Version 15.01.2009 PACKAGE CONTENTS In addition to the manual there is either normally a CD-Rom supplied with this package. New users will be provided with a hardware key or Dongle for software protection. Version updates are available for download from the Wolfson Unit web site at www.wumtia.com on the Software page Customer Download Area. PROTECTION SYSTEM Single user option This program utilises a hardware key or DONGLE which fits into either the Printer or USB port of the computer, if using a printer port type, the printer lead then plugs into the back of the key. The individual programs check for the presence of this key. If it is not found, a warning is given, place the DONGLE in the port before continuing. Network option The network option is a version that provides network license protection using just one key. The network option works with TCP/IP networks. One computer on the network is designated the security server and will have the dongle connected to it. The server software VSSERVER is also installed on this computer. The VSSERVER is a windows application that should be installed on the machine designated as the security server. This machine does not have to be an actual network server but it must be running Windows 95, 98, ME, NT, 2000 or XP, have at least one parallel or USB port and be available for access by client machines. Run the VSSERVER Installation from the server directory. The required device drivers are automatically installed. Connect the hardware dongle key to the parallel or USB port and start the server by selecting it from the Start menu. The first time the server is run the server will attempt to start for a few seconds and then fail because it has not yet been setup. Click the Setup button and enter the server name or IP address, leave the port as 6666 and click Apply and Close. Now click the ‘Retry to start server button’ which should successfully start the server. Don’t worry about the message ‘IP Security not loaded’ as this can be set up later if required. You can now click OK to place the Security server in the system tray. You can at any time double click the Security Server icon either to change the settings or to view the current status. The hardware drivers are also required by your client computers to enable communication with the security server. On each server computer run the driver install program Sl2inst.exe on the disk provided. Click the ‘Install’ button to copy the appropriate device driver file for the operating system and add the registry entries. Click the ‘Uninstall’ button to remove the drivers. A command line version drvinst.exe can also be found in the install folder. Type ‘drvinst install’ to install and ‘drvinst uninstall’ to remove the drivers. If you move either of these programs to a different directory ensure to copy both of the driver files ‘windrvr.vxd’ and ‘windrvr.sys’ and also ‘wdrvr.dll’ to the same directory. On each client computer the port and IP address of the license server needs to be set. Nsl2set.exe is a windows program that can be used to set the server address and port. setnet.exe is a windows command line version of nsl2set.exe. Type ‘setnet.exe address port’ where address is the server name or IP address and port (optional) is the port required (defaults to 6666 if not entered). i CONTENTS Page No CONFIGURING THE SYSTEM .............................................................................. 1 INTRODUCTION .................................................................................................... 1 PROCESS DESCRIPTION ...................................................................................... 2 GETTING STARTED ............................................................................................. 5 PROGRAM REFERENCE ..................................................................................... 10 General controls ........................................................................................ 10 Display pages ........................................................................................... 12 Dialog boxes ............................................................................................. 15 Menus....................................................................................................... 17 Toolbar ..................................................................................................... 24 POWER PREDICTION GUIDE ............................................................................. 25 GLOSSARY........................................................................................................... 49 ERROR MESSAGES ............................................................................................. 52 APPENDIX I APPENDIX II References ........................................................................... 53 File Formats.......................................................................... 54 INDEX ................................................................................................................... 58 ii Power Prediction 1.0 CONFIGURING THE SYSTEM WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Configuration of the system is performed by a file on the program disc entitled SETUP.EXE. Before undertaking the configuration however, take a backup copy of the disc supplied, and then follow this procedure with the backup copy :A. B. C. Place the program disc in CD drive, or download the installation file. From the File Manager run SETUP. Follow the installation prompts. The sub-directory onto which the program will be installed defaults to C:\Program Files\Wolfson\Props, and the Windows group file defaults to Wolfson. These may be changed if required. The installation will automatically add a device driver required for correct operation of the protection system. Windows will need to be restarted in order for it to take effect. D. The program may then be run from the program manager as normal. 2.0 INTRODUCTION This manual describes a program enabling ship and small craft power predictions to be performed, using standard series data. It is assumed that the user has a basic knowledge of the machine and the operation of programs under Windows. The method used to calculate the resistance of the ship depends upon the type of vessel. Ship forms Merchant ships, single or twin screw Tugs & Trawlers BSRA methodical series High speed forms NPL round bilge Series 64 round bilge SSPA round bilge Davidson Regression, round bilge/chine Savitsky planing hulls Wolfson Unit hard chine Wolfson Unit round bilge Wolfson Unit catamaran Wolfson Unit high speed Sailing yacht forms Delft Series The program can calculate the effect of a wide range of appendages and the effect of systematic changes in up to ten hull form parameters. In addition to calculating the resistance and EHP, the program also calculates the propulsive coefficients for each speed. Each method has valid ranges, for speed, length/beam ratio etc. The parameters (e.g. Length) used to define the ship, vary between methods. 1 Mennen [Refs. If the Wolfson Unit’s GOPlot plotting program is available. Holtrop and G. The speeds over which the calculations are performed are then selected.16 . or left for later use when comparing other results against the base. The method was developed through a regression analysis of data from 93 models of tugs and trawlers obtained by the Netherlands Ship Model Basin. In addition to calculating the resistance and EHP. van Oortmerssen [Ref. Available methods of calculation: Single Screw Ships This analysis is based upon work published by J. this method also calculates the propulsive coefficients for each of the speeds. In addition to calculating the resistance and EHP.0. and included within the base data.45.1 . The Cases option creates secondary definitions of the vessel with alternative parameter data. comprising various of its parameters.16 .0 PROCESS DESCRIPTION WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS The program has a Base definition of a vessel.3].Power Prediction 3. The method was developed through a regression analysis of random model and full-scale data obtained by the Netherlands Ship Model Basin. Once the calculation is complete the results may be stored for future use.2. Once all the data have been entered they can be checked for validity and the calculations performed. this method also calculates the propulsive coefficients for each of the speeds. 1. It uses a wide range of hull parameters from which to calculate calm water resistance and Effective Horsepower of twin screw merchant ships in the Froude number range 0. Appendages can be defined. In addition to calculating the resistance and EHP.2. It uses a wide range of hull parameters from which to calculate calm water resistance and Effective Horsepower of single screw merchant ships in the Froude number range 0.0.45. shown on the screen as tables or graphs or sent to a printer. 2 .5. All the data relating to a ship can be loaded from or saved to disc. The method was developed through a regression analysis of random model and full-scale data obtained by the Netherlands Ship Model Basin.3]. Holtrop and G. 1. Mennen [Refs. this method also calculates the propulsive coefficients for each of the speeds.0. 4]. It uses a wide range of parameters from which to calculate calm water resistance and Effective Horsepower of tugs and trawler forms in the Froude number range 0. The general flow of program use is to create the basis ship and define any appendages and set up any cases required. data may also be sent to that in order to produce report style plots. Twin Screw Ships This analysis is based upon work published by J. Tugs and Trawlers Method This analysis is based upon work published by G. Power Prediction BSRA Method WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS This analysis is based upon work published by M. this method also calculates the propulsive coefficients for each of the speeds. Davidson Regression for Round Bilge and Planing Craft This analysis is based upon work published by J. This method was developed from a large database and consists of an interpolation of the residuary resistance of a vessel over a wide range of Froude numbers. for high speed round bilge hull forms in the Froude number range 0. Bailey [Ref. Parker [Ref. as a function of speed.22. Savitsky Planing Prediction This routine is based upon a computational procedure presented by D. this method also calculates the propulsive coefficients for each of the speeds.24. one of which was a hard chine form. 10]. 3 . It uses a wide range of hull parameters from which to calculate calm water resistance and Effective Horsepower in the Froude number range of 0. It uses a wide range of hull parameters from which to calculate calm water resistance and Effective Horsepower.1. 9].0. Sabit [Ref. The equation was derived from 7 model series tests. 