Propeller Design Manual

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In addition to the

In addition to the manual there manual there is either a 3½" disc ois either a 3½" disc or a CD-Rom supplied with this packager a CD-Rom supplied with this package. . NewNew users will be provided with a hardware key or 

users will be provided with a hardware key or DongleDonglefor software protection.for software protection.

PROTECTION SYSTEM PROTECTION SYSTEM Single user option

Single user option

This program utilises a hardware key or 

This program utilises a hardware key or DONGLEDONGLE which fits into either thewhich fits into either thePrinterPrinteror or USBUSB port of port of  the com

the computer, if uputer, if using a printer port tsing a printer port type, the printer leype, the printer lead then ad then plugs into the plugs into the back of the back of the key. key. TheThe individual programs check for the presen

individual programs check for the presence of this keyce of this key. . If it is not found, a warning is gIf it is not found, a warning is given, place iven, place thethe DONGLE

DONGLE in the port before continuing.in the port before continuing.

 Netw

 Network optioork optionn

The network option is a version that provides network license protection using just one key. The The network option is a version that provides network license protection using just one key. The network option works with TCP/IP networks.

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. 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 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 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, 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.

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 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 automatically installed. Connect the hardware dongle key to the parallel or USB port and start the server by selecting it from the Start menu.

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 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 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 6666 and click Apply and Close. Now click the ‘Retry to start server button’ which should successfully star

start the server. Don’t worry about the met the server. Don’t worry about the message ‘IP Security not loaded’ as this can ssage ‘IP Security not loaded’ as this can be be set up later if set up later if  required. You can now click OK to place the Security server in the system tray. You can at any time 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.

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 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  security server. On each server computer run the driver install program Sl2inst.exe on the disk   provid

 provided. Click ed. Click the ‘Install’ the ‘Install’ button tbutton to o copy the acopy the appropriate devicppropriate device driver e driver file for the file for the opeoperating systemrating system and add the registry entries. Click the ‘Uninstall’ button to remove the drivers. A command line version 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’ 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 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.

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CONFI

CONFIGURGURING THE ING THE SYSTSYSTEM...EM... 11

INTRO

INTRODUDUCTION...CTION... 11

PROCE

PROCESS SS DESCDESCRIPTIORIPTIONN ... 22

GETTI

GETTING STARTENG STARTED D ... 44

PROGRA

PROGRAM M REFERREFERENCE...ENCE... 99 Ge

Geneneral ral cocontrontrols...ls... 99 Dis

Display play pagepagess ... 1111 Dial

Dialog og boxboxes...es... 1313 Me

Menus.nus... 1515 Too

Toolbar...lbar... 1919

PROPE

PROPELLELLER DESIGN GUR DESIGN GUIDEIDE ... 2121

GLO

GLOSSARSSARY...Y... 2727

ERROR MESSA

ERROR MESSAGES...GES... 2929

APPE

APPENDINDIX X I I RefRefereerencnces es ... 3131

APPE

APPENDINDIX X II II File File FormFormats...ats... 3232

INDEX 36 INDEX 36

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1.0 CONFIGURING THE SYSTEM

1.0 CONFIGURING THE SYSTEM

Configuration of the system is performed by a file on the program disc entitled

Configuration of the system is performed by a file on the program disc entitled SETUP.EXESETUP.EXE. Before. Before

undertaking the configuration however, take a backup copy of the disc supplied, and then follow this procedure undertaking the configuration however, take a backup copy of the disc supplied, and then follow this procedure with th

with the backup copy :-e backup copy

:-A.

A. Place Place the the program program disc disc in in drivedriveAA..

B.

B. From From the the File File Manager Manager runrunSETUPSETUPfrom the floppy.from the floppy.

C.

C. Follow Follow the the installation installation prompts. prompts. The The sub-directory sub-directory onto onto which which the the program program will will be be installedinstalled defaults to

defaults to C:\Program Files\Wolfson\PropsC:\Program Files\Wolfson\Props, and the Windows group file defaults to, and the Windows group file defaults to Wolfson

Wolfson. . These mThese may be ay be changed if changed if requirrequired.ed.

D.

D. The The installation installation will will automatically automatically add add a a devicdevice e driver driver required required for for correct correct operation operation of of thethe  protecti

 protection syson systemtem. . WindWindows wows will neill need to be ed to be restarted irestarted in orden order for it to take er for it to take effecffect.t.

The program may then be run from the program manager as normal. The program may then be run from the program manager as normal.

2.0

INTRODUCTION

2.0

INTRODUCTION

This manual describes a program enabling propeller design calculations to be performed, using standard This manual describes a program enabling propeller design calculations to be performed, using standard series data, either provided o

series data, either provided on the n the disc or input by disc or input by the user. the user. It is assumed It is assumed that the user has a that the user has a basicbasic knowledge of the machine and the operation of programs under Windows 3.1 or ‘95.

knowledge of the machine and the operation of programs under Windows 3.1 or ‘95.

The Propeller Design Program computes propeller performance, using various design and off-design The Propeller Design Program computes propeller performance, using various design and off-design methods, from standard Gawn and Wageningen B-series propeller charts or propeller data input by the methods, from standard Gawn and Wageningen B-series propeller charts or propeller data input by the user.

user. Data for Kaplan propellers operating in Data for Kaplan propellers operating in nozzles nozzles are also available.are also available.

The program provides a rapid means of designing a propeller or investigating the influence on The program provides a rapid means of designing a propeller or investigating the influence on  perform

 performance ance and eand efficifficiencency of varioy of various desius design paramgn parameteeters.rs.

For each propeller, data are held as a series of KT and KQ versus J curves, one curve for each For each propeller, data are held as a series of KT and KQ versus J curves, one curve for each Pitch/Diameter ratio.

Pitch/Diameter ratio. The program's meThe program's method of calculation is based thod of calculation is based upon locating upon locating data points withindata points within the KT-KQ-J curves. Various analysis methods can be used, depending on the propulsion data available the KT-KQ-J curves. Various analysis methods can be used, depending on the propulsion data available and the propeller characteristics required.

and the propeller characteristics required.

Other propeller data may be prepared in a simple format for use by the program provided that KT KQ J Other propeller data may be prepared in a simple format for use by the program provided that KT KQ J values are available.

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3.0

3.0

PROCESS

PROCESS DESCRIPTION

DESCRIPTION

The program's method of calculation is based on locating data points within a group of experimentally The program's method of calculation is based on locating data points within a group of experimentally determin

determined KT-KQ-J curves. ed KT-KQ-J curves. At the hAt the heart of the process is eart of the process is a cubic spline fitting and a cubic spline fitting and interpolationinterpolation routine, which allows cross-plotting from a known J and KT to determine the P/D ratio and KQ value. routine, which allows cross-plotting from a known J and KT to determine the P/D ratio and KQ value. By operating this procedure in ordered sequences, the program can provide a number of different By operating this procedure in ordered sequences, the program can provide a number of different approaches to the problems of design and off-design propeller calculations.

approaches to the problems of design and off-design propeller calculations.

