X and 2X of fundamental frequency in a balanced and aligned rotating machinery is most likely an 223 ELK Asia Pacific Journals – Special Issue indication of weakness of pedestal, distortion of base frame/ rocking motion. If the resulting looseness due to weakness of pedestal worsens, it will result in development of impulse/ impact events. In such a scenario, the FFT spectrum will show multiple harmonics. B) Oil Analysis Oil in machinery [6] is the lifeline and it runs though to provide lubrication, cooling as well as clear debris. Similar to a blood report undertaken on human beings to identify various suspensions for diagnosis and oil report can also diagnose the internal health of an machine. Wear particle concentrations (Fe, Pb & Sn) were observed in Spectrometric analysis report of HP Air Compressor (HPAC) (Sulzer) in advanced oil analysis returns of a ship. Thereafter, ship reported replacement/ flushing with new oil. However, wear particle concentrations were again observed in subsequent analysis. In both the reports abnormally high Sn concentration was a cause of concern. In the absence of an approved promulgated alarm/ alert values, trending and comparative analysis was undertaken for severity assessment. The analysis details of wear particle concentration (ppm) as given in Table in IV. TABLE IV. Comparative assessment of wear particle concentration Metal Same Compressors on P-17 class Proc. Of the Int. Conf: ARIMPIE-2015 Metal Probable sources Fe Gears, rolling bearings, cylinder liners, shafts, rust formation Pb A soft metal used for sacrificial wear surfaces such as journal bearings, Lead based babbits are widely used, Journal bearings grease, roller Bearings and bushings Sn Bronze bushes, washers and gears, rolling element bearings: alloyed element in cages, journal bearings: journal bearing pads (babbited) 1) Recommendations: In view of the above, the increased presence of Iron (Fe) along with Lead (Pb) and Tin (Sn) was indicative of white metal bearing wear. The scrutiny of Maintops of HPAC (Sulzer) revealed requirement of weardown checks of Main/ Con rod bearings as part of annual routine. It was confirmed from ship that the annual routine was overdue. Accordingly, OEM was also approached for investigation of increased wear particle concentration. Annual routines on HPAC no. 1 were carried out and investigations revealed wearing of crankshaft due to insufficient lubrication of main bearing. The early detection saved the crankshaft failure and seizure of engine. V. CBPM ONBOARD NAVAL SHIPS HPAC No 1 (Sulzer) 19 Aug 14 03 Oct 13 Fe 51.31 39.36 Pb 18.62 2.90 Sn 49.18 37.30 In addition to the OEM specifications, the probable sources of wear metals in lub-oil are shown in Table V. TABLE V. Probable sources of wear metals in Lubricating Oil A) Proposed Methodology for Naval ships The procedure of condition monitoring [9] involves trending, which examines the rate at which condition indicating parameters change with operating time. Therefore, it is a continuous process requiring persistent watch. The three circumstances which are to be considered while evaluating the ‘trends’ and the recommended actions to be taken by ships are shown in Fig .5. 224 ELK Asia Pacific Journals – Special Issue Case I Compare magnitude vis-à-vis alarm levels and if it exceeds alarm level / very close to alarm level Case II Proc. Of the Int. Conf: ARIMPIE-2015 Case III Magnitude within alarm level but there is an increasing trend with almost linear rate of increase Magnitude within alarm level but there is an abnormal increase compared to past reading The alarm limits promulgated for engineering equipment under the ambit of CBPM will fall in the Zone C. Carryout preliminary ‘change analysis’ Schedule more frequent monitoring and keep the equipment Fig .5 Analysis of parameters and under recommended actions observation. B) Vibration severity zones The vibration severity zones can be broadly considered as follows as shown in Fig.6 . Conduct trials Schedule more frequent monitoring 1) Zone A: Vibrations commissioned machine Fig .6 .Vibration Severity Zones of newly 2) Zone B (Normal Range): Vibrations are acceptable for unrestricted long-term operation 3) Zone C (Alarm Range): Vibrations considered unsatisfactory for long-term continuous operation 4)Zone D: Vibrations may cause damage to the machinery This requires analysis and corrective actions to be taken in the case of CBPM tool (vibration) levels crossing over to the alarm zone. V. E-MAINTENANCE ORIENTED STRATEGY ONBOARD NAVAL SHIPS E-Maintenance [9] is the need of the hour to bring all ships under a single ambit for effective monitoring. This will enable monitoring thousands of equipment fitted onboard hundreds of ships with the click of a button. This can be enabled by capturing baseline signatures of all equipment and categorizing them as per class of ships. CBPM techniques can enable implementation of E-Maintenance in a desired way. A suitable software should be developed to incorporate the details of equipment and just clicking on a particular equipment will give all the maintenance activities carried out and also indicate ships fitted with same equipment. Computerized maintenance management systems [2] on ships usually process data related to the maintenance operations, entered manually by the appropriate staff. 