5] and a regression analysis reported by A. LCB at rest and the ratio of immersed transom area to maximum section area. half angle of entry. Savitsky [Ref. The calculations are based upon hydrodynamic planing equations describing lift. Lindgren and A. for different length/displacement and length/beam ratios. Mercier and D. wetted length and porpoising stability. Series 64 This analysis is based upon work published by H. In addition to calculating the resistance and EHP. this method also calculates the propulsive coefficients for each of the speeds. The report presents a 14 term regression equation for specific resistance based on five hull parameters: length/displacement ratio. 7]. 6]. It considers a wide range of hull parameters from which to calculate calm water resistance and Effective Horsepower. An equilibrium trim condition is determined allowing the calculation of horsepower. 11].15 . The method was developed through an analysis of the BSRA Methodical Series data. centre of pressure and trim. The program incorporates an extra iteration loop to allow for reducing beam at high speeds. 8].24 . beam loading. SSPA Series This analysis is based upon work published by H. wetted area. In addition to calculating the resistance and EHP. drag. this method also calculates the propulsive coefficients for each of the speeds. NPL Round Bilge Craft This analysis is based upon work presented by D. Savitsky [Ref. this method also calculates the propulsive coefficients for each of the speeds. Yeh [Ref. from which is calculated the calm water resistance and Effective Horsepower. Williams [Ref. deadrise and loading. An ITTC 1957 frictional coefficient is calculated and the total resistance and Effective Horsepower computed. The regression calculates a comparative performance coefficient over a range of volume Froude numbers. Wolfson Unit Catamaran This series is a regression of 13 parametric variants of round bilge semi-displacement demi-hulled catamarans. Wolfson Unit Round Bilge This series is a regression of 30 round bilge models tested at the Wolfson Unit since 1968. or by trim tabs or wedges. 16]. and J. Keuning et al [Ref.0. The effects of varying wetted surface area with speed are automatically taken into account. The revised regression of [Ref. In order to allow for surface roughness. 13]. The regression is similar to the original hard chine methods. 16]. to which frictional resistance for an entered or calculated wetted area is added. a separate regression of wetted are against speed is made. In order to allow for surface roughness. unpublished.0. and hull spacing ratios. either by positioning the LCG. The model tests were performed on demi-hulls of the NPL round-bilge series. but the hulls have been chosen to allow calculations up to volume Froude numbers of 5. presented papers by J. up to 2.75.0. and described in Molland et al [Ref. by Robinson [Ref.Power Prediction Delft Systematic Yacht Hull Series WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS This series is a regression of 40 hull form variations of sailing yacht hulls. 4 . A. Wolfson Unit High Speed Hulls This series is a regression of 41 hard chine models tested at the Wolfson Unit since 1999. The data are all taken from test models which have been optimised for trim. a separate regression of wetted are against speed is made. for varying length-displacement. tested in the University of Southampton. and interference factors. The effects of varying wetted surface area with speed are automatically taken into account. which is then faired and used to obtain the vessel’s total resistance. length-beam. either by positioning the LCG. either by positioning the LCG. extended to high length-displacement and length-beam ratios. by Robinson [Ref. or by trim tabs or wedges. 12]. 13] is used in order to calculate the upright residuary resistance of a yacht canoe body. over a range of Froude numbers. up to 3. or by trim tabs or wedges. which is then faired and used to obtain the vessel’s total resistance. The regression calculates the residuary resistance. Gerritsma et al [Ref. which is then faired and used to obtain the vessel’s total resistance. bulbs and rudders can be added via the standard appendage options. The effects of keels. a separate regression of wetted are against speed is made. The effects of varying wetted surface area with speed are automatically taken into account. Wolfson Unit Chine Craft This series is a regression of 66 hard chine models tested at the Wolfson Unit since 1968. In order to allow for surface roughness. 14]. up to 1. The data are all taken from test models which have been optimised for trim. The regression calculates a comparative performance coefficient over a range of volume Froude numbers. The data are all taken from test models which have been optimised for trim. editing information. changes the page: 1. which is split into five pages.0 4. Results page. showing its use. Toolbar . to fill the entire screen. Each icon displays a ‘hint’. The results of calculations may be copied to the report page. all of the items in the tabbed notebook area are rescaled. the selection of calculation method. 4. Cases page. a tabbed notebook and a status line: Menu . This page contains the main data concerning the vessel form. If the program’s display is maximised.quick commands Tabbed area notebook - data Status line . and obtaining on-line help. and the speed range. The Toolbar contains icons. and defined for inclusion in the calculation. occurs in the Tabbed Notebook area. Appendages page. The Status Line indicates the function of the various data fields in the notebook area when the mouse cursor is placed over them. 5 . 2. printing. which can then be edited and printed. This page allows multiple sets of calculations to be defined based upon variations of the hull and appendage characteristics. when the mouse cursor is placed over it. or selecting the page in the Window menu item. which carry out the more common commands such as loading in data. Report page. setting graphics options. This page contains the results of the most recently performed calculations. as well as the display of results. This page allows appendages to be selected from a list of available types. a menu.hints The Menu allows access to a variety of commands for loading and saving data to files. 5.Power Prediction 4. but dragging with the mouse may increase its boundaries. The main window may not be resized below its initial value. All of the data entry and editing. a toolbar. Hull page.1 WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS GETTING STARTED The main screen The screen is divided into four main areas. 3. Clicking the mouse on the titled tabs.commands etc. which displays the File Setup dialog. if present Navigate to a GoPlot file to be used as a template for the results Navigate to a folder for storing the temporary file created at each run Navigate to a JPEG file used as am optional logo in the HTML Report 4. Highlight the Length field and enter 20 then use the tab key to move through the required fields:Base Data Length Beam Displacement LCB Wetted area 20 5 20 -7 0 Coefficients Prop angle 10 Speed First Last Increment 10 20 1 6 . click on the appropriate Browse button.EXE file. select the Set up File links option. and enter the following values. The three fields are:Location of GOPlot Graphics Template Results file Report logo Navigate to the GOPLOT. This is especially important in terms of programs operating on network drives. and then: a) Set the Calculation method to type 5 (NPL Round Bilge Craft).2 Preparing file locations WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Before running calculations.Power Prediction 4. and also to specify where the temporary results file should be saved. where file permissions may not allow file saving.3 A simple calculation In this first example the most basic calculations are made for a vessel with no appendages. the program can be configured in order to operate with the Wolfson Unit GOPlot graphics program. To specify any of the three fields. From the File menu. Start the program. effective power. wake fraction. and then select Show graph. then click the report page tab and confirm that the results are displayed there. copied to the clipboard for inclusion in another document. The text shown may be edited. a) Click on the words Control Surface in the defined box and the properties of the appendage are displayed on the left-hand side of the screen. The program will perform a calculation and switch to the Results page:The calculated results will appear in the grid. Either click them once to highlight and click the << Add button. The appendage type is added to the list of defined appendages. or double click on the words Control Surface. or printed directly by choosing the File|Print option or clicking the Print icon in the toolbar 4. showing that the data are not within the legal range for the calculation method. The resistance. The available appendage types are shown in a list box on the right hand side of the screen. In this case. or use the right mouse button to display the pop-up menu. To view a graph of the effective power. Enter the values as shown::- 7 .Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS b) Click on the Calculate button. two rudders will be added to the definition. This is the most basic form of calculation. The program will display an error message. a) Click the Appendages tab on the main tabbed notebook. then either select the Edit option from the main menu. highlight a cell in the EHP column by clicking on it. Before continuing use the pop-up or Edit Menu and select Copy to Report.4 Adding an appendage The program allows the user to investigate the effect of appendages on the resistance. thrust deduction and rotative and hull efficiencies are calculated at each speed. c) Click the OK button and alter the displacement value to 50 and click the Calculate icon in the toolbar. The resistance at 20 knots should have increased from 46.13 kN to 47. The Case 1 Appendages field should display a 1. This is what the Cases option allows. or double click on the word Appendages in the Parameters list. c) Either select the Edit|Add Case option.04 kN. As a change to the vessel has occurred and new data not yet calculated the table of results is removed from the display. b) Move to the Cases page and either highlight the appendages parameter and use the Edit|Add Parameter menu option. rather than calculating the two results individually and comparing the results from one print out with another it is more convenient to calculate both conditions together and make a direct comparison on-screen. Click the On/Off box to select the rudders. then click OK. to create a new case for calculation and then double click the data field in the ‘Case 1’ row under the Appendages column. This ensures that the base calculation will not include an allowance for the rudders. or use the pop-up menu to select its Add Case. However. defined parameters may be varied and all of the resistance calculations performed together and compared with the Base value set up on the main Hull page. Click on the Calculate icon to display the revised calculation. or a combination of.Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Return to the Results page. and then turn off the Rudders definition by unchecking the On box. a) First move back to the Appendages page. 4. A dialog box will be displayed which lists the defined appendages and allows each to be set On or Off in the calculation. highlight the Control Surface in the defined appendages list.5 Comparing cases The two sets of data calculated so far show that small differences in the definition of the hull make a difference in the resistance. Any one. 8 . if the Wolfson Unit’s GOPlot program is available. From the Results Page Edit menu or pop-up menu.Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS d) The case is now set up. 4. 9 . the Base data and the Case 1 data. Return to the Results page and click the Calculate icon.7 Review the Report Finally. appendages.6 Send to GOPlot Once data are calculated. 4. To see the effect of the rudders view the graph by taking the Edit|Show graph option:Up to ten cases can be set up. or parametric variation in the base parameters. Switch between the two by clicking on the notebook tabs. These can be used to see the effect of roughness. This time two of the tabs in the output area will be available to view. Click on the tab to view this. data can be sent to it for creating a more versatile graph for presentation. an HTML formatted report listing the results of the last set of calculations can be viewed in the Report Page. allowing variation of any of the parameters used in the calculations. and select the cases required for sending via the clipboard:The program can launch GOPlot automatically by selecting the Launch GOPlot option prior to clicking on OK. select the Send to GOPlot option. with associated text.g.0 PROGRAM REFERENCE WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS The program operates by means of the normal Windows screen controls and menus as well as some special features. Scroll down the list and highlight the required value. Cases and Report. or press the appropriate hot-key option (the Alt key and underlined letter).Power Prediction 5. The notebook is split into four pages. containing a check mark.1 General controls Menus operate in the standard Windows way. A box on the screen which can contain a line of text. otherwise use the left and right arrow keys to move between items. Check box. Click on a menu item. clicking on the arrow opens up a drop down list of the text associated with each choice. each of which can contain other controls. 2. Appendages. A small box.e. A box on the screen which contains one of a number of choices. the left and right arrows can also be used to change pages. 10 . see below. highlighting it with the mouse. used to toggle an option on or off. located below the main menu line. the notebook itself has the program’s focus. Each toolbar icon displays a hint message if the pointer is left over it for a short while. 4. To change pages click the mouse button when the pointer is over one of the tabs. each containing its own set of controls. To the right of the box is a downward pointing arrow. Pressing the Alt key on its own toggles the program focus to/from the main menu line. i. e. When a drop down menu is displayed the up and down keys move through the list. Selection box. If the box has focus the option can also be changed using the arrow keys. 3. then click the mouse button. i. which contains the page name as an identifier. Edit box. Each page is identified by a tab. Hull. To operate a toolbar command click the mouse button when the pointer is located over the icon. shows the state of the option. The main area of the screen window is taken up by a Tabbed notebook. As a page is displayed the menu and toolbars change as necessary. and either a further drop down menu opens. An X or tick. The toolbar consists of various small icons. or by using the tab key until the content is highlighted. 5. or press the Enter key when the menu item is highlighted. Results. The text can be modified by giving the box the focus. If a tab is already highlighted. A screen control which displays multiple pages. Tabbed notebook. To change the option click the mouse button when the pointer is over the box. or the menu command is performed. The box. The list is removed and the box content changed to show the chosen item. Within each of the notebook pages the program uses a variety of controls: - 1.e. indicates that the option is selected. The Hull page contains the edit boxes used to enter and edit the various data values required for the calculation. List Box. There are also selection boxes for the calculation method. which are fixed. Parameters may be added to or removed from the list.g. which consists of a browser. e. and the scroll bars allow different parts of the memo to be displayed in the available space. To alter a value highlight the cell by pressing the mouse button with the pointer located over the cell position. appendage types. down. units. de-selected and edited.g. The Case page displays a table of the defined cases. Secondly. Browser. The program checks to see that the characters form a valid number before calculating. A matrix of strings drawn in a grid. If the number of strings is too large for the space provided. Browsers can contain many lines of text. and the values of the parameters to be used in their calculation. Buttons can also be operated with a hot-key sequence of the Alt key and their underlined letter. Each string occupies a cell in the grid. When there are no calculated values available the notebook is hidden. 6. they allow appendages to be added or removed from Standard types or from User Defined types. each with a string grid to contain a set of calculated resistance data. and data checks. 7. 8. Cells shown in grey are not available for editing and show headings. To press a button. The Appendage page and associated pop-up menu serve two purposes. The content can be printed or copied to the clipboard or other program. String grid. the up and down keys can move the selection to a different line. tables.Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS 5.g. Buttons are used to initiate specific commands. then a vertical scroll bar is shown within the box and can be moved with the mouse to scroll the box contents. The output from the program is stored on the Report page. Button. If the box has focus. e. or the old one edited. left or right keys to move the highlight to the required cell. The Results page is taken up by a further tabbed notebook containing eleven pages. and allows them to be selected.g. Firstly. or calculated values. e. Speed. If a cell is already highlighted use the up. Once the correct cell is highlighted the new value can be typed. Alternatively the Enter key will operate a button if the button has focus. with variable lengths. the Report Page. A browser is an area of the screen which can contain HTML formatted text. Following a successful calculation. List boxes. the notebook tabs that contain data are displayed with the case number. locate the pointer over the button and press the mouse button. if non numeric characters are found an error message is displayed and the program requests that the values is corrected. otherwise a line may be selected by placing the mouse pointer over it and pressing the button. and images. hold a set of text strings e. usually the button will form part of a tab sequence and will receive focus by repetitively pressing the tab key. and new cases created. The Appendages page displays the list of available and defined appendages. 11 . they allow User Defined types to be created from combinations of the Standard types. the Length. The hull roughness allowance. where the program checks that an individual parameter such as CB or L/B. and so can be used as a form factor term e. Boundary errors occur when the program finds that the input values set fall outside the boundaries of the calculation method. 0. Altering the selection in the Checking box can set the level of checking. where certain of the calculation methods are only applicable to combinations of parameter ranges which form an envelope of acceptable values.0 then it is used as an addition to the calculated skin friction coefficient (Cf). If checking is not strict then the program includes a warning message in the Report. 1. Input data are checked for validity before running a calculation.g. · Displacement The weight of the vessel. If the number entered is less than 1. · Units · Roughness · Vessel Data · · Base Data (Depending upon method) · Length The length (waterline or overall) of the vessel. including units. and envelope. · Draught The maximum draught of the vessel excluding appendages. This is split into three groups. · LCB The longitudinal centre of buoyancy as a percentage of the length. see the Design Guide. and on the Results page. · Wetted Area The wetted surface area at rest excluding appendages. Alternatively if a number greater that 1. For a full description of each item. either metric or imperial. Free only checks for the range. · Beam The beam (extreme or waterline) of the vessel.2 5. A selection box for choosing the calculation method. the contents of which alter depending upon which calculation method is employed.0004. Strict will only allow a calculation to proceed if both the range and envelope are valid. 12 . There are two types.1 Display pages Hull Page WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS The hull page is used to describe the vessel geometry and the calculation type to be used.2.1. None does no checking. range. lies within the allowable range of values.g. The required speed range is also set on this page. A selection box used to choose the units. A selection box for choosing the level of data checking. It contains the following elements: · Heading · Calculation method · Checking A general heading for the data used in the current file is entered in the heading edit box.0 is entered then this is used as a multiplication factor for Cf. e.Power Prediction 5. The methods and their description are detailed in the Power Prediction Guide. a tabbed notebook is displayed. The vessel’s trim. The half angle of entrance at the forward end of the waterline. The deadrise angle at the transom. The waterline coefficient The diameter of the vessel’s propellers. using the Edit menu. The longitudinal centre of flotation. The ratio of the area of the transom to the maximum section. If input values have been altered. The first speed for calculation.2 Results page Bulb Ht Bulb area Transom area Shape factor Half angle T/Amax The height of the centre of cross sectional area of the bulbous bow. The ratio of the propeller pitch to its diameter. A coefficient relating the shape of the vessel's afterbody. and new speeds can be added to the list. the tables cannot be viewed until another calculation is performed.2. The average deadrise angle of the vessel's planing surface. To view a case. or pop-up. The vertical centre of gravity. with the results of the base calculation and any valid cases. These data set the speed range required for calculation. The angle which the propeller line makes with the buttock line. The results displayed may be viewed as a graph. · Special · · · · · · · Speed · First · Last · Increment 5. expressed as a draught difference. The perpendicular distance from VCG to the propeller shaft line. The last speed for calculation.Power Prediction · Coefficients · · · · · · · · · · · · Cp Cw Prop Diam Pitch/diam BAR Trim Prop angle VCG Thrust arm Deadrise (Sav) Deadrise (Wolf) LCF WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS The prismatic coefficient. The propeller’s blade area ratio. click on the appropriate notebook tab. The increment between speeds The Results page holds the latest results of a calculation. 