The user is able to examine the application of various standard series propellers provided with the The user is able to examine the application of various standard series propellers provided with the  program

 program. . Each Each can can be be loadeloaded d into into the the comcomputer puter and and examexamineined d in in the the lighlight t of of the the requirequired red inputinput  parame

 parameters. Output data can theters. Output data can then be vn be viewiewed oed on the scn the screen reen or printeor printer.r.

Depending on the specific requirements, the user, having loaded propeller data, can choose one of the Depending on the specific requirements, the user, having loaded propeller data, can choose one of the design m

design methods and carry out the calculations. ethods and carry out the calculations. In eIn each case ach case the program accethe program accepts input parapts input paramemeters,ters, determines the position within the series data, and outputs the variables that were unknown.

determines the position within the series data, and outputs the variables that were unknown.

Since the curve fitting and interpolation is spline based, each point is calculated using as many data Since the curve fitting and interpolation is spline based, each point is calculated using as many data  points w

 points within thithin the che chart as possible.art as possible.

The program operates with the following full scale Propeller, Engine, and Vessel The program operates with the following full scale Propeller, Engine, and Vessel

characteristics:-Pr

Propeller opeller Engine Engine VesselVessel

 Numbe

 Number of blader of blades s NumNumber of Enber of Enginegines/Shafts s/Shafts SpeeSpeedd Diameter

Diameter Power Power per per shaft shaft ResistanceResistance

Pitch

Pitch RPM RPM Taylor Taylor Wake Wake FractFractionion

Imm

Immersion ersion Gear Gear Ratio Ratio Thrust deductionThrust deduction Blade

Blade Area Area Ratio Ratio Prop. Prop. TorqueTorque Open

Open water water efficienefficiency cy Shaft Shaft RPMRPM

Data ar

Data are presene presented in eted in either meither metric or imperial units depetric or imperial units depending nding upon preferenceupon preference. . The units areThe units are selectable within the

selectable within the program. program. The vesseThe vessel’s resistal’s resistance characteristics may ence characteristics may either be based upon ither be based upon a singlea single design speed and resistance or a table of EHP or Resistance values at different speeds

design speed and resistance or a table of EHP or Resistance values at different speeds

The first requirement is to load a set of propeller charts into memory, e.g. the Wageningen Series. The first requirement is to load a set of propeller charts into memory, e.g. the Wageningen Series. Information required for all calculations should then be set, e.g. the number of shafts which the vessel Information required for all calculations should then be set, e.g. the number of shafts which the vessel has, each being assumed to bear the same loading, and the number of blades to be assumed for the has, each being assumed to bear the same loading, and the number of blades to be assumed for the  propell

 propeller. er. The particular The particular sets of KT-KQ-J sets of KT-KQ-J data used depedata used depend upon the numnd upon the number of blades requeber of blades requested andsted and the blade area ratio, which may either be taken as a constant, or calculated against one of the standard the blade area ratio, which may either be taken as a constant, or calculated against one of the standard lines to avoid cavitation and/or thrust loss due to cavitation.

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The following methods of calculation are

available:-Input parameters Principal outputs

Design Methods

1. Diam., RPM, Speed, Resistance Pitch, Power, Efficiency

2. Diam., RPM, Speed, Power Pitch, Equivalent Resistance, Efficiency

3. Diam., Speed, Resistance Pitch, Power, Opt.RPM, Efficiency

4. Diam., Speed, Resistance Pitch, Power, Opt Gear Ratio, Efficiency

5. RPM, Speed, Resistance Pitch, Power, Opt.Diam., Efficiency

6. Diam., RPM, Power, EHP curve Pitch, Speed, Efficiency

7. Diam., Power, EHP curve Pitch, Speed, Opt.RPM, Efficiency

8. Diam., Power, EHP curve Pitch, Speed, Opt. Gear Ratio, Efficiency

9. RPM, Power, EHP curve Pitch, Speed, Opt.Diam., Efficiency

Off-design Methods:

10. Diam., Pitch, Speed, Resistance RPM, Power, Efficiency

11. Diam., Pitch, Power, EHP curve RPM, Speed, Efficiency

12. Diam., Pitch, RPM, EHP curve Power, Speed, Efficiency

13. Diam., Pitch, Torque, EHP curve RPM, Power, Speed, Efficiency

Additional Design Methods

14. Diam., Speed, Power Pitch, Opt.RPM, Efficiency

15. Diam., Speed, Power Pitch, Opt Gear Ratio, Efficiency

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4.0

GETTING STARTED

4.1 The main screen

The screen is divided into four main areas, a menu, a toolbar, a tabbed notebook and a status line:

-Menu Toolbar 

Tabbed notebook - data area

Status line - hints

The Menu allows access to a variety of commands for loading and saving data to files, editing information, printing, setting graphics options, and obtaining on-line help.

The Toolbar contains icons, which carry out the more common commands, such as loading in data. Each icon displays a ‘hint’, showing its use, when the mouse cursor is placed over it.

All of the data entry and editing, as well as the display of results, occurs in the Tabbed Notebook area, which is split into four pages. Clicking the mouse on the titled tabs, or selecting the page in the Window menu item, changes the

page:-1. Propeller page. This page contains the main data concerning the propeller, engine installation, and the vessel’s speed and resistance characteristic at the design point..

2. EHP Datapage. Allows for the entry of the vessel’s resistance over a range of speeds.

3. KT/KQpage. This page allows access to the KT/KQ/J data upon which the program’s calculations are based. The data can be viewed graphically, or individual values examined.

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4.2 A simple calculation

In this first example the most basic calculations are made at a single speed. The requirement is to determine the optimum pitch for a single screw vessel with a propeller of fixed diameter, with an engine running at a known RPM. To achieve this use calculation method 1, and assume that the propeller will  be of the Wageningen-B

type:-a) Take the File|Load Propeller Data menu option, or click on the Load Propeller icon , and load the Wageningen series into memory.

 b) Set the Calculation method to type 1.

c) Enter the following

values:-Propeller Engine Vessel

Blades 3 Shafts 1 Speed 10

Diameter 1 RPM 600 Resistance 12

Immersion 1 Gear Ratio 1 Wake fraction 0.1

BAR 0.7 Thrust deduct 0.1

d) Ensure that the Paste result to report box is checked, and then click the Calculate button. The Pitch, Efficiency, Power and Torque values are calculated and

displayed:-In this case the program shows that in order to generate a 12 kN forward force to the vessel, the  propeller will need a 0.715 metre pitch, and will absorb 112.5 kW of power.

This is the most basic form of  calculation, where all of the

 propeller’s operating

 parameters are fixed. So the resulting efficiency is unlikely to be an optimum. Before continuing look at the report  page and confirm that the results are displayed there.

