Memorial UniversityEN8000 Faculty of Engineering NavCad Tutorial !"#$%&'(&)'*+%*+,& !"#$%&'(&)'*+%*+, -----------------------------------------------------------------------------------------------------------------------------------.& /*+0'123+4'*---------------------------------------------------------------------------------------------------------------------------------------------.& 56%064%7&'(&8"6)"1 ------------------------------------------------------------------------------------------------------------------------------.& 9%,4,+"*3%&:0%143+4'*, -------------------------------------------------------------------------------------------------------------------------;& !"#$%&"'"&"()"*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ,! -(#"&$!./0$12#2 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3! %"&'4&52()"$62&"$7899$:"*/*#2()"$-*#/52#"+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ;! <(29=>/(?$#."$:"*89#*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ @! 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A*/(?$B8*#45$12#2++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ C! <DD/#/4(29$:"*/*#2()"$B4504("(#*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ C! :0'<2$,4'*&:0%143+4'*, --------------------------------------------------------------------------------------------------------------------- .=& -(#"&/(?$%&4089*/4($12#2 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++EF! %"&'4&5$%&4089*/4($%&"D/)#/4(++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++E,! !/>/(?$#."$%&40"99"&+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++E3! -*+.'/01+2'*& This tutorial is a basic introduction to NavCad. It introduces the basic aspects of the NavCad interface by walking through a sample analysis. The vessel used for the analysis is the fishing boat Marauder, model M455A. This vessel is the same as that used in the EN5011 resistance lab. The following table shows the general particulars of the vessel. The remainder of the information required for this tutorial has been scale of the lines plane below. LOA 2.873 m LBP 2.808 m B (at waterline) 0.943 m CB 0.322 CP 0.675 CWP 0.76 Loaded displacement T 0.425 m S 3.038 m2 34%.42%5&'(&6"4)"/& NavCad is a program for performing resistance and propulsion predictions. NavCad is based on a collection of empirical methods, both published and created by HydroComp. While working through a resistance and propulsion prediction, it will be necessary to select which method to use for the prediction. The accuracy of the results depends on the 1 of 13 %/21+2'*.& !"#$%&"'"&"()"*$ Once NavCad is opened. Simply hiting the SI button will set all the units to the default SI units. This can be changed to meters per seconds by selecting mps under the dropdown box. it is important to understand the prediction methods being used. as this will dictate the accuracy of the results. The convert button will change any values previously entered into NavCad to the new system of units. For this tutorial however.2.+"*1%&8. A dialog box will appear allowing the user to change the system of units and the precision of each value. Note that speed has been set to knots. the preferences should be changed by selecting the Edit ! Options menu. In short. 2 of 13 . we will use knots. Select OK to close the dialog box. 7%.Memorial University EN8000 Faculty of Engineering NavCad Tutorial prediction method used and how well your vessel fits into the category selected. Prediction methods exist that cover broad ranges of the vessels (such as all displacement vessels) as well as more specific vessels such as only Series 60 hulls. This will show a dialog box where general information related to the project is to be entered. Finally. Second.Memorial University EN8000 +(#"&$!. select Edit ! Conditions on menu bar.$/0#0$ The ship data needs to be entered before performing an analysis. we will use salt water and speeds ranging from 1 to 10 knots as shown below. To enter the required data. the density and viscosity of water must be entered. enter a description of the project as shown below. For this tutorial. the speeds at which NavCad should perform the analysis must be entered.-. First. Faculty of Engineering NavCad Tutorial 3 of 13 . These can be automatically entered by NavCad by selecting either Std salt for salt water or Std Fresh for fresh water. Additionally. Under this section. select the Hull button at the top of the dialog box. Once all the values have been entered as below. hitting the ! button next to Wetted Surface will give a list of methods for calculating the wetted surface area along with the results of each method. For this tutorial. Detailed descriptions of what each of the values represents can be accessed using the Help button. This page can be also be accessed from the menu bar by selecting Edit ! Hull. the Holtrop method has been used to approximate the value. values with a ! button (approximate sign) can be estimated by NavCad. hit the Done button. enter the information about the hull as shown below.Memorial University EN8000 Faculty of Engineering NavCad Tutorial Once the general data has been entered. The longitudinal center of buoyancy has been estimated as 2% aft of the mid-Lwl and the half entry angle has been estimated using Holtrop method. ratios and coefficients (such as the block coefficient) will be updated automatically. For example. Note that as values are entered. 4 of 13 . Under the section labeled Bare-Hull change the drop-down box to Calc. Selecting the button. will show the list of resistance methods available in NavCad.Memorial University EN8000 Faculty of Engineering NavCad Tutorial %"&'1&20()"$30&"$4566$7"*-*#0()"$+*#-20#"$ Once the hull information has been entered. This will cause NavCad to calculate the bare hull resistance. NavCad is now ready to predict the bare hull resistance. Next. The user must select an appropriate resistance method. NavCad sorts the list according to applicability for ease of use. The word Limit will be shown next to any values that fall outside of the suggested ranges. the range of applicable values will be displayed. the calculation method must be selected. For this tutorial we will select Holtrop 1984 as it is a well-known method. The details of the resistance analysis are contained in the left hand window pane. 5 of 13 . Once a method is highlighted. Roughness. the values have been estimated using Holtrop 3-D. The other three factors that are requied for the analysis are the Correlation allowance. 