13 . The transverse cross sectional area of the vessel's bulbous bow. The area of the transom immersed when stationary. together with any calculated quantity such as wetted area. Once valid data are available for viewing. The available range of speeds is shown at the top of the page. or sent to the Report page. i. and new cases created.Power Prediction 5.e. The page is divided into three regions: On the right is a list of the Available Types. those currently associated with the hull.3 Appendages Page WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS The Appendages page displays the list of available and defined appendages. and a cylinder. and the values of the parameters to be used in their calculation. a further list box is displayed below the Appendages Defined box. Initially this list is empty. select the appropriate column and take the Delete parameter option in the Edit or pop-up menus. the boss. a special dialog box is displayed. they allow appendages to be added or removed from the definition.2. In the middle of the page is a list of the Appendages Defined.g. the strut. and allows them to be selected. User Defined appendages are combinations of standard types which. To add a new case take the Add Case option in the Edit or pop-up menus. which is defined by the calculation method. e. i. define a new appendage. If the parameter selected is the number of appendages. Firstly. 5. The Appendages page and associated pop-up menu serve two purposes. or highlight it and take the Add Parameter option in the Edit or Pop-Up menus. the standard and any user-defined appendage types. When one of the defined appendages is selected in the Appendages Defined list box.e. Parameters may be added to or removed from the list. To remove a case select the appropriate row in the table and take the Delete Case option from the Edit or Pop-Up menus. a set of edit boxes showing its parameters is displayed. The rest of the page is a taken up by a table of case conditions. Secondly. To add a parameter to the table either double click the parameter in the list. they allow User Defined types to be created from combinations of the Standard types. select the appropriate column and row and type a new value. that set on the Hull page. and values may be entered or edited as required. To edit the values of parameters in the case table. initially empty. The parameter values for the new case will be taken initially from the base vessel definition. At the bottom of these a check box is shown allowing the appendage to be automatically included in the calculations. i. when grouped together. 14 . a P Bracket can be defined as a combination of a control surface. allowing the defined appendages to be selected for inclusion in the calculation or ignored. The edit cases screen is divided into two regions: On the right is a list of the parameters required for defining the base vessel.e. de-selected and edited. To remove a parameter from the table.2. or left unused in the base calculation but available for use in the Cases. The left-hand portion of the screen is reserved for details of individual appendages. allowing selection of the individual parts of the appendage. When a User Defined appendage is selected.4 Cases Page The Case page displays a table of the defined cases. Click on the dialog to close it. appendage definition. The document can be printed. or copied from the report page to the clipboard for inclusion in other programs.3 5.6 Output Window The output window is a means of viewing and printing the results graphically.3.2.Power Prediction 5. created at each calculation. 15 . 5.4 Plot Options Dialog The Plot Options Dialog is used to set-up the way in which graph plots are presented on the Output Window. The output graph can be altered using the File|Plot Options command on the window’s menu bar and then printed or stored.3 About Dialog The About Dialog indicates the Power Prediction Program version.1 Dialog boxes Set File Links Dialog The dialog is used to locate the GOPlot program and a graphics template file. Check the required cases. These edit boxes set the maximum number of ticks along the x-axis and yaxis respectively.2 Send to GOPlot dialog This dialog allows the user to specify which calculated cases to send to GOPlot via the clipboard.3.2. and also to set the location for the temporary results file. if available. Optionally. The font button activates the standard Font Dialog. Sets the tick length on the axes as a percentage of the total graph size. and graphs of EHP and resistance.5 Report Page WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS The report page is a means of viewing and printing the Power Prediction Program results.3. 5. 5. The page can optionally include the input definition. check the box to launch GOPlot.3. 5. and click OK. It is activated from the Results Page menu or pop-up. It contains the following controls: · Font button · Margin edit box · Tick length edit box · XY Squares Used to specify the font on the particular graph plot. The report page always holds the results of the last performed calculation. Sets the margin on the page around the graph plot as a percentage of the width. 5. but with the non-selected results drawn with a dotted line. or when any key is pressed in the Appendages column of the case table. Click the OK button. 5. which can be used to create a user type. and the new user type is added to the available types on the appendage page · Selected parts · Add button · Remove button · Name · OK button. which may help the clarity of printed output. An edit box containing the name of the highlighted defined appendage. Removes a part highlighted in the selected parts list. Unchecking this box results in all of the curves being shown in black. or just the data relating to the case selected on the Results page. A check box. with the curve for the selected case shown in red.3.3. 16 . the Edit Appendages menu item is taken. which will form the complete user type. Once all the appendages have been set up correctly the OK button returns control to the Cases page.5 Add User Type Dialog This dialog is used when creating new user type appendages. The type name is added to the selected parts list box. which shows whether or not the highlighted appendage will be included in the calculations for the case. The curves are normally displayed in black. Adds a highlighted part to the definition. · OK button 5. An edit box for entering the user type name. A list of the selected parts.6 Edit Appendages Dialog This dialog box allows for individual appendages to be set to be included. In order for the program to accept the new type it must be given a name before closing the dialog. The dialog appears when either. Add parts to the definition either by double clicking on the required types in the list box or by highlighting and clicking on the << Add button.Power Prediction · Show all · Show colour WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS A check box determining whether to show the results of all defined cases. Closes the dialog and effects the changes. The dialog contains the following elements: · Available types A list of appendage types. or to be excluded from case calculations. whether it is used in the base calculation or not. The dialog contains the following elements: · Defined appendages · Selected name · On/Off box · OK button A list of all of the defined appendages. If the file has not been saved before the command activates the Save Dialog and prompts the user for a file name. As the program closes the current data are stored in a file called Lastone. If data exist in the program.. This command can also be accessed via the Save Button on the File Toolbar. The Exit command is used for exiting the Power Prediction Program. This command can also be accessed via the New Button on the File Toolbar The Open command activates the Open Dialog to load a new power prediction file into the program. or changes have occurred. Hull Results Appendages Cases Report Toolbar Help menu Contents Topic search How to use help About All Pages|File Menu · New . · Open · Save · Save As · Exit 17 . or a file has been read into the program and changes have occurred. If a set of data already exists..Power Prediction 5. If data exist in the program a prompt will appear asking if you want to save any changes to the current working file. The Save As command stores the current working power prediction to a file.4 Menus WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS The Menu changes with the notebook page that is selected: All Pages File Menu New Open Save Save as Exit Window Menu Propeller Design. a prompt will appear asking to save any changes to the current working file.ppf. The Save command stores the current values in the program to a file. The New command creates a new blank power prediction file in the program. a prompt will appear asking if you want to save any changes to the current working file. This command can also be accessed via the Open Button on the File Toolbar. The command activates the Save As Dialog and prompts the user for a file name. The About command activates the About Dialog. Toggles the Toolbar on and off.Power Prediction All pages|Window menu · Run Propeller Design WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Initiates a copy of the Propeller Design Program. This feature only works if you have a copy of the Windows version of Propeller design. The Results command activates the Results Page. You can transfer the calculated Resistance data into the Propeller program via the clipboard. as well as setting the location for temporary results files. Once a resistance calculation has been performed use the Copy to Clipboard option from the Results Page. Calc Hull page|File menu · Set up file links Opens a dialog that allow the program to locate the GoPlot source file. The Report command activates the Report Page. 18 . The Topic Search command activates the help topic search. The Appendages command activates the Appendages Page. then run the Propeller Design program and use its EHP Data Page Paste from Clipboard method The Hull command activates the main Hull Page. The Propeller command activates the Cases Page. · Hull · Results · Appendages · Cases · Report · Toolbar All pages|Help menu · Contents · Topic Search · How to use · About Hull Page Set up file links The Contents command activates help at the index page. and any template. Hull page|Calc menu · Calc Run the calculation as set on the page. Activates Windows ‘How to Use Help’ function. This option brings up the Add Speed Dialog. · Show graph · Send to GOPlot 19 . Allows data to be sent to the Wolfson Unit’s GOPlot general purpose plotting program. if available. The graph displays the currently selected column in the results table against the speed. This option is the quickest way to transfer calculated resistance and propulsion data to the Windows version of the Propeller Design Program. The Delete Row command deletes the line that currently has the cursor focus on the Results Page.Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Results Page (There is also a popup menu that is activated by the right mouse button when the cursor is located over the Results notebook. Data are then prepared and sent to the clipboard in an appropriate format. and any template. as well as setting the location for temporary results files. The command activates the Open Dialog. Results page|Edit menu · Insert row · Delete row · Copy EHP to clipboard The Insert Row command inserts a new speed above the cursor on the Results Page. The Paste to clipboard command allows the transfer Speed/Resistance data to other applications via the clipboard. If GOPlot is available the HullPage|File option Set up file links can be used to store the location of GOPlot itself. which can then be run directly from the menu.) File Menu Save EHP data Set up file links Edit Menu & Popup Insert row Delete row Copy EHP to clipboard Show graph Send to GOPlot Results page|File menu · Save EHP Data · Set up File links The Load EHP command loads an EHP curve into the Propeller Design Program. GOPlot can be started automatically by checking the Launch GOPlot option. to show only the selected case data use the Plot Options command. Opens a dialog that allow the program to locate the GoPlot source file. and any required template file. The Show graph command creates a line graph of data and opens the Output Window to display it. Cases to be sent can be specified by checking the appropriate boxes in the dialog box. Data from all of the defined cases are shown. with the line for the selected case highlighted. The Save Appendages command saves the defined set of appendages to a file. See Appendage Files for further information.Power Prediction Appendages Page WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS (There is also a popup menu which is activated by the right mouse button.) Edit Menu & Popup Menu Add Usertype Delete Usertype File Menu Load Appendages Save Appendages Appendages Page|File menu · Load Appendages The Load Appendages command loads a previously saved set of appendage definitions into the program. See Appendage Files in Appendix II for further information. · Save Appendages Appendages Page|Edit menu · Add Usertype This option allows for the definition of a new User Defined appendage type. allowing for their use in subsequent calculations. · Delete Usertype 20 . The User Appendage Dialog box is displayed which allows standard appendage types to be added to or removed from the user type definition. The data saved includes information about any currently defined user types. This option removes the highlighted definition of a User Defined appendage from the list of available appendages. The base values of the selected parameters are initially selected for the new case. The program prompts before deletion. A special dialog box is displayed. 21 .Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Cases Page (There is also a popup menu that is activated by the right mouse button when the cursor is over the Cases table. Deletes the currently highlighted Case from the table. The base value of the parameter is initially selected for all defined cases. Removes the currently highlighted parameter column from the table of Cases. which will be included in the Cases. Adds a new Case into the table. allowing the defined appendages to be selected for inclusion in the calculation or ignored.) Edit Menu & Pop Up Menu Add parameter Delete parameter Add Case Delete Case Clear All Edit Appendages Cases Page|Edit Menu · Add parameter · Delete parameter · Add Case · Delete Case · Clear All · Edit Appendages Adds the currently highlighted calculation parameter to the table of Cases. Allows the user to set the number of the defined appendages. Removes all parameters and Cases from the table. Clicking on it checks or un-checks the option. print preview 22 . This option turns ON or OFF the table borders in the HTML report. Opens a dialog that allow the program to locate the GoPlot source file.Power Prediction Report Page File menu Set up File links WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Edit menu Font Show logo Show borders Include input Include appendages Include graphs Report Page|File Menu · Set up File links Report Page|Edit Menu · Font The font command activates the Font Dialog. Clicking on it checks or un-checks the option. Clicking on it checks or un-checks the option. Determines whether or not the detailed input parameter table is included in the HTML report. · Show logo · Show borders · Include input · Include appendages · Include graphs The report page pop-up includes a standard set of browser options. Determines whether or not detailed appendage parameters are included in the HTML report. The font chosen in the dialog then becomes the font that is presented in the Report Page only Fixed Pitch fonts may be selected This option turns ON or OFF the display of a graphics JPEG logo in the HTML report. and any template. Clicking on it checks or un-checks the option. as well as setting the location for temporary results files. Clicking on it checks or un-checks the option. including printing. Determines whether or not the resistance and power graphs are included in the HTML report. The Print command activates the Print dialog. The Printer Setup command activates the Printer Setup dialog. · Close 23 . This command saves the current graph to a Windows Bitmap file. The Close command closes the Output Window. with the same dimension in pixels as the screen plot.Power Prediction Output Window File Menu Plot Options Print Setup Print Save Bitmap Close Output Window|File Menu · Plot Options · Print Setup · Print · Save Bitmap WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS The plot options command activates the Plot Option Dialog. The Save Dialog is activated and prompts the user for a file name. Operates the Open menu option to load a new power prediction file.5 The Toolbar All Pages New Open Save Run Propeller Design About The toolbar icons change depending upon the current notebook page that is selected. Operates the Save menu option to save the current data to a power prediction file. Once a resistance calculation has been performed use the Copy to Clipboard option from the Results Page. Initiates a copy of the Propeller Design Program. then run the Propeller Design program and use its EHP Data Page Paste from Clipboard method Runs a calculation using the data as set.Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS 5. You can transfer the calculated Resistance data into the Propeller program via the clipboard. New Open Save Run Propeller Design · · Calculate About 24 . Operates the About Dialog. This feature only works if you have a copy of the Windows version of Propeller design. Icons that are available to all pages are listed below: · · · · Operates the New menu option to clear all data. to the weight of a volume of water with a cross section of the vessel's maximum section and a length of the vessel's waterline length. the program displays the required values and units on the status line when the mouse pointer is held over the relevant data field. Depending upon the method used this is either the moulded beam or the extreme beam of the vessel at the static waterline. The valid ranges of input data are shown in section 6. The half angle of entrance at the forward end of the vessel's waterline. to a rectangle defined by the vessel's beam and length. excluding appendages. or calculated: Hull Inputs As some of the parameter requirements differ between calculation methods. in metres or feet. at the intersection of the still water surface and the stem. Cp (Prismatic coefficient) Cw (Waterplane coefficient) Deadrise Displacement Draught Half angle LCB LCF 25 .Power Prediction 6.2. in degrees. Beam Bulb Area Bulb Ht. in metres or feet. for the Wolfson High Speed method it is the deadrise angle at the transom section. The ratio of the displacement of the vessel. The height of the centre of cross sectional area of the bulbous bow above the keel line.1 WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS POWER PREDICTION GUIDE Nomenclature Within the program the following items are set. The longitudinal centre of buoyancy defined as a percentage of the waterline length forward of midships. The longitudinal centre of flotation defined as a percentage of the waterline length forward of midships. For the Savitsky method this is the average angle of deadrise over the vessel's planing surface. The ratio of the waterplane area of the vessel. in degrees. in square metres or square feet. in metres or feet. The maximum draught. The transverse cross sectional area of the vessel's bulbous bow. BAR The blade area of the propeller divided by the area of a circle whose diameter is the diameter of the propeller.0 6. The weight of the vessel in tonnes or tons. The First Last and Increment Edit boxes are shown in the top right of the Hull Page.g. The angle that the propeller line makes with the buttock line. 0. The area of the transom immersed when stationary.g. Alternatively if a number greater that 1. usually it is Length or Volume Froude number limited. with negative values reducing its size and positive values increasing it. and the required set of speed is set by altering these values. Note that in the Tugs & Trawlers method this value is taken as the ‘Displacement Length’ which is the mean of the waterline length and the length between perpendiculars.Power Prediction Length WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS The length of the vessel. in square metres or square feet. The valid range of speed is a function of the calculation method and hull parameters. 1. in metres or feet. If the number entered is less than 1. Bow up trim is positive. The shape coefficient's main effect is on the Wake Fraction.0004. T/Amax Thrust arm Transom Area Trim VCG 26 . in metres or feet. Roughness Shape Factor Speeds All speeds entered and shown within the program are in knots. The ratio of the cross sectional area of the transom immersed when stationary. the height of the centre of gravity above the keel line. Angle Prop. bow down trim is negative. Diam. The trim is defined as the difference in draught measured at the FP and AP. and the cross sectional area of the vessels maximum section. on the static waterline. in metres or feet.0 is entered then this is used as a multiplication factor for Cf. Vertical Centre of Gravity. A coefficient relating the shape of the vessel's afterbody. The perpendicular separation of the VCG from the extended propeller shaft line.1.0 then it is used as an addition to the calculated skin friction coefficient (Cf). e. The longitudinal attitude of the vessel relative to its datum. The hull roughness allowance. in degrees. The ratio of the pitch of the propeller to its diameter. The diameter of the vessel's propellers. appropriate to its trim and displacement. Typical values:Shape Coeff -10 0 10 Stern type V shaped sections Normal section shapes U shaped sections with Hogner stern Pitch/Diam Prop. and so can be used as a form factor term e. in metres or feet. If the deadrise is greater than 20 degrees. The empirical porpoising stability calculated by the Savitsky prediction. calculated by the Savitsky prediction. which indicates erroneous results. (Vessel speed . Length Porpoising Resistance Rotative Efficiency Thrust Deduction Trim Wake Fraction 27 . excluding appendages. The ratio of the efficiency of the propeller behind the ship. then results are given assuming a 20 degree deadrise. in kN or tons f. then the estimated value will be used and the estimated value displayed on the results file. The calculated trim from the Savitsky planing calculation.resistance)/thrust. calculated by the Savitsky prediction. which is (thrust .Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Wetted Area The wetted surface area at rest in square metres or square feet. (1-thrust deduction factor)/(1-wake fraction). to the open water efficiency A factor relating the vessel's required thrust to the resistance. Hull Outputs The results of calculations fall into the following categories: Beam EHP Hull Efficiency The wetted beam at speed. Where no result is given then the condition is out of range of the empirical results and is indeterminate. Enter a value of zero to force calculation. All the methods that require a wetted surface area have routines that can estimate the area.Speed of advance)/Vessel Speed. in degrees. The wetted length at speed. The Effective Horsepower in kW or HP. A factor relating the vessel speed to the speed of the flow through the propeller (speed of advance). An overall hull efficiency factor. If the entered area is less than half the estimate or greater than twice the estimate. The predicted calm water resistance of the vessel. This may sometimes exceed the LWL. Wetted Area Coefficients: Cp .Draught . .00 -2.Cw .16 Envelope <= <= <= <= <= <= <= CP CB CW L/B B/T LCB Fn <= <= <= <= <= <= <= 0.Bulb Area .45 0.55 0.00% 0.90 2.63 3.Transom Area .Displacement .BAR .Prop.85 0. Diam .Power Prediction 6.84 0.Trim Special: Bulb Ht.00 3.50 4.2 WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Calculation method input reference & ranges Single Screw Ships Input Reference Base Data: Length .00% 0.85 28 .LCB .Beam .95 9.Shape Factor Range Checks 0. 63 3.90 2.Cw .Trim Special: Bulb Ht.85 29 .LCB .Pitch/Diam .Power Prediction Twin Screw Ships Input Reference WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Base Data: Length .Bulb Area .84 0.Beam .45 0.Shape Factor Range Checks 0.Wetted Area Coefficients: Cp .00% 0.00 -2.50 4. .Displacement .Transom Area .Prop.95 9.Draught . Diam .16 Envelope <= <= <= <= <= <= <= CP CB CW L/B B/T LCB Fn <= <= <= <= <= <= <= 0.00 3.55 0.85 0.00% 0. 30 .1 <= <= <= <= <= <= <= CB CP L/B B/T LCB Angle of Entry Fn <= <= <= <= <= <= <= 0.0° 0.Prop.725 6.LCB .5 Envelope Within ranges.80% 46.Power Prediction Tugs and Trawlers Method Input Reference WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Base Data: Length .703 0.Wetted Area Coefficients: Cp .20 4.90 -8.Beam .Displacement .365 0.00% 10.0° 0. Diam Special: Half angle Range checks 0.00 1.Draught .00 2.50 3. Diam 6.Power Prediction BSRA Method Input Reference Base Data: Coefficients: Range checks 4.Beam .LCB Prop.00% 0.Displacement .23 0.36 0.24 31 .80 3.65 2.Draught .15 Envelope <= <= <= <= <= L/D1/3 CB B/T LCB Fn <= <= <= <= <= WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Length .54% 0.12 -2.96 3. Beam .Displacement .33 -2.5 3.Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS NPL Round Bilge Craft Input Reference Base Data: Coefficients: Range checks 4.33 -7.00 Envelope <= <= <= <= <= L/D1/3 L/B LCB Fn Prop Angle <= <= <= <= <= 8.30 7.22 13.24 7.Wetted Area Prop.LCB .00% 1.00% 0. Angle 32 .00 Length . 55 4.60 13.00 Envelope <= <= <= <= <= L/D1/3 CB B/T Fn Prop Angle <= <= <= <= <= 11.Displacement .Beam .30 0.Wetted Area Prop.60 0. Angle 33 .Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Series 64 Input Reference Base Data: Coefficients: Range checks 8.Draught .10 7.00 1.00 0.35 2.00 Length . 60% 0.25 13.LCB .00 -4.Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS SSPA Series Input Reference Base Data: Coefficients: Range checks 3.00 8.00 Length .40 7.Beam .Displacement .00 -8. Angle 34 .00 Envelope Within ranges <= <= <= <= <= B/T L/D1/3 LCB Fn Prop Angle <= <= <= <= <= 4.10% 1.00 6.Draught .Wetted Area Prop. Beam .00 13.00% 0.LCB .Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Davidson Regression for Round Bilge and Planing Craft Input Reference Base Data: Length .00 35 .00 -8.T/Amax Range checks 0. Angle Special: Half angle .00 1.90 0.00 2.Wetted Area Coefficients: Prop.Displacement .Fn Prop angle <= <= <= <= <= <= 17.00 Envelope <= <= <= <= <= <= L/B L/D1/3 LCB T/Amax Vol.00% 0.Draught .00 7.99 2.90 13. Thrust Arm . Angle .Beam .Displacement .LCB Prop.00 Length .Deadrise 36 .VCG .Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Savitsky Planing Prediction Input Reference Base Data: Coefficients: Range checks Planing <= Speed knots <= 100. Power Prediction Delft Systematic Yacht Hull Series Input Reference Base Data: Coefficients: Range checks 0.51 4.38 -10.00% 2.70 2.40 -10.00% 0.10 Envelope Within ranges. <= <= <= <= <= <= <= Cp L/D1/3 LCB L/B B/T LCF Fn <= <= <= <= <= <= <= WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Length - Beam - Draught - Displacement - LCB - Wetted Area Cp - LCF 0.60 8.50 5.00% 5.00 20.00 5.00% 0.60 37 Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Wolfson Unit Chine Hulls Input Reference Base Data: Coefficients: Range checks 4.0 2.3 0.5 7.0 Envelope <= <= <= <= L/D1/3 L/B Fv Prop angle <= <= <= <= 8.75 5.75 3.00 13.00 Length - Beam - Displacement Prop. Angle 38 Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Wolfson Unit Round Bilge Input Reference Base Data: Coefficients: Range checks 4.5 2.9 0.5 7.0 Envelope <= <= <= <= L/D1/3 L/B Fv Prop angle <= <= <= <= 6.8 5.4 2.75 13.00 Length - Beam – Displacement – Wetted Area Prop. Angle 39 2 7.Power Prediction Wolfson Unit Catamarans Input Reference Base Data: Coefficients: Range checks 6.Displacement . Angle 15 1.00 Envelope Within ranges.3 7 0.5 <= <= <= WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Length .Beam .Wetted Area Prop.0 13.00 40 . <= <= <= <= L/D1/3 <= L/B Fn Prop Angle 9. 0 6.0 25.0 6.Disp ratio 10 6.0 13.3 Units Data within the program are held either in metric or imperial units.metres Tonnes Degrees kN kW Imperial feet sq.0% 5.0 2 -20.Beam .5 7. Measure Length Area Displacement Angles Resistance Power Metric Metres sq. Angle .0 6 5 L/B 4 3 2 1 2 4 6 8 Length .Displacement .Deadrise <= <= <= <= <= <= L/D1/3 L/B LCB Fv Prop angle Deadrise angle <= <= <= <= <= <= 9.LCB Prop.0 Envelope 7 WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Length .Power Prediction Wolfson Unit High Speed Input Reference Base Data: Coefficients: Range checks 3.feet tons degrees tons force horse power 41 .0 0.0% 0. The left-hand portion of the screen is reserved for details of the individual appendages. (b) User Defined This is an appendage created from up to ten standard types such as a P-bracket comprising a strut (control surface) and a bossing (cylinder). When a User Defined appendage is selected. those currently associated with the hull. a further list box is displayed below the Appendages Defined box.4 Appendages WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS There are two types of appendage used by the program: (a) Standard This is an individual component such as a cylinder (shaft) or bilge keel.e. Appendages can be added or removed from this list by using the Add and Remove buttons located between the Appendages Defined and Available Types list boxes. Firstly they allow appendages to be defined from Standard types or from User Defined types. 42 . The Appendage page and associated pop-up menu serve two purposes. a set of edit boxes showing its parameters is displayed. i. the standard and user defined appendage types. Initially this list is empty.Power Prediction 6. and values may be entered or edited as required. In the middle of the page is a list of the Appendages Defined. When one of the defined appendages is selected in the Appendages Defined list box. allowing selection of the individual parts of the appendage.e. The page is divided into three regions: On the right is a list of the Available Types. i. Secondly they allow User Defined types to be created from combinations of the Standard types. mean thickness of keel 43 .4. Input Parameters Length Depth Thickness (metres/feet) (metres/feet) (metres/feet) .mean depth of keel . with Cf calculated with the vessel’s Reynold’s number.length of bilge keel .1 Standard appendages WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Bilge keels These are taken as paired sets of low aspect ratio appendages.Power Prediction 6. with Cf calculated with the vessel’s Reynold’s number.length of skeg .mean thickness of skeg 44 . with Cf calculated with the vessel’s Reynold’s number.depth of skeg .mean chord of control surface .. yacht fins.thickness/chord ratio of control surface Input Parameters Length Depth Thickness (metres/feet) (metres/feet) (metres/feet) . stabilisers etc.mean span of control surface .Power Prediction Control Surfaces WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Used for rudders. Input Parameters Span Chord t/c Skegs Centreline appendages. (metres/feet) (metres/feet) . angle of cylinder to flow Air Drag Frontal area pressure drag.0 45 . typically 1.drag coefficient.diameter of cylinder .cross sectional area Drag Coefficient . Input Parameters Area (sq.length of cylinder .feet) . using the standard properties of air to calculate their resistance.Power Prediction Cylinders Shafts and bossings. WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Input Parameters Length Diameter Angle (metres/feet) (metres/feet) (degrees) .metres/sq. length of appendage. using the standard properties of seawater to calculate their resistance.cross sectional area Drag Coefficient .metres/sq. typically 1. Input Parameters Area (sq. Cf calculated with their own local Reynolds number.cross sectional area (metres/feet) .metres/sq.feet) . Input Parameters Area Length (sq.feet) .Power Prediction Additional Drag WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Frontal area pressure drag.0 Additional Friction Used for appendages with only a skin friction component. used to calculate Reynold’s number 46 .drag coefficient. 4. or highlight tit and click on the << Add button. of keel/bulb combinations. Either double click on the appropriate type in the Available Types list box. and click the Remove >> button. Alter the values to suit. Number of etc. The rest of the page is a table of case conditions 47 .3 Removing an appendage To remove an appendage highlight it in the Appendages defined box.4. 