The text shown may be edited, copied to the clipboard for inclusion in another document, or printed directly by choosing the File|Print option or clicking the Print icon in the toolbar 

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4.3 Optimisation

In order to see if the efficiency of the propeller calculated above can be improved the calculation can be repeated with various inputs altered manually. Alternatively one of the optimising methods can be selected, and the program will run through a range of parameter values and determine the optimum automatically.

a) Set the Calculation method to type 3.

 b) Leave the main data values as they are.

c) Ensure that the Show Graphic Result is checked, and then click the Calculate button. The variation of efficiency with RPM is shown in a

graph:-Close the graph by taking the File|Close menu option.

4.4 Calculating for a known engine

This example is the type of calculation a designer makes when there is a preferred engine option. For this calculation the designer requires the vessel to achieve its best speed, so the speed/resistance data must be entered over a speed range. Change to the EHP data page, and from the Edit|O ptions menu set the matrix of speed data to have four lines, and to accept speed resistance values by clicking the Input: Resistance Radio button. Enter data at four speeds, for the vessel’s total resistance, Wake fraction and Thrust

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deduction:- Note that as speed and resistance values are entered the program calculates the speed of advance and required thrust as well as the EHP values. It is also possible to enter speed and EHP values, in which case the resistance is calculated by the program and shown in the third column.

a) Load the Gawn series into memory by taking the File|Load Propeller Data menu option, or clicking on the Load Propeller icon .

 b) Set the Calculation method to type 6.

c) Enter the following

values:-Propeller Engine

Blades 3 Shafts 2

Diameter 1 Power 350

B.A.R. 0.7 RPM 1800

Gear Ratio 2

d) Ensure that Paste result to report is checked, calculate the result, and display the

Report:-The contents of the report page can now be printed, or copied to the clipboard for inclusion in a word processor document.

Having viewed these results the effects of optimising shaft RPM can be investigated by selecting calculation method 8, which

determines the optimum

reduction gear ratio. The result should show that reducing shaft RPM by using a 2.987:1 reduction, improves efficiency  by 10% and allows the vessel to achieve a speed of almost 24 knots.

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4.5 Checking the blade area

So far the calculations performed in this introduction have been performed without concern for  cavitation. In order to determine that the blade area is sufficient to avoid cavitation and/or thrust loss due to cavitation the program can carry out a cavitation check using one of three Burrill cavitation limit

lines:-1. A limit applicable to tugs and trawlers.

2. A limit applicable to merchant ships with aerofoil type propeller sections, leading to approximately 2% - 4% back cavitation.

3. A limit for propellers with uniform suction type sections typically used in naval vessels, fast surface craft and SES or hydrofoil craft where greater risk of cavitation is accepted. Ref K indicates that this line is just below the likely onset of thrust breakdown due to cavitation.

To do this alter the Limit Line selected in the Cavitation BAR Limit group of data fields to 3 Fast Craft, and recalculate. The resulting Required BAR shows that a 0.622 BAR would be appropriate to avoid thrust loss.

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5.0

PROGRAM REFERENCE

The program operates by means of the normal Windows screen controls and menus as well as some special features.

5.1 General controls

Menus operate in the standard Windows way. Click on a menu item, or press the appropriate hot-key option (the Alt key and underlined letter), or press theEnterkey when the menu item is highlighted, and either a further drop down menu opens, or the menu command is performed. Pressing the Alt key on its own toggles the program focus to/from the main menu line. When a drop down menu is displayed the up and down keys move through the list, otherwise use the left and right arrow keys to move between items.

The toolbar consists of various small icons, located below the main menu line. To operate a toolbar  command click the mouse button when the pointer is located over the icon. Each toolbar icon displays a hint message if the pointer is left over it for a short while.

The main area of the screen window is taken up by a Tabbed notebook , see below. The notebook is split into four pages, each containing its own set of controls. As a page is displayed the menu and toolbars change as necessary.

Within each of the notebook pages the program uses a variety of

controls:-1. Tabbed notebook. A screen control which displays multiple pages, each of which can contain other controls. Each page is identified by a tab, which contains the page name as an identifier, e.g. Propeller, EHP Data, KT/KQ and Report. To change pages click the mouse button when the pointer  is over one of the tabs. If a tab is already highlighted, i.e. the notebook itself has the program’s focus, the left and right arrows can also be used to change pages.

2. Edit box. A box on the screen which can contain a line of text. The text can be modified  by giving the box the focus, i.e. highlighting it with the mouse, or by using the tab key until the

content is highlighted.

3. Selection box. A box on the screen which contains one of a number of choices. To the right of the box is a downward pointing arrow, clicking on the arrow opens up a drop down list of the text associated with each choice. Scroll down the list and highlight the required value, then click the mouse button. The list is removed, the box content changed to show the chosen item. If the box has focus the option can also be changed using the arrow keys.

4. Check box. A small box, with associated text, used to toggle an option on or off. The state of the option is shown by the box containing a check mark,X, indicating that the option is selected, or being left blank. To change the option click the mouse button when the pointer is over the box.

5. String grid. A matrix of strings drawn in a grid. Each string occupies a cell in the grid. Cells shown in grey are not available for editing and either show headings, e.g. Speed, or calculated values. To alter a value highlight the cell by pressing the mouse button with the pointer located over  the cell position, or if a cell is already highlighted use the up, down, left or right keys to move the

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highlight to the required cell. Once the correct cell is highlighted the new value can be typed, or the old one edited.

6. List Box. List boxes, hold a set of text strings e.g. propeller chart names, which are fixed. If the number of strings is too large for the space provided then a vertical scroll bar is shown within the box and can be moved with the mouse to scroll the box contents. If the box has focus the up and down keys can move the selection to a different line, otherwise a line may be selected by  placing the mouse pointer over it and pressing the button.

7. Button. Buttons are used to initiate specific commands. To press a button locate the  pointer over the button and press the mouse button. Alternatively the Enter key will operate a  button if the button has focus, usually the button will form part of a tab sequence and will receive

focus by repetitively pressing the tab key. Buttons can also be operated with a hot-key sequence of  the Alt key and their underlined letter.

8. Memo. A memo is an area of the screen which can contain unformatted text, and can  be edited, e.g. the Report Page. Memos can contain many lines of text, with variable lengths, and

the scroll bars allow different parts of the memo to be displayed in the available space. To edit the memo, position the mouse cursor at the appropriate position, press the button, and then type or edit as required.

9. Radio Button A control which selects one out of a number of options. Clicking the mouse over an option turns the others off.

The Propeller page contains the edit boxes which are used to enter and edit the various data values required for the calculation, e.g. the diameter. The program checks to see that the characters form a valid number before calculating, if non numeric characters are found an error message is displayed and the program requests that the value is corrected. There are also selection boxes for the calculation method, units, and cavitation checks, as well as check boxes.

