SPManual_SPAN-Maxsurf_user manual
Contents
1. AGS SBMAX FGS Perspective view The rendering toolbar can be used to switch rendering on off and adjust light settings See the Maxsurf manual for more information Page 9 Chapter 2 Using Span Page 10 Chapter 2 Using Span Measurement File Saving a Measurement File Once you have entered the required data it is a good idea to save your work This may be done by selecting Save Measurement Data from the File menu This will overwrite the original file If you wish to save the new data with a new file name select Save Measurement Data As from the File menu and type in a new file name Opening a Measurement File Once you have saved measurement data these may be read back into SPAN using the File Open command This will read in the rig and mizzen data if you do not have a Maxsurf file open in SPAN the hull data will also be read in automatically If however you have a Maxsurf file open in SPAN you will be asked if you want to close the design If you choose yes the hull data will be loaded as well as the rig data and the Maxsurf file closed if you choose no the hull data will not be loaded from the file and you will be left with the original hull measurements This is to facilitate analysis of the same hull with different sail sets or to preform analysis on a hullform which has been modified J Close existing design 1 Prompt when opening a2. 29 Results Table 16 Rig Data eat ee 7 23 Rig Measurement Definitions 28 Rag Sketch unsere 9 Righting moment per 21 Righting Moment Crew sess 30 Righting Moment Hull 30 Righting Moments per Degree 27 de Tees 27 20 2 27 qu EE 27 S Sailing Trim a an ede 27 Save Measurement 20 Save Measurement Data 20 SBMAJ xen 12 14 26 Set Home View 21 Shrink 21 A der eed 30 SR ee en A ses 28 SMW oait ee 28 Solve Menu 22 Solve Multiple Angles 22 Span Help ettet ets 24 Spinnaker tene een tei tee 29 Nu 28 Status Ba ame 22 Surfaces trimmed sess 14 T Tile Horizontal 24 Tile Vertical 24 DA tice dd EE 29 19 22 U Undo 21 LG 23 Upright Resistance 24 Upright Resistance Graph 16 V A i orea nAn ete 29 is o de 29 ilti eiie 12 26 View 21 View Toolbar 19 MM O a a 30 jug E 26 W Wind Data stunt re 23 Wind settings 0 0 8 Wind perdia sta 22 Wi
3. 27 MS M8 en E 27 Mainsail Definitions 29 Mast Definitions eee 29 MBM ina 27 MDE Mitad 29 MODE 2 aie cunt SAE E mis 29 MDR An 29 29 Measure Hull 23 Measurement File 11 Measurement File 11 Measurement File saving 11 Measurement Trim 27 Measuring a Maxsurf 12 MENUS eene eene nnne enne 20 29 MGU en DE 29 Mizzen 8 23 Mizzen Definitions 29 Model checking sess 13 N New Measurement 20 Nomenclature 26 Notation aa ish ir 26 O Open Design 20 Open Measurement 20 Opening a Measurement File 6 P P 29 Page retento un dre 20 en RU 21 AA eae a 21 Bee 29 Performance Data 24 Performance Data Calculating 15 Perspective 24 se ee es 13 27 Planet nase 24 Plot Options 16 22 Polar Graph 16 24 Print ei seen enge 20 Profile reste e 24 Ran Sende 29 R gt 20 RER SN men nee 30 Results Data Definitions
4. 21 Contour Toolbar 19 CONTOURS isi aka 22 21 Course angles eese ctio teet 22 Crew Weight Limit 27 A 21 27 D D 27 Data Mer iiiter ante 22 27 IR ERES 27 Display Menu 22 Drag Fottmn tr tinet an 30 Drag Induced eret trenta 30 DW nain ds 26 E E 29 dan et ct 29 c 29 AA siveet 13 27 Edit Menu 21 Entering Data 7 Bttor Force 5 3252 30 Error Moment 30 IDA RC 20 ldem 29 F EA oU UO UH SEE 14 una 26 14 FEM ER 26 lue m 14 26 File Menu 20 File Toolbar 19 jr 30 Fotolia 22 Foretriangle Definitions 28 Forward Force 30 26 Getting Started seen 6 H US occa st 29 Heel Angles estet rtt eret here 30 Heeling Moment Aero 30 Heeling Moment Hydro 30 Help Men 24 Home View 21 7 23 Hull Input Parameters esses 13 Hull Measurement Definitions 26 Hull parameters 26 required values 13 Hull Speed 30 Hull surface 14 I I 28 IMS eunte tte e eee 26 J J 28 L L 27 28