6.5 Cases The program can calculate results for a series of hulls that are variations of the parameters that define the base vessel. The edit cases screen is divided into two regions: On the right is a list of the parameters required for defining the base vessel. To create new user types take the Add Usertype option from the Edit or pop-up menu. with any of the parameters changing. Appears.2 Adding a new appendage To create new appendages follow this procedure:1. 6. 6. The type name is added to the Appendages defined box. 2. Cases are defined by changing one or more of the parameters entered as base data on the Hull Page. In order for the program to accept the new type it must be given a name before closing the dialog.g. A dialog box is displayed which allows standard appendage types to be added to or removed from the user type definition. e.4.Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS 6. Name. Up to 10 additional cases can be defined. If the appendage is a standard type and a set of edit boxes containing its defined characteristics. If the appendage is a User type enter the name and number of and then highlight the individual components in the lower list box and enter their parameters. Now highlight the appendage in the Appendages defined box. or changing the combination of appendages that are added to the naked hull. which is defined by the calculation method.4 User defined appendages User defined appendages are combinations of standard appendage types which can be grouped together in order to model features such as propeller brackets. select the appropriate column and row and type a new value. The parameter values for the new case will be taken initially from the base vessel definition.Power Prediction WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS To Add a parameter to the table. either double click the parameter in the list. To Remove a parameter from the table. If the parameter selected is the number of appendages. To Edit the values of parameters in the case table. To Add a new case take the Add Case option in the Edit or pop-up menus. i. that set on the Hull page. or highlight it and take the Add Parameter option in the Edit or Pop-Up menus. To Remove a case select the appropriate row in the table and take the Delete Case option from the Edit or pop-up menus. a special dialog box is displayed. allowing the defined appendages to be selected for inclusion in the calculation or ignored. select the appropriate column and take the Delete parameter option in the Edit or pop-up menus. 48 .e. Midship section coefficient. which is the moulded volume of the ship/(waterline length * waterline beam * mean draught. Block coefficient. Free checking only looks for overall ranges of data. The beam of the vessel. which is CB/Cp. bilge keels etc. propeller shafts. The transverse sectional area of the bulb at the position where the still water surface intersects the stem. Water plane area coefficient. The calculated results for the vessel data set on the Hull page. on the Hull page. in metres or feet. measured between the load waterline and the vessel's centreline. Cases form a way in which hull parameter variations may be checked. The position of the centre of the bulb area above the keel line. which is the moulded volume/(waterline length * (area of the midship section)). in the Results page. The results calculated for the case number. A list box containing the different parameter checking options. 49 . rudders. in metres or feet. the (water plane Case n results CB Checking CM Cp Cw Displacement The full displacement of the vessel in tonnes or tons. but results may not be calculated in certain circumstances.Power Prediction 7. Prismatic coefficient. either extreme or at the waterline. A list box on the Hull page containing the list of the published methods built into the program for calculating resistance. A notebook page allowing calculation cases to be set up.g. Substituting the hull parameters. in square metres or square feet. Items additional to the main hull e. forms a case. with alternative values set on this page. in degrees. Strict checking ensures that no calculation is made if any parameter values fall outside the allowable ranges and envelopes of tested data. Click on the tab to view the data.0 GLOSSARY WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Angle of Entry Appendages Base results Beam Bulb Cross Sect Area Bulb Centreline Height Calculation method Cases The half angle of entrance. None allows the program to attempt any calculation. which is area)/(waterline length * waterline beam). The Effective Horsepower in kW or HP.resistance)/thrust). Froude No.root g. An addition to the ITTC 1957 frictional coefficient. = V / gL .5 LBP expressed as a percentage of LBP. which is ((thrust . The waterline length to beam ratio. If the deadrise is greater than 20 degrees.Power Prediction Deadrise Angle (mean) Draught EHP Froude Number Hull Efficiency Immersed Transom Area Length/Beam Ratio.0004. It is positive forward of midships. The vessel draught (to the keel line) excluding appendages in metres or feet. (speed over sq. to the open water efficiency.length) An overall hull efficiency factor. The predicted calm water resistance of the vessel. for Wolfson High Speed. which is (1-thrust deduction factor)/(1-wake fraction). The angle that the propeller shaft makes with the keel. Typical values might be:Shape Coeff -10 0 10 Stern type V shaped sections Normal section shapes U shaped sections with Hogner stern Propeller Shaft Angle Roughness Coefficient Relative rotative efficiency Resistance Shape Factor Thrust Deduction Factor A factor relating the vessel's required thrust to the resistance. The ratio of the efficiency of the propeller behind the ship. Coefficient relating to the afterbody form. The shape coefficient's main effect is on the Wake Fraction. used to add the effect of hull roughness to the calculated resistance. the transom deadrise. The area of the immersed portion of the transom at zero speed. L/B LCB Porpoising WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS For Savitsky. in kN or tons f. with negative values reducing its size and positive values increasing it. Its standard value is taken as 0. in degrees. 50 . The empirical porpoising stability calculated by the Savitsky prediction. measured in square metres or square feet. the average angle of deadrise over the vessel's planing surface. The longitudinal centre of buoyancy forward of 0. then results are given assuming a 20 degree deadrise. Where no result is given then the condition is out of range of the empirical results and is indeterminate. Bow up trim is positive. in metres or feet. which is ((Vessel speed .Power Prediction Thrust Moment Arm WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS The perpendicular distance between the centre of gravity and the thrust line. Transom/Max Area Ratio Trim Units VCG Wake Fraction Wetted Length Wetted Surface Area 51 . This may sometimes exceed the LWL. A factor relating the vessel speed to the speed of the flow through the propeller (speed of advance). the program will calculate its value according to procedures given in Ref. The longitudinal attitude of the ship relative to its datum. It is defined as the difference in draught between two points on the base line. in metres or feet. calculated by the Savitsky prediction. The wetted surface area of the vessel at rest. separated by the waterline length. and the cross sectional area of the vessel's maximum section. The units used by the program are either metric or imperial.Speed of advance)/Vessel Speed).2. The height of the centre of gravity above the keel line excluding any appendages. 1. The ratio of the cross sectional area of transom immersed when stationary. Positive if the thrust line is below CG. The wetted length at speed. negative if above. which indicates erroneous results. If entered as zero. bow down is negative. Range. Pressing the OK button continues the checking process in order to highlight other boundary errors. Envelope. usually because its value is zero. e. In each case the allowable range is shown within the error message. CB or L/B lies within the allowable range of values. Unless the No Checking option is selected all data are checked before a calculation is performed. 1.0 ERROR MESSAGES WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Errors are displayed in a message box. The program checks that an individual parameter.g. 52 . File Input/Output errors File errors arise either because the file contents do not correspond to the required File Format when loading data from disc. but does not perform a calculation. To continue operation the OK button must be clicked.Power Prediction 8. Pressing the Cancel stops checking immediately. or because the file name or path is invalid. 2. There are two boundaries that the program checks. Certain of the calculation methods are only applicable to combinations of parameter ranges. which form an envelope of acceptable values. The box describes the type of error. Data boundary errors Data boundary errors occur when the program finds that the input values set fall outside the boundaries of the calculation methods. Within the program there are three types of error messages: Data Checking Data Boundary File Input/Output Data Checking Errors Data checking errors arise whenever a value which is required by the program for calculation is not set correctly. 29. 7th HISWA Symposium 1981. 'Series 64 Resistance Experiments on High Speed Displacement Forms'. 'Hydrodynamic Design of Planing Hulls'. Vol. Marine Technology. Transactions of the Royal Institution of Naval Architects. Swedish State Shipbuilding Experimental Tank Report. No. No. 13. Mennen. Resistance and Stability of the Delft Systematic Yacht Hull Series’. 'A Power Prediction Method and its Application to Small Ships'.3. Holtrop and G. November 1971 7. No.F. November 1971 5. Vol. International Shipbuilding Progress. International Shipbuilding Progress. International Shipbuilding Progress. Fast Displacement Vessels. 'A Statistical Power Prediction Method'. Vol. 'The NPL High Speed Round Bilge Displacement Hull Series'.. including a Study of the Influence of Spray Strips'. Vol. And van Gulik A.F. 16. Onnick R. Molland A. 1996 15.An Overall Presentation'. Williams. Vol. Yeh.2. Parker.F. Holtrop. Molland A. Vol. 1966 6.. Transactions of the Royal Institution of Naval Architects. Keuning J. 18. 18. Hydrodynamics of High Speed Craft. October 1978 2.R. and Couser P.A. Davidson Laboratory Report. 1973 11. 14. Marine Technology. An investigation into the effect of prismatic coefficient on catamaran resistance.1.4' by The Royal Institution of Naval Architects 8. Oct 1964 12. Onnick R. Holtrop and G.Power Prediction APPENDIX I REFERENCES WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS 1. ‘Geometry. 'Resistance of Transom-Stern Craft in the Pre-Planing Regime'.Wellicome J. 1997. 'Regression Analysis of the Resistance Results of the BSRA Series'. 14th HISWA Symposium 1996. Savitsky. 'A Statistical Re-Analysis of Resistance and Propulsion Data'.1. Resistance experiments on a systematic series of high speed displacement catamaran forms: variation of length-displacement ratio and breadth-draught ratio. Gerritsma Prof J. 53 . International Shipbuilding Progress. Bailey. 