TheEHP Data page is taken up by a string grid. This allows for a matrix of values to be entered and edited.

The list of propeller charts which make up the loaded propeller series is shown in a list box on the KT/KQpage. As the selected propeller chart is changed then the KT/KQ/J data are shown graphically in the space to the right. Clicking the mouse button in the graphic area enlarges it.

Calculations are made using the data from the appropriate edit boxes by pressing a button such as Calculate(propeller page) or PD for KT (KT/KQ page).

The main output from the program is stored on theReport page, which consists of a memo. The memo content can be printed to file or printer, edited, cut or copied to the clipboard, or have the clipboard content pasted into it.

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5.2 Display pages

5.2.1 Propeller Page

The propeller page is used to describe the propeller geometry, the conditions in which it is operating and the design method used. There are also various output options for results. It contains the following

elements:-· Heading A general heading for the data used in the current file is entered in the

heading edit box.

· Calculation method A selection box for choosing the calculation method. The methods and

their description are detailed in the Propeller Design Guide.

· Units A selection box used to choose the units. Two different metric type units

and two different imperial type units can be selected.

· Show graphic result The show graphic result check box, if checked a graph of results is

displayed when the calculate button is pressed. The graph appears in the Output Window.

· Paste result to report The paste result to report check box, if selected, pastes the results of the

calculation to the Report Page.

· Propeller Contains all of the edit boxes required to describe a propeller. ·

· Blades The number of blades per propeller 

· Diameter The overall propeller diameter, in metres, cm, feet or inches.

· Pitch The overall pitch of the propeller, in metres, cm, feet or inches.

· Immersion The depth of the propeller hub, in metres, cm, feet or inches.

· BAR The developed blade area ratio.

· Efficiency The calculated open water efficiency.

· Engine Contains the edit boxes describing the engine/s and shaft/s.

· Shafts The number of shafts/engines in the vessel

· Power The delivered power of a single engine/shaft, in kW or HP

· RPM The engine RPM at which the power is developed

· Gear ratio The reduction ratio between the engine and propeller shaft

· Prop Torque The calculated torque in the shaft in kNm, Nm, ton.ft, lb.ft.

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· Vessel Contains the edit boxes describing the vessel’s powering.

· Speed The speed of the vessel in knots

· Resistance The vessels total resistance at the speed, in kN, N, tonf or lbf. · Equiv. Resistance The thrust generated by the propeller * (1 – thrust deduction) · Wake fraction The Taylor wake fraction, to convert ship speed to speed of 

advance

· Thrust deduction The thrust deduction factor, to convert the ship’s resistance to the

required resistance.

· Cavitation BAR Limit Contains the edit boxes for checking cavitation

· Limit line A selection box to determine the type of cavitation check 

· Required BAR The BAR required to avoid cavitation and/or thrust loss due to

cavitation, appropriate to the Burrill limit line chosen

5.2.2 EHP Data Page

The EHP Data Page is used to describe the vessel powering performance over a range of speeds and it is in the format of a spreadsheet for inputting data. Data may be input in varying formats and units are dependent upon those selected on the Propeller Page.

Each row in the spreadsheet contains data for a ship speed in knots, either vessel resistance, in kN, N, tonf or lbf, or vessel EHP, in kW or HP, wake fraction (Wt) and thrust deduction factor (t).

5.2.3 KT/KQ Page

The KT/KQ Page provides a means of loading, displaying and looking up the propeller performance charts. It contains the following

elements:-· Series list box Displays the list of available data for a specific propeller file.

· Propeller Graph Displays the selected propeller from the propeller series list box. To

enlarge the graph click on it with the left mouse button and to restore the KT/KQ Page click on the graph again.

· Edit boxes The KT, J, P/D, KQ and Eta edit boxes are parameters used when looking

up the selected propeller chart from the propeller series list box.

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5.2.4 Report Page

The report page is a means of viewing and printing the Propeller Design Program results. It can be edited and written to like a word processor. If the Paste to report check box is checked, the results are  pasted to it every time the Calculate button is pressed on the Propeller Page.

Text can be cut and copied from the report page to the clipboard and also pasted from the clipboard.

5.2.5 Output Window

The output window is a means of viewing and printing the results graphically from a multi point calculation from the design method selected on the Propeller Page, it is activated when the Calculate  button is pressed and the Show Graphic Result check box is checked on the Propeller Page. The output

graph can be altered using the File|Plot Options command on the window’s menu bar.

5.3 Dialog boxes 5.3.1 About Dialog

The About Dialog indicates the Propeller Design Program version. Click on the dialog to close it. 5.3.2 EHP Options Dialog

The EHP Options Dialog is used to set up the way in which data are input into the EHP Page and the number of lines of input. The following controls are

displayed:-· Number of lines An edit box which specifies the total number of lines on the EHP Page for 

input of data.

· Resistance/EHP

radio buttons

Specify the way in which data are input either by total resistance or  effective power. This can also be set by using the Swap RES/EHP command on the Edit menu of the EHP Page.

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5.3.3 Plot Options Dialog

The Plot Options Dialog is used to set-up the way in which graph plots are presented on the KT/KQ Page and Output Window. It contains the following

controls:-· Font button Used to specify the font on the particular graph plot. The font button

activates the standard Font Dialog.

· Margin edit box Sets the margin on the page around the graph plot as a percentage of the

width.

· Tick length edit box Sets the tick length on the axes as a percentage of the total graph plot size.

· X & Y Squares These edit boxes set the maximum number of ticks along the x-axis and

y-axis respectively.

· OK button Closes the dialog and effects the changes.

5.3.3 Paste from Clipboard Dialog

The Paste from Clipboard Dialog displays the content of the clipboard in a memo area, which can be edited if required, before allowing it to be pasted into the EHP Page.

Data must consist of two columns of numbers, and the EHP page must be prepared with the correct units and Resistance/EHP column option. The paste operation will ignore lines which do not contain at least two numeric values, or which start with non-numeric text.

The OK button closes the dialog and effects the changes if the data are valid, the Cancel button closes the dialog and no changes are made.

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5.4 Menus All Pages

File Menu Window Menu Help menu

 New Run Power Prediction Contents

Open Propeller Topic search

Save EHP How to use help

Save as KT/KQ About

History list Report

Exit Toolbar 

All Pages|File Menu

· New Creates a new blank set of data. If a propeller file already exists in the

 program and changes have occurred 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 New Button on the File Toolbar.

· Open Activates the Open Dialog to load a new propeller into the program. If a

file already exists in the program and changes have occurred a prompt will appear asking to save changes to the current working file. This command can also be accessed via the Open Button on the File Toolbar.

· Save The Save command stores the propeller to file. If the file has not been

saved before the command activates the Save Dialog and prompts the user  for a file name. This command can also be accessed via the Save Button on the File Toolbar.