5. Flat Form Drag Ind Drag Aero Heel Moment Hydro Heel Moment Hull Right Moment Crew Right Moment Force Err Moment Err Back to Results Table Speed of yacht Velocity made good to windward ve leeward ve Equilibrium heel angle of yacht Drive force produced by sails Side force produced by sails IMS Reef parameter a value of less that 1 00 indicates that the optimum sail size is less than the total available sail area IMS Flat parameter a value of less than 1 00 indicates that sail coefficients less than the maximum available are opt mum Main drag of hull and appendages Induced drag of appendages Heeling moment due to sails Heeling moment due to appendages Righting moment due to hull weight Righting moment due to crew weight The VPP algorithm balances the forward drive force against the hull drag After the maximum number of iterations any error is given here As above but for the heeling righting moment balance Chapter 4 Theoretical Reference Bibliography The interested reader may enjoy the following articles which describe some of the concepts behind SPAN and velocity prediction programs in general Gerritsma J Keuning J A and Onnink The Delft Systematic Series II experiments International Ship Building Progress vol 28 no 328 1981 Gerritsma J Onnink R and Versluis A Geometry resistance and stability of the Delft Systematic Yacht Hull Series 10th
6. Resistance Display s a graph of the upright hull resistance against hull speed Help Menu Provides access to Span Help Span Help Launches the Span manual About Span Displays information about the current version of Span you are using Chapter 4 Theoretical Reference Chapter 4 Theoretical Reference This chapter contains a list of key words and abbreviations used in this manual and provides a literature list for the interested reader Nomenclature e Bibliography Page 25 Chapter 4 Theoretical Reference Nomenclature This nomenclature describes the key words and abbreviations used in this manual IMS International Measurement System VPP Velocity Prediction Program computer program which normally balances the sail thrust against the hull drag the sail sideforce against the appendage sideforce and the heeling moment against the hull and crew righting moment in order to predict the yacht speed for a given true wind speed and course These results are normally presented in a series of polar graphs Hull Measurement Definitions Span uses the IMS nomenclature for its measurements All measurements are taken from the position of the headstay base which IMS assumes to be at the FGS position AGS SBMAX FGS For a more detailed discussion of the hull parameters calculated by SPAN interested readers are referred to A IMS an Almost Ideal Measurement System by Da
7. the corresponding window come to the front Perspective Plan Profile Body Plan Data Window Results Window Graph Window Page 19 Chapter 3 Span Reference Page 20 Menus Span uses the standard set of menu commands for File Edit and Window operations It also has a range of menus for inputting the design data completing the analysis and control of data and view displays File Menu The File menu contains commands for opening and saving files and printing Open Design Span can measure a Maxsurf design to determine the hull parameters necessary for the VPP calculations Select Open Design to open an existing Maxsurf design Close Design Select Close Design when you wish to finish with the current Maxsurf design New Measurement Data Selecting New Measurement Data will delete the existing hull and rig data from memory New data may then be entered manually loaded from a file or measured from a Maxsurf design file Open Measurement Data Span has the ability to save measurement data to disk and recall them at a later date By selecting Open Measurement Data a dialog box appears with a list of available Span data files Select the data file you wish to recall click the Open button and the requested data file will be opened In Windows the Span data files are given the extension spd Save Measurement Data Selecting Save Measurement Data will save the current set of Span measurements t
8. Chesapeake Sailing Yacht Symposium Annapolis 1991 Hazen G S A model of sail aerodynamics for diverse rig types New England Sailing Yacht Symposium 1980 Kerwin J E velocity Prediction Program for Ocean Racing Yachts SNAME New England Sailing Yacht Symposium Connecticut U S A 1976 Kerwin J E velocity Prediction Program for Ocean Racing Yachts revised to June 1978 Massachusetts Institute of Technology report no 78 11 1978 Keuning J A Sonnenberg U B Developments in the Velocity Prediction Based on the DELFT Systematic Yacht Hull Series RINA Modern Yacht Conference Portsmouth 1998 Pedric D A IMS an Almost Ideal Measurement System Yacht Vision 794 Auckland New Zealand 1994 Philpot A B Developments in VPP Capabilities Yacht Vision 94 Auckland New Zealand 1994 Poor C L VPP Algorithm description Appendix to Description of IMS VPP and LPP Algorithms IMS 1986 Page 31 Index Index 2 2nd Moment Lengths sss 27 A About Spar eene iere o tentoria 24 14 AUS iii aiii T T 12 14 26 tro ern 27 Appendages seen 14 Arrange 0422242 0000 24 B B 14 27 BAS MTM 29 Beta AW a eite seems 29 Beta TW seen 29 Body Plan ann 24 A t ie e ann 27 Cascade ae 24 Close DeSI gi iia 20 COlGUE uae ee