31. Mercier and D. July 1982 3. Savitsky. 1969 10. And Versluis A. Lindgren and A.. Performance Prediction of Chine and Round Bilge Hull Forms. 'The BSRA Methodical Series . International Shipbuilding Progress. SIT-DL-73-1667... Sabit. Versluis A. Vol. 'Systematic Tests with Small.65. Mennen. van Oortmerssen. 138. Vol. Robinson John.R. 139. RINA November 1999. published as the 'Maritime Technology Monograph No. Transactions of the Royal Institution of Naval Architects. 'An Approximate Power Prediction Method'. and Lee A. July 1965 9. 25. November 1984 4. Vol. ‘The Bare Hull Resistance of the Delft Systematic Yacht Hull Series’. Power Prediction 17. the Appendage Page.75 Displacement:35.00 54 .000 Bulb area:0.0 Last Speed:16.000 Prop P/D:0 Trim:0.00 14. A typical file looks like: Wolfson Unit Power prediction Data Title:Maxi Yacht.0 Speed Increment:1 Speeds:4 13.55 Waterplane Coeff:-3 Prop Diam:0.00 15.000 Thrustarm:0. Calc type:10 Check type:3 Units:1 Show graph:0 Length:20. and Cases Page and the names of other files used.000 Deadrise:0 Bulb height:0. Each item in the file is prefaced by its meaning.000 BAR:0 Prop shaft angle:0 VCG:0. followed by a colon..7 Draught:.050 Beam:4.PPF The main file type used in the program stores all of the data from the main Hull Page.000 Shape factor:0 Half entrance angle:0 Transom/Max area ratio:0 Roughness:0 First Speed:3. APPENDIX WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS II FILE FORMATS The program uses three types of file: Power Prediction Files Appendage Files EHP Data Files Power Prediction Files *.000 Prismatic Coeff:.000 Transom area:0.5 LCB:-3 Wetted Area:0. 0004 .00000 0.10000 :On 1100000000 2 :Control Surface Keel 100 0.0001 WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS 55 .68000 3.0002 .Power Prediction 16.00000 :On 0000000000 Cases defined :3 Case parameters :2 Case data: Case\Param Base Case 1 Case 2 Case 3 Appendages 3 2 1 0 Roughness 0 .10000 :On 1000000000 3 :Additional friction Bulb 100 2.75000 2.00 Report file: User types:0 Appendages:3 1 :Control Surface Rudder 100 0.00000 0.00000 3.00000 0. 50000 0.15000 Boss 1 0.. A typical file looks like:- Wolfson Unit Power prediction Appendages User types:1 1 :P-Bracket 2 1 3 0 0 0 0 0 0 0 0 Appendages:2 1 :Control Surface Rudders 55 0 0 0.20000 0.25000 0.Power Prediction Appendage Files *.20000 0.00000 :On 0000000000 User definition:P-Bracket No:2 Strut 1 0.00000 56 .50000 0.00000 0.00000 0.PPA WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS This file saves only the data from the Appendage Page.20000 0.14000 :On 0000000000 2 :P-Bracket Brackets 212 0. kN 1 Basis Ship 11 20.073 0.034 -0. and the fifth contains a descriptor.003 0.064 0. Speed. Wt.229 26. and subsequent lines contain.207 22.952 29.kts Resistance .000 53.007 -0.Power Prediction EHP Data *.811 28.876 30.000 38.000 42. Resistance Wake Fraction and Thrust Deduction.000 41. however this program ignores data on this line. Line 6 contains the number of speeds present in the data.082 0.568 23. Column 1 must be speed in knots. A typical file looks like: - A test Speed .999 27.220 0. The file format is compatible with the input to the Wolfson Unit Propeller Design Program. and t shown in the Results Page.605 25.PPG WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS The EHP data file type stores the values of Speed. The fourth line contains the number 1.019 -0.097 0.067 0.274 -0.275 57 .006 0.116 0.024 -0.063 0.013 -0. Resistance.820 21.143 0.000 44. The first line contains a descriptor.000 39.000 49.007 0.001 0. Column 2 is Resistance in ‘kN’ or ‘tonf’.177 0.000 46.029 -0.104 24. followed by two lines describing the content and units of the first two columns.006 0.000 36.000 35.000 33. ......... 28 Deadrise ..... 13 Base Data .................. 45 Angle of Entry .......................... 13.... 6 About Dialog ... 49 CM .......................................... 12................................................................42.... i Draught ............. 14 B BAR .................................................................... 25 Length............ 49 Cylinders ........ 49 Bulb Ht............................... 5......... 13 Bulb Area ............................................................................. 28................... 17 LCB ........................... 12 Hull Efficiency . 49 Appendages page ....................................................................................... 2...... 25............................ 11 Appendages Page ........................................................................................................ 25 Bulb Centreline Height .............. 50 G GETTING STARTED .......... 49 Coefficients....................................... 26......... 12 I Immersed Transom Area ..........Power Prediction INDEX WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS A A simple calculation .... 25........................ 49 Check box....... 12.............. 11 Hull Page ................. 10 EHP ......................................................... 11 Bulb area ................................................................................. 25 Button..................................... 25....................................... 49 Beam ...................................... 28 INTRODUCTION ................................................................... 27........................................ ......................................................... 12................. .............. 13................... 12................................ 15 Add User Type Dialog ..... 12 Base results........... 46 Additional Friction ....... 17 58 .......................... 5. 49 DONGLE.................................................................................... 25...... 50 Input reference ... 50 Displacement ................ 5................................ 50 List Box ............ 49 Cases page ............................................................................. 49 Appendages ....................... 12........................................................................................................................................................... 25............ 16 Edit box...... 13..................................... 50 ERROR MESSAGES .................................................. 7 Additional Drag ... 27. 13........... 27 Length/Beam Ratio....................... 11 Cases Page. 14 CB................................................................. 46 Air Drag .............................12....................... 50 E Edit Appendages Dialog .... 25.................. 44 Cp ........ 10 Checking..... 11 C Calculation method .......... 12.......... 49 Bilge keels .................................................................. 13 Comparing cases ......... 49 H Half angle .............................................. 8 CONFIGURING THE SYSTEM ....................... 52 F FILE FORMATS .............................................13...................................................................................... 45 D Data ranges .................................................................................................................. 16 Adding an appendage ....... 54 Froude Number .................................... ii Control Surfaces ............................... 5 GLOSSARY .............................................. 25 Heading....................... 49 Bulb Cross Sect Area ................................ 25. 49 Cases ..................................................................................................................................................................................................................................... 27...... 1 CONTENTS . 49 Cw......................................................... 11 M Menu .... 43 Browser ............................47............................................ 5 Menus ............. 1 L Lastone ............. 50 LCF ....... 50 Hull page ........................................ 13..................................... 10 Shape factor ......... .............. 12........................................ 51 U Units ........13...................... 47 V VCG ................................ 27............... 24 Thrust arm .... 26 Tabbed notebook ................................................................................................ 13 Speeds...... 5 Transom area ....................................................................... 26.................................................................... 15 Resistance.............. 51 Wetted Area ........... 13......................................................................... 25 O Output Window .......................... 26.................................... 51 Wetted Length ..... 50 Skegs ............. 5 The Toolbar ....................................................... 13 Last ................................................ 41.......... 51 Thrust Deduction........ 12............................... 50 Prop.................. 51 User defined appendages ......................... 13 WOLFSON UNIT FOR MARINE TECHNOLOGY AND INDUSTRIAL AERODYNAMICS Speed ..... 13 Increment .............. 26.......................................... 11 Report Page ........... 11 T T/Amax.................. 53 Report page ..... 11..................................................... 50 S Selection box.......................27.......................................... 13 Prop........................................................................................ Diam ............................ 25 PROCESS DESCRIPTION ................ 15 P Pitch/Diam................. 50 Toolbar ..................... 13 First .................... 5...................................................................... 51 Trim......26............. 27........... 26 Plot Options Dialog........Power Prediction N Nomenclature......... 44 Special data ................ 10 Prop Angle.............. 26......... 26 Transom/Max Area Ratio ...................... 5 String grid ........................................................ 51 Vessel Data ......................................................... Angle... 13 Transom Area .................. 27................................. 2 PROGRAM REFERENCE .............27..................................................................... 26 R REFERENCES ..... 27.............. 13...................................................................................................................................... 10 Tabbed Notebook ....................... 27 Roughness . 13 Rotative efficiency ...................................... 50 POWER PREDICTION GUIDE .......................................... 12.................................................................... 12 W Wake Fraction .......... 50 Rotative Efficiency................... 26 Shape Factor .....13................................... 50 Results page........................... 5........ 5...... 51 59 ......... 26 Status Line .........13...................... 13..................................................................................... 13................. 15 Porpoising..