· Save As The Save As command stores the propeller to a file. The command

activates the Save As Dialog and prompts the user for a file name.

· History list The last four accessed or saved propeller design files are displayed here,

and can be loaded by clicking on the appropriate name.

· Exit The Exit command quits the program. If a file already exists in the

 program and changes have occurred a save prompt will appear.

All pages|Window menu

· Run Power Predic’n Runs the Windows version of Power Prediction.

· Propeller Changes to the Propeller Page.

· EHP Changes to the EHP Data Page.

· KT/KQ Changes to the KT/KQ Page.

· Report Changes to the Report Page.

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All pages|Help menu

· Contents The Contents command activates help at the index page.

· Topic Search The Topic Search command activates the help topic search.

· How to use Activates Windows ‘How to Use Help’ function.

· About The About command activates the About Dialog.

Menu commands for specific pages are shown

here:-Propeller Page

File Menu Calc

Load Propeller data Load EHP data

Propeller page|File menu

· Load Propeller data The Load Propeller command loads a set of propeller charts. The

command activates the Open Dialog.

· Load EHP The Load EHP command loads an EHP curve into the Propeller Design

Program. The command activates the Open Dialog.

Propeller page|Calc menu

· Calc Run the calculation as set on the page.

EHP Data Page (There is also a popup menu which is activated by the right mouse button.)

File Menu Edit Menu & Popup Menu

Load EHP data Sort

Save EHP data Insert Line

Delete Line Copy to Report Paste from Clipboard Swap Res/EHP Set Wt

Set t Options

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EHP Data Page|Edit menu

· Sort The Sort command sorts the list of data on the EHP Data Page into

numerical order according to the speed column.

· Insert Line The Insert Line command insert a blank line above the line that currently

has the focus on the EHP Data Page.

· Delete Line The Delete Line command deletes the line that currently has the focus on

the EHP Data Page.

· Copy to Report The Copy to Report command copies the contents of the EHP Data Page

to the Report Page in the form of a text table.

· Paste from Clipboard Allows entry of Speed/Resistance or Speed/EHP data from values pasted

to the clipboard by other applications. The EHP Data Page must be set to allow editing of data in the correct column and the units must be selected appropriately. The Clipboard is displayed in a dialog. If it looks correct, i.e. a table containing Speed and EHP/Resistance values, pressing OK will reset the EHP Data Page to the new values. Wake and thrust deductions can then be set. Cancel leaves the data as they were. The operation parses data to exclude lines which do not contain at least two real numbers or  which contain other text characters

· Swap RES/EHP The Swap RES/EHP command swaps the resistance and EHP column on

the EHP Data Page such that resistance data can be input instead of EHP data.

· Set Wt The Set Wt command sets all the values in the Wt column to the currently

selected Wt value on the EHP Data Page.

· Set t The Set t command sets all the values in the t column to the currently

selected t value on the EHP Data Page.

· Options The Options command activates the Options Dialog.

KT/KQ Page File Menu

Load Propeller data Plot Options

KT/KQ Page|File Menu

· Load Propeller data The Load Propeller command loads a set of propeller charts. The

command activates the Open Dialog.

· Plot Options The Plot Options command activates the Plot Option Dialog, allowing

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Report Page

File Menu Edit menu

Load Report Font

Save Report Cut

Print Clear 

Print Setup Copy

Paste

Report Page|File Menu

· Load Report The Load report loads an ASCII text file into the report, deleting the

existing text. Any text file can be loaded into the report page. The command activates the Open Dialog.

· Save Report The Save report saves the current report to an ASCII text file. The

command activates the Save Dialog.

· Print The Print command prints the report. The command activates the Print

Dialog. This command can also be accessed via the print file button on the File Toolbar 

· Print Setup The Print Setup command activates the Print Setup Dialog.

Report Page|Edit Menu

· Font The font command activates the Font Dialog. The font chosen in the dialog

then becomes the font that is presented in the Report Page only Fixed Pitch fonts may be selected

· Cut The Cut command cuts the current text selection from the Report Page to

the clipboard.

· Clear The Clear command clears all the selected text in the Report Page.

· Copy The Copy command copies the current text selection from the Report Page

to the clipboard.

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Output Window File Menu Plot Options Print Setup Print Close

Output Window|File Menu

· Printer Setup The Printer Setup command activates the Printer Setup dialog.

· Print The Print command activates the Print dialog.

· Plot Options The plot options command activates the Plot Option Dialog

· Close The Close command closes the Output Window.

5.5 The Toolbar All Pages

 New Open Save

Run Power Prediction Load Propeller 

Load EHP Data Calculate

About

The toolbar icons change depending upon the current notebook page that is selected. Icons that are available to all pages are listed

below:-· New Operates the New menu option to clear all data.

· Open Operates the Open menu option to load a new propeller file.

· Save Operates the Save menu option to save the current data to a propeller file.

· Run Power

Prediction

Initiates a copy of the Power Prediction Program. This feature only works if you have a copy of the Windows version of Power Prediction. This allows you to run a prediction and transfer the resulting Resistance data into the Propeller program via the clipboard. Once a resistance calculation has been performed use the Paste to Clipboard option from the results  pages, then revert to the Propeller Design program and use the EHP Data

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· Load Propeller Operates the Load Propeller menu option to load a new set of propeller 

KT/KQ/J charts into the program.

· Load EHP Data Operates the Load EHP menu option to load a new set of EHP/Resistance

data into the program.

§ Calculate Runs a calculation using the data as set.

· About Operates the About Dialog.

Icons available in the report page are shown

here:-Report Page Print

Report Font Cut

Copy

· Print Operates the Print menu option to print the contents of the Report Page to

a printer.

· A Report Font Operates the Font menu option to change the font of the Report Page

output. The program only allows fixed pitch fonts.

· Cut Operates the Cut menu option to remove any selected text from the Report

Page and place it in the clipboard.

· Copy Operates the Copy menu option to copy any selected text from the Report

Page to the clipboard.

· Paste Operates the Paste menu option to paste the contents of the clipboard to

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6.0

PROPELLER DESIGN GUIDE

In order for the user to obtain the maximum benefit from this package, this section describes the nomenclature used within the manual, the various design methods, special design cases, and some approximate values for wake fraction and thrust deduction factor.

6.1 Nomenclature

D Propeller diameter 

BAR Blade area ratio

DHP Delivered power 

 N Revolutions per minute

n Revolutions per second

P Pitch

PD Pitch diameter ratio

Vs Ship speed (knots)

Va Speed of Advance Vs*(1-Wt) (knots)

v Speed of advance (metres/sec)

J Advance coefficient v/nD

R Total resistance of vessel

T Required thrust R/(1-t)

Q Torque

r Water density (SG 1.025)

KT Thrust coefficient R/r*n^2*D^4

KQ Torque coefficient Q/r*n^2*D^5

eo Open water efficiency

eh Hull efficiency

er Relative rotative efficiency

Wt Wake fraction

t Thrust deduction factor 

CB Block coefficient

LB Length/Beam ratio

Fn Froude number 

Fv Volume Froude number 

L Waterline length

QPC Quasi propulsive coefficient

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6.2 Design Methods

1. This method assumes that D,N,R and Vs are all known, thus defining a single point within the  propeller data. The corresponding pitch, open water efficiency and delivered power are

determined. The design methods (3-8) use this method repeatedly to perform their iterations.