9. SPAN data file spd when a Maxsurf design is already open Page 11 Chapter 2 Using Span Page 12 Measuring a Maxsurf Design If you wish to measure a Maxsurf design select Open Design from the File menu and select a design You will be presented with a dialog to read or calculate the hull sections Ifthe design has been used in Hydromax the sections may have already been calculated and may be read from the file if not they must be calculated refer to the Hydromax Manual section Opening a New Design for further details Section Calculation Options ons from Surface Precision Medium C Highest Calculate sections Include Plating Thickness Use Trimmed Surfaces Stations C Use Maxsurf Station Positions 200 max 50 Evenly Spaced 100 Evenly Spaced 200 Evenly Spaced Once the design has been read in and the sections calculated Span will measure the hull to find the data required for the VPP You will be asked whether you wish Span to search for the values of AGS and SBMAX See Hull parameters on page 26 in the Nomenclature for meanings or you specify these values at this point This may be useful if the design is an IOR type however this is not essential Span also requires the position of the VCG this is important as it affects the calculation of righting moments for the design and therefore the hull s stiffness Note that AGS and SBMAX are measured aft of the bow and VCG is measured
10. Span Windows Version 11 1 User Manual Formation Design Systems Pty Ltd 1984 2005 License amp Copyright Span Program 1987 2005 Formation Design Systems Span is copyrighted and all rights are reserved The license for use is granted to the purchaser by Formation Design Systems as a single user license and does not permit the program to be used on more than one machine at one time Copying of the program to other media is permitted for back up purposes as long as all copies remain in the possession of the purchaser Span User Manual 2005 Formation Design Systems All rights reserved No part of this publication may be reproduced transmitted transcribed stored in a retrieval system or translated into any language in any form or by any means without the written permission of Formation Design Systems Formation Design Systems reserves the right to revise this publication from time to time and to make changes to the contents without obligation to notify any person or organisation of such changes DISCLAIMER OF WARRANTY Neither Formation Design Systems nor the author of this program and documentation are liable or responsible to the purchaser or user for loss or damage caused or alleged to be caused directly or indirectly by the software and its attendant documentation including but not limited to interruption on service loss of business or anticipatory profits No Formation Design Systems distributor agent o
11. a Definitions es 29 A d H 31 32 About this Manual About this Manual This manual describes Span an application which may be used to predict the sailing performance of yachts designed using Maxsurf The manual is organised into three chapters Chapter 1 Introduction Contains a description of Span its use and its interaction with Maxsurf designs Chapter 2 Using Span Explains how to use Span s performance prediction VPP to best advantage Chapter 3 Span Reference Gives details of each of Span s windows toolbars and menu commands Chapter 4 Theoretical Reference Contains a list ofkey words and abbreviations used in this manual and provides a literature list for the interested reader Page 1 Chapter 1 Introduction Chapter 1 Introduction SPAN Sailing Performance Analysis is a program for predicting the performance of sailing yachts in a variety of wind conditions Based on the published algorithms for the IMS Velocity Performance Prediction Program SPAN solves the equations for lift and drag for hull and rig and finds an equilibrium velocity and angle of heel Integrated into SPAN is a hull form measuring module that performs the function of the IMS Lines Processing Program LPP This allows the designer to read in a Maxsurf design and automatically perform the measurements required for input into the performance analysis Alternatively measurements may be input dire