225 ELK Asia Pacific Journals – Special Issue Based on the given information about the faults or failures characteristics, measurement results, corrective and preventive actions taken, etc., the Trial teams plan appropriate maintenance strategy, generates work orders and allocate resources as shown in figure 7. The maintenance activity onboard a naval ship can be undertaken by developing suitable software to integrate the measurements undertaken on a mechanical component with electronic equipments. The maintenance of equipment fitted onboard hundreds of ship with each ship accounting for 200 machineries is an humongous task. It also amounts to huge amount of expenditure to the exchequer, extended layoff and elaborative trials. The aim of Emaintenance is to rely on CBPM tools, Delay maintenance based on reports generated, Reduce layoffs and monitoring of all equipment with click of a button. Proc. Of the Int. Conf: ARIMPIE-2015 A) If there is no significant change in magnitude from previous recording, no action required and periodic (monthly) recordings to be continued. B) If the vibration is increasing at a linear rate, more frequent monitoring should be scheduled and implemented by operators/ maintainers. A preliminary analysis of other performance parameters trend, lubrication condition, and tightness of bolts etc. need to be undertaken. C) If rate of change increases suddenly by approximately 25% or more as compared to previous reading then first line maintenance and increased frequency of monitoring must be prioritized. In case, the problem persists, narrowband analysis requirement to be raised. It is clearly seen from the above two case studies that the Vibration monitoring and Oil analysis based CBPM tools have been effectively utilized in timely and periodic evaluations of a critical operational machinery onboard Naval platform. This systematic approach enables generation of actionable data to schedule both preventive and corrective maintenance tasks effectively and help in easy maintenance. This can lead to development of E-maintenance strategy where in the equipment fitted onboard ships can be monitored effectively through the databases created using CBPM methodology. Fig .7 .E-Maintenance Strategy onboard ships VI. REFERENCES VI. CONCLUSION The purpose of periodic returns is to establish a trend and analyze the trending data to preempt/ predict incipient failure. An early detection of defect enables timely and easier corrective actions and preventing catastrophic failures/ downtime. Therefore, the following guidelines have been proposed for equipment vibration magnitudes in the ‘normal zone/ within alarm limit’. [1] Jasmin Celic, Aleksandar Cuculie,“ eMaintenance for ship electrical propulsion plants,” 36th International Convention on Information & Communication Technology Electronics & Microelectronics (MIPRO), 2013 , Opatija ;May 20-24, 2013; pp.12021205. 226 ELK Asia Pacific Journals – Special Issue [2] Mahalungkar, S. Ingram, M,“Online and manual (offline) vibration monitoring of equipment for reliability centered maintenance,” Cement Industry Technical Conference ; 25-30 April 2004;pp. 245-261. [3] Gary G .Yen , Kuo Chung Lin ,”Conditional Health Moniotring Using Vibration Signals” Proceedings of the 38th IEEE Conference on Decision and Control, ;Phoenix,AZ;7-10 Dec 1999;pp. 4493-4498. [4] Laggan, P.A. , “Vibration Monitoring “IEE Colloquium on Understanding your Condition Monitoring ;Chester;April 1999,pp. 301-311. [5] Agrawal, K.K, Pandey, G.N ,Chandrasekaran, K, “Analysis of the Condition Based Monitoring System for Heavy Industrial Machineries” IEEE International Conference on Computational Proc. Of the Int. Conf: ARIMPIE-2015 Intelligence and Computing Research (ICCIC);Enathi;26-28 Dec 2013;pp. 1-4. [6] Gao Jingwei;Zhang Peilin;Liu Baoyuan;Xie Zhengjun ,”An Integrated Fault Diagnosis Method of Gearboxes Using Oil Analysis and Vibration Analysis ” 8th International Conference on Electronic Measurement and Instruments(ICEMI ); Xi’an ;Aug 2007;pp. 371-374. [7] Jianjun Shi; Chunping Wu; Jianping Zhang; Jinlong Dou, “Monitoring and analysis of vibration caused by demolishing of a chimney with height of 150 meters “ International Conference on Remote Sensing, Environment and Transportation Engineering (RSETE); Nanjing; 24-26 June 2011 ; pp. 5095-5098. [8] Journal of Marine Engineering. [9] Manuals and journals on Navalships available in public domain 227