2. This method is an alternative to method 1. It allows you to specify an engine installation i.e. DHP and N for a propeller of fixed diameter, and for the appropriate speed of advance will calculate the  pitch and thrust delivered.

3. Using a fixed propeller diameter, at a known speed of advance and thrust requirement, this method determines the optimum propeller revolutions and pitch, by determining the maximum open water  efficiency.

4. Using a fixed propeller diameter, at a known speed of advance and thrust requirement, this method determines the optimum propeller revolutions, and with fixed engine RPM the optimum gear ration and pitch, by determining the maximum open water efficiency.

5. This method is similar to method 3, but determines the optimum propeller diameter for fixed revolutions.

6. A known delivered power is required to be absorbed by a propeller whose diameter and revolutions are fixed. (This might correspond to a medium or high speed diesel with a specified gear ratio or a direct drive large bore diesel, with a propeller aperture or draught limitation). Also input are data relating thrust to speed of advance, derived from tank test or from published results. The speed/thrust point at which the DHP is fully absorbed is calculated.

7. This method repeats method 6, except that no RPM value is input. It calculates the resulting speed/thrust point for full power absorption, and the corresponding optimum RPM and pitch.

8. This method repeats method 7,but determines the optimum gear ratio for a fixed engine RPM.

9. This method repeats method 6 except that no diameter is input. It calculates the resulting speed/thrust point for full power absorption and the corresponding optimum diameter and pitch.

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6.3 Off-Design Methods

10. A basic off-design calculation, where the speed of advance and thrust for a propeller of known diameter and pitch are input. The RPM and delivered power are obtained.

11. For a propeller of given diameter and pitch, the method calculates, from a specified set of speed of  advance/thrust points, the resulting speed of advance and the RPM required fully to absorb a given  power.

12. For a propeller of given diameter, pitch and RPM this method calculates, for a set of speed/thrust data, the resulting speed of advance and delivered power (e.g. investigating performance with an RPM limit).

13. This method is similar to method 11 except that a torque limit is set rather than a DHP requirement.

6.4 Additional Design Methods

14. Using a fixed propeller diameter, at a known vessel speed and engine power, this method determines the optimum propeller revolutions and pitch, by determining the maximum open water  efficiency.

15. Using a fixed propeller diameter, at a known vessel speed and engine power, this method determines the optimum propeller revolutions, and with fixed engine RPM the optimum gear ration and pitch, by determining the maximum open water efficiency.

16. This method is similar to method 14, but determines the optimum propeller diameter for fixed revolutions.

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6.5 Special Design Methods

The program allows several different approaches to the problems of propeller design, which should cover most applications directly. Two special cases, bollard pull and towing, require repeated use of  the design methods and recommendations are given here to help obtain the results rapidly. Also included in this section are further considerations of the cavitation check method.

Bollard pull design

a) DHP and N for a required

T:-Repeated use of Method 1 is recommended. For a given D, T and Vs = 0, assume a range of N and obtain DHP values to find a minimum. Similarly torque can be monitored over the range.

B) T for a given DHP or

Q:-Repeated use of Method 1 is recommended. Given D and Vs = 0, assume a range of T. For each T take a range of N values as in (a) and determine the minimum DHP or Q at each T. Thus T can be determined for the actual DHP or Q.

If N is given (say for a CP propeller) assume a range of T until the desired DHP or Q is obtained.

c) The influence of diameter would be investigated by repeating the above calculations for a range of  diameters.

Towing or bollard pull off-design

Repeated use of Method 10 is recommended. Given D, P/D and Vs (Vs = 0 for the bollard case), examine a range of T values until the required DHP or Q is achieved.

Cavitation check 

Cavitation checks are specified by selecting the appropriate limit line from the drop-down list. The  program carries out an approximate cavitation check using a Burrill cavitation limit line, in order to

determine the minimum BAR required to avoid cavitation and/or thrust loss due to cavitation.

The primary object of the cavitation check is to ensure that the correct propeller chart data are used in the design calculations. For example, an initial design estimate, using an assumed BAR, will provide the input information necessary to carry out a preliminary cavitation/BAR check and thus choose the most suitable design chart for further calculations. Three limit lines are available corresponding to Ref 

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J-If the calculated minimum BAR is greater than the maximum BAR of the propeller chart data, then the  program should be run with the appropriate BAR Set value.

6.6 Wake Fraction and Thrust Deduction Factor

The design methods require the estimation

of:-a) Propeller speed of advance Va = Vs*(1-Wt)

 b) Required thrust, T = R/(1-t) where R is hull resistance and t the thrust deduction factor.

 Normally hull resistance will be estimated from model tests or published data. Some empirical values of Wt and t, suitable for design purposes, are given in this section. For completeness, the program outputs of torque and delivered power should be divided by the relative rotative efficiency (er) which normally lies within the range 0.95-1.05 and is often taken as unity for preliminary design calculations. Data showing the influence of hull parameters are given in Refs F and G

Merchant Ship Forms Single Screw

Wake fraction

estimates:-Wt = 0.54*CB - .08

Wt = (1.095 - 3.4*CB + 3.3*CB^2) + (0.5*CB^2*(6.5 - LB)/LB) CB = Block Coefficient LB = Length/Beam ratio

Range of application : CB 0.525-0.75 LB 5-8 See also Ref A.

Thrust deduction and rotative efficiency

estimates:-t = 0.23*CB + 0.05

er = 1.716 - 2.378*CB + 1.74*CB*Vs/L^.5 + 0.6931*D/Vol^.333 Vol = Volume in m^3

Range of application : CB 0.65-0.8 See also Refs B and C

Twin Screw

Wake fraction

estimates:-Wt = 0.55*CB - 0.2

Wt = (0.71 - 2.39*CB + 2.33*CB^2) + (0.12*CB^4*(6.5 - LB)) Range of application : CB 0.525-0.675 LB 6-7

Thrust deduction

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High Speed Round Bilge Craft

Typical values may be found in Ref D. Data presented here are for hull forms similar to the NPL round  bilge with twin screws.