6 of 13 . the options must be selected. NavCad automatically calculates the resistance and plots the results.Memorial University EN8000 Faculty of Engineering NavCad Tutorial Once the prediction method is selected. Other options are for incorporating additional data such as model test or full-scale data into the analysis. The technique used should be prediction to tell NavCad that we want to predict the bare hull resistance. The Friction Line is the method used to compute the viscous resistance component. Each of these values can be entered manually or predicted by NavCad by using the ! buttons. Once the analysis has been configured. it can be ran by selecting the Calculate Resistance Analysis button on the toolbar (see below). Select ITTC to use the ITTC-57 ship-model correlation line. Newship and Holtrop respectively. For this example. and 3D form factor. Both the dependent and independent axis can be changed.$#. then click OK. This displays the table of results calculated by NavCad.Memorial University EN8000 8(069:-(. To change the plot data. Faculty of Engineering NavCad Tutorial 7 of 13 ."+"& The results can be viewed by clicking the + button in the top right corner of the screen. select Tools ! Edit Graph Data from the menu bar. Select Fn for the X-axis and Rtotal for the Y-axis."$7"*56#*$ 8$'++2*9&+:%&. The graph will change to plot the total resistance against the Froude Number. 2+242+>&?*"$>. 8 of 13 . Hit OK when finished.& To perform a sensitivity analysis. we must be edit results mode. Click the Edit Results Mode button on the menu bar to toggle in and out of edit results mode.Memorial University EN8000 Faculty of Engineering NavCad Tutorial 8%.2. Click the Show Sensitivity Analysis button.<2*9&"&=%*. A dialog box will appear which shows the percent change by changing each of the parameters by 1%. a new toolbar will appear under the data table. In edit results mode.('. enter the significant wave height and modal wave period under the seas data.Memorial University EN8000 <*-(. First we must enter the wave data that the ship will be operating in. under Added Drag. it may be desirable to use your own data (for example from a model test). additional resistance components can be estimated such as appendage drag. In this tutorial we will estimate the effect of waves on the resistance of the fishing boat. This information can be selected based on the sea state by using the ! buttons. On the left hand window pane. use the Calculate Resistance Analysis button to compute the added resistance in waves and add it to the bare-hull resistance. Under this menu. Select Edit ! Environment from the menu bar.$=5*#12$/0#0$ For additional stages of the analysis. the Modified Aertssen method has been used to compute the values used in this tutorial. Next. To enter your own data. you need to be in edit results mode.1("(#*$ Outside of the bare hull resistance. Hit Done when finished. wind drag. We do this by selecting Off under the drop down menu for Bare-Hull. Enter your own lab data into the Rbare column of the table. Your own data can now be entered directly into the table. and added resistance due to waves and channel effects. Next use the icon to select the prediction method. Finally. select Calc next under Seas. Faculty of Engineering NavCad Tutorial 8>>-#-1(06$7"*-*#0()"$=12. we must inform NavCad that we have entered our own Bare Hull resistance values so that it does not over-write them with predicted values. the method of calculating the resistance needs to be selected. Before computing the resistance values. 9 of 13 . & +(#"&-(. This is entered in the form of an engine file.'@0$. Once the data has been entered. This information should be entered (see below). fuel consumption rates can be entered to obtain predictions on the fuel consumption rates.$%&1. To create an engine file select Library ! Engine. Different engines will be capable of delivering different powers at different shaft speeds. In order to perform a propulsion analysis. select Use Now and the engine file. 10 of 13 . For this tutorial. select to the propulsion mode by selecting View! Propulsion Mode. NavCad requires information about the prime mover being used. Additional.2'*&8.56*-1($/0#0$ To begin the propulsion predictions.%/21+2'*. The following dialog box will appear.Memorial University EN8000 Faculty of Engineering NavCad Tutorial 8. we will only use the power versus shaft speed curve. Select Done when finished. Note that the Engine file saved previously has already been selected. 11 of 13 . we will be using a standard B-Series propeller.Memorial University EN8000 Faculty of Engineering NavCad Tutorial Next. Do this by selecting Edit ! Propulsor from the menu bar. The propeller data is entered in the same manner as the resistance data. For this tutorial. enter the information about the propulsor. Enter the information below. Memorial University EN8000 Faculty of Engineering NavCad Tutorial %"&'1&2$%&1. remember to select off so that the values are not overwritten. In this tutorial. Perform the analysis by clicking the Calculate propulsion analysis that has replaced the calculate resistance analysis used in resistance mode. and relative rotative efficiency based on empirical formulas or can be entered by the user. NavCad can predict the wake fraction. we will use NavCad to estimate all of these factors using empirical formulas for a Simple towboat.56*-1($%&">-)#-1($ Similar to the resistance prediction. To enter the values yourself. thrust deduction. the results can be viewed and manipulated in the same way as the resistance results. Select the icon next to each factor and select Simple towboat. Also. go to edit results mode and enter the data in the table. Once computed. Under Analysis type select Free run to predict the propulsion performance under normal conditions. Other types of analysis can handle situations such as towing operations. 12 of 13 . the details of the prediction must be entered on the left hand side. "66"&$ The previous results are for an arbitrary propeller geometry. Faculty of Engineering NavCad Tutorial 13 of 13 . NavCad has a built in propeller selection routine. In this example. We will therefore select Keep next to diameter and select Size next to the remaining properties. a given amount of power is used. We will therefore select Shaft Power under the Size for drop down box."$%&1. select Edit ! Propulsor from the menu bar. Click OK and then rerun the analysis to obtain results for the propeller selected.$#. As an alternative. then click Size.Memorial University EN8000 !-:-(. To access the routine. The goal is to have NavCad to select a propeller such that at the design speed. we could also select the amount of thrust that is desired at a given speed. This option is suitable to work boats that required a certain amount of towing force. Enter the data shown in the following figure. click the button labeled Propulsion sizing. we will assume that we have selected the largest propeller diameter possible. NavCad will select a propeller and gear ratio that consumes the required power at the design speed and minimizes the amount of cavitation. Under the dialog box.