Wake fraction, thrust deduction and rotative efficiency

estimates:-Fv Wt t er  ---0.6 0 0.12 0.95 1.4 -0.04 0.07 0.95 CB range from 0.37-0.45 2.6 0 0.08 0.95 ---0.6 0.08 0.15 1.07 1.4 -0.02 0.07 0.95 CB range from 0.45-0.52 2.2 0.04 0.06 0.96

---Range of application : Fv 0.58-2.76. Fv = Volume Froude number and is 0.165*Vs/Disp^0.1667

Vs is in knots Disp is in tonnes. Data showing the influence of shaft angle on t and regression equations for Wt, t, and er are presented in Ref D.

Trawler Forms

Typical values are presented in Ref E.

Wake fraction, thrust deduction and rotative efficiency

estimates:-CB Wt t er  ---0.53 0.153 0.195 1.048 0.57 0.178 0.2 1.043 Fn range from 0.29-0.33 0.6 0.2 0.23 1.03

---Fn = Froude number and is 0.1643*Vs/L^0.5 Vs is in knots

L is in metres

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Tug Forms

Typical values are presented in Refs F and G

Wake fraction, thrust deduction and rotative efficiency

estimates:-Fn Wt t er  ---0.34 0.21 0.23 1.02 Free running 0.21 - 0.12 -0.15 - 0.1 - Towing For CB = 0.503 0.09 - 0.07 -0 - 0.02 - Bollard ---0.36 0.2 0.25 1.01 Free running 0.21 0.2 0.15 1.03 0.12 0.25 0.12 1.02 Towing For CB = 0.575 0 - 0.07 - Bollard ---Range of application : Fn 0 - 0.36

In all the above data the values presented are approximate only. Individual components of propulsive efficiency will depend on the detailed hull and propeller characteristics of that application. More information can be found in the References. If necessary, the calculations in the program may be run over a range of Wt and t values, to assess their sensitivity to these factors.

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7.0

GLOSSARY

Blade Area Ratio BAR 

The ratio of developed blade area to the disc area.

Cavitation Check 

A calculation, using empirical data based upon the Burrill cavitation lines (see references), to determine a suitable BAR.

Delivered Power

The power delivered to the propeller.

DHP = EHP/QPC = R*Vs/(eo*eh*er)

where EHP = Effective power to propel hull = R*Vs R = Total hull resistance

QPC = Quasi propulsive coefficient = eo*eh*er  eo = Open water efficiency

eh = Hull efficiency = R*Vs/T*Va = (1-t)/(1-Wt)

er = Relative rotative efficiency, accounting for the differences in the flow pattern behind the hull and in open water 

The program outputs DHP based on Q, the open water torque value. For completeness the output values of DHP and Q should be divided by er.

Error Messages

Screen output showing where the calculation process failed, or went out of range.

Gawn Series

A standard series of three bladed propellers tested at AMTE (Haslar) by R W L Gawn. See references.

Immersion

The depth below the water surface of the propeller centreline.

J

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KT

A non-dimensional thrust coefficient = (T’/r*n^2*D^4). See nomenclature.

Open Water Efficiency

Efficiency of a propeller in open water without the influence of a hull. eo = T’*Va/(2*PI*n*Q)

P/D

The ratio of propeller pitch to diameter.

Pitch

The distance a propeller progresses during one revolution, assuming no slip.

Speed of Advance

Due to the influence of the hull, the average flow speed (Va) into the propeller is different from (usually less than) the ship speed, and Va = Vs*(1-Wt) where Vs is the ship speed and Wt the wake fraction.

Standard Series Propellers

A group of propellers of similar geometric shapes, which have been tested in water tunnels or tanks to determine their characteristics. The program is supplied with Gawn, Wageningen B and Kaplan series data.

Thrust Deduction Factor t

Due to the action of the propeller, the hull resistance will be increased. The thrust required will be T’ = T/(1-t).

Wageningen B Series

A standard series of propellers, originally tested by L Troost at the NSMB Wageningen.

Wake Fraction Wt (Taylor)

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8.0

ERROR MESSAGES

Errors are displayed in a message box,

e.g.:-The box describes the type of error. To continue operation the OK button must be clicked. 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, usually because its value is zero.

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Data boundary errors

Data boundary errors occur when the program finds that the input values set fall outside the boundaries of possible solutions. There are two boundaries that the program checks.

1. The propeller data, i.e. the KT/KQ/J values. The message shown here indicates that at the value of J for which the program is calculating the KT value lies below the data for the lowest P/D curve. The  program does not extrapolate beyond the boundary.

2. The EHP/Resistance data may not cover a sufficient range of speed for calculation to proceed. Where this results in calculated powers or resistances less than those found in the EHP Data Page the message reads ‘Speed Range Too High’, where the calculated data are greater than those in the EHP data the message reads ‘Speed Range Too Low’.

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, or because the file name or path is invalid.

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APPENDIX I

REFERENCES

1. General Propeller Design and Propulsion Data

 A) O'BRIEN T P, The design of marine screw propellers Hutchinson

B) PARKER M N, The BSRA Methodical Series - An overall presentation Propulsion factors, Trans RINA vol 108 1966

C) PATULLO R N M and WRIGHT B D W, Methodical series experiments on single screw merchant

ship forms; extended and revised overall analysis, BSRA Report No NS 333 1971

D) BAILEY D, A statistical analysis of propulsion data from models of high speed round bilge hulls, Proc Symposium of Fast Warships and Security Vessels

E) PATULLO R N M and THOMPSON G R, The BSRA Trawler Series I-III, Trans RINA vol 107 1965, vol 110 1968, vol III 1969

F) PARKER M N and DAWSON J, Tug propulsion investigation, Trans RINA vol 104 1962

G) MOOR D O, An investigation of tug propulsion, Trans RINA vol 105 1963 2. Standard Series Data

H) TROOST L, Open water tests with modern propeller forms, Trans NEC Inst of E & S vol 67 1950/1

I) GAWN R W L, Effect of pitch and blade width on propeller performance, Trans RINA vol 95 1953 3. Cavitation Series

J) BURRILL L C, Aerodynamics and marine propeller design, Trans NEC Inst of E & S vol 81 1964/5

K) GAWN R W L and BURRILL L C, Effect of cavitation on the performance of a series of 16 inch  propellers, Trans RINA vol 99 1957

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APPENDIX II

FILE FORMATS

The program uses three types of file:

Propeller Files Propeller Data Files EHP Data Files

Propeller Files *.PDD

The main file type used in the program stores all of the data from the main Propeller Page, the EHP Data Page and the names of other files used. Each item in the file is prefaced by its meaning followed  by a colon. A typical file looks

like:-Wolfson Unit Propeller Data Title:Southampton Dockyard Calc type:6 Cavitation type:2 Units:1 Show graph:0 Paste result:0 Blades:4 Diameter:1 Pitch:0.921 Immersion:0.000 BAR:0.862 Efficiency:58.24 Engine Power:194.97 Engine RPM:600 Gear Ratio:1 Shafts:1 Shaft Torque:3.103 Shaft RPM:600.00 Speed:11.11 Thrust:18.178 Wake fraction:-0.023 Thrust deduction:0.064 EHP data:6 EHP focus:0 10.17 13.154 12.22 10 62.864 -0.017 0.071 12.34 24.257 22.85 12 141.053 -0.028 0.058 14.52 39.188 37.15 14 267.525 -0.037 0.052 16.66 45.042 42.79 16 352.166 -0.041 0.05 18.74 49.159 46.75 18 432.837 -0.041 0.049 20.74 51.849 49.36 20 507.789 -0.037 0.048 Propeller series:C:\RES\WINPROP\WAGENING.WUP EHP datafile:C:\RES\WINPROP\TEST2.PPG Report file:

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Propeller Data *.WUP

Propeller data files contain the KT/KQ/J values with which the program works. A list of all the files  provided with the program is given in the Standard Series Data. Users can build up further files,  provided that they have access to KT/KQ/J values from test results, by creating text files of the correct

format.

The files are formatted as

follows:-Line 1 7 Gawn Series The number of KT/KQ/J data sets in the file, and a descriptor  Line 2 3 The number of blades in the first data set

Line 3 0.20 The Blade Area Ratio of the first set. Line 4 23 The number of J values in the first set Line 5 9 The number of P/D ratios in the first set

Line 6 0.000 0.400 0.600 .. The P/D values, note that the first number, 0.000, does not correspond to a P/D but must be present

Line 7 0.000 0.15200 0.01060... The first number is the value of J, followed

 by the corresponding KT and KQ for each P/D. For this  propeller there will be 9 KT/KQ values on each lin e

The sequence continues for each of the J values, e.g. 23 lines as line 7 above in this case, and then the Lines 2 onwards are repeated for each data set.

 Note:

1. Each KT curve must end at zero, thus a value of J must be set where the KT curve for the P/D  becomes zero, and KT/KQ data will therefore be read in for all P/D’s in the set at that J.

2. Where a KT or KQ curve ends then all subsequent values must be set to zero

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There are two blade sets, a 3 bladed 0.65 BAR and a 4 bladed 0.55 BAR. The first blade set contains values at 9 J values, and the second has 10 J values. In each case data are only presented at Pitch/Diameter rations of 0.6 and 0.8. As an example, the KT for a J of 0.4 and a P/D of 0.8 for the 3  bladed propeller is 0.175, and the corresponding KQ is 0.0208. Since WUP files are ASCII formatted they may be examined, edited or created with any Word Processor or Editor or Spreadsheet program capable of storing ASCII files.

2 Small series 3 0.65 9 2 0.000 0.600 0.800 0.000 0.23100 0.01500 0.36400 0.02590 0.100 0.19800 0.01470 0.31700 0.02560 0.200 0.15400 0.01370 0.27100 0.02460 0.300 0.11200 0.01280 0.22600 0.02320 0.400 0.06800 0.01030 0.17500 0.02080 0.516 0.00000 0.00700 0.11200 0.01740 0.600 0.00000 0.00400 0.05400 0.01380 0.673 0.00000 0.00000 0.00000 0.01040 0.750 0.00000 0.00000 0.00000 0.00600 4 0.55 10 2 0.000 0.600 0.800 0.000 0.23900 0.01570 0.36500 0.02840 0.100 0.19900 0.01510 0.31700 0.02710 0.200 0.16200 0.01440 0.27500 0.02590 0.300 0.12600 0.01330 0.23200 0.02440 0.400 0.08200 0.01140 0.18600 0.02250 0.534 0.00000 0.00790 0.11200 0.01830 0.600 0.00000 0.00570 0.06900 0.01560 0.681 0.00000 0.00270 0.00000 0.01190 0.750 0.00000 0.00000 0.00000 0.00870 0.845 0.00000 0.00000 0.00000 0.00370

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EHP Data *.PPG

The EHP data file type stores the values of Speed, EHP/Resistance, Wt, and t shown in the EHP Data Page . The file format is compatible with the output from the Wolfson Unit Power Prediction Program.

The first line contains a descriptor, followed by two lines describing the content and units of the first two columns. Column 1 must be speed in knots. Column 2 may be either EHP, in ‘kW’ or ‘hp’, or  Resistance in ‘kN’ or ‘tonf’. The fourth line contains the number 1, and the fifth contains a descriptor, however this program ignores data on this line, but they must be present for compatibility with the Power Prediction program. Line 6 contains the number of speeds present in the data, and subsequent lines contain; Speed, EHP or Resistance (depending upon line 3), Wake Fraction and Thrust Deduction.  Note that older versions of Power Prediction do not include the last two columns of data when saving

.PPG files so these may be omitted if required. A typical file with EHP values, saved from the Propeller Design program looks

like:-Southampton Dockyard Speed - kts Power - kW 1 Base data 6 10 62.864 -0.017 0.071 12 141.053 -0.028 0.058 14 267.525 -0.037 0.052 16 352.166 -0.041 0.05 18 432.837 -0.041 0.049 20 507.789 -0.037 0.048

A file saved from the Power Prediction program, with Resistance values looks like

:-A test Speed - kts Resistance - kN 2 Basis Ship 10 20.000 33.820 -0.034 0.063 21.000 35.207 -0.029 0.064 22.000 36.568 -0.024 0.067 23.000 38.104 -0.019 0.073 24.000 39.605 -0.013 0.082

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INDEX

A

About Dialog...13

B Blade Area Ratio...11, 28 Blades...11 Bollard pull...24 Button...10 C Calculation method...11 Cavitation check ... 11, 24, 28 Check box...9

Configuring the system ...1

Contents... ii D Delivered Power ...28 Design Methods...22, 23 Diameter ...11 Dongle...i E Edit box...9 Efficiency...11

EHP Data page... 4, 10, 12 EHP Options Dialog...13

Engine data...11 Error messages...30 F FILE FORMATS...33 G Gawn Series...28 Gear ratio...11 Getting started...4 Glossary...28 H Heading...11 I Immersion...11, 28 Introduction...1 J J ...28 K  KQ... 28 KT... 29 KT/KQ page...4, 10, 12 L List Box... 10 M Memo... 10 Menu... 4 Menus... 15 N  Networks... i  Nomenclature... 21 O Off-Design Methods... 23

Open Water Efficiency... 29

Output Window... 13

P PD... 29

Paste from Clipboard Dialog... 14

Paste result to report... 11

Pitch...11, 29 Plot Options Dialog... 14

Power ... 11

Process description... 2

Program reference... 9

Propeller data... 11

Propeller design guide... 21

Propeller Graph... 12 Propeller page...4, 10, 11 R  REFERENCES... 32 Report page...4, 10, 13 RPM... 11 S Selection box... 9

Series list box... 12

Shaft RPM... 11

Shafts... 11

Show graphic result... 11

Special Design Methods... 24

Speed... 12

Figure

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References

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