12. below the DWL positive down Measure Hull AGS aft of bow Where the transom is created using a trimming surface the AGS should be specified by the user Search for value C Set value fi 15m SBMAX aft of bow Search for value Set value 41 VCG below DwL 0 Cancel SPAN will now measure your design floating it to several different heel and trim conditions Once the measurement is complete you will need to enter values for the rig via the Rig Data dialog unless they have been loaded from a previous Span Measurement file loading a Span Measurement file will overwrite all data measuring a Maxsurf design will only overwrite the hull data The hull data may be re measured at any time by selecting Measure Hull from the Data menu Chapter 2 Using Span Note On Hull Input Parameters Almost all the hull input parameters used by SPAN are derived from a number of hydrostatic calculations with the hull in several conditions and various weighted integral quantities These parameters are not simple linear measurements which can be taken directly from a lines plan These data can be obtained by using SPAN to measure a Maxsurf design file which includes hull and appendages or from the IMS LPP program or IMS measurement certificate Note Hull measurements which must be entered manually There are several hull parameters that SPAN is unable to measure from the hull model and which must be entered man
13. ctly from an IMS certificate although only a small number of key values are required Once a hull and rig have been fully specified the designer may calculate an entire table of performance values from 6 knots through to 20 knots true wind speed A variety of true wind angles are used and performance is calculated with both spinnaker up and spinnaker down The output from SPAN is in the form of a table of values for each wind strength and wind direction with results given for apparent wind direction and apparent wind strength hull velocity VMG heel angle and the various lift and drag forces involved Velocity data can also be viewed in the form of performance polar curves In general the results from SPAN are very close to those produced by the current IMS VPP The speeds predicted by SPAN tend to be more conservative than those predicted by IMS usually by approximately 0 1 knot however the shape of the polar curves produced by both programs tend to be very similar SPAN provides a valuable tool to the yacht designer both for the estimation of performance during the design process as well as the ability to produce polar curves of performance for the yacht owner once the design is launched Page 3 Chapter 2 Using Span Chapter 2 Using Span You have been introduced to the way in which Span works and can now go on to learn in detail how to use Span by following the example outlined in this chapter The example uses measurements
14. derived from B below An integrated value of hull width using a second moment approach and a depth attenuation factor Wetted surface area of the hull and appendages Displacement in sailing trim Effective hull lengths of the yacht under different conditions of displacement and heel These values are derived from the sectional area curve L is the effective sailing length used to calculate the hull resistance Maximum crew weight Page 27 Chapter 4 Theoretical Reference Rig Measurement Definitions All rig positions are relative to the base of the headstay The longitudinal position of the headstay base is fixed at the FGS position See Hull parameters on page 26 Figure 1 Rig data parameters Back to Entering Data Foretriangle Definitions I Height from the sheerline to the top of the foretriangle J Distance from the headstay base to the front of the mast LP Jib clew to the luff taken perpendicular to the luff SPL Spinnaker pole length SL Spinnaker luff length SMW Spinnaker maximum width Also see Figure 1 Rig data parameters on page 28 Page 28 Mainsail Definitions P E PC EC MGU MGM BAS Also see Chapter 4 Theoretical Reference Mainsail luff length from lower to upper band on the mast Mainsail foot length from the mast to the boom band The IOR corrected vales of P and C The upper and middle girth
15. dimensions of the mainsail Height of the lower mainsail luff band above the sheerline Figure 1 Rig data parameters on page 28 Mast Definitions 1 MDL 1 MDT 2 MDL 2 1 Also see Athwartships measurement and fore and aft dimension of the mast near the deck Below any taper The same measurements as above taken at the upper mainsail band If there is no mast taper the upper and lower dimensions will match and the TL will be zero Freeboard at the base of the mast Taper length of the mast Figure 1 Rig data parameters on page 28 Mizzen Definitions EB YSD YSF YSMG PYC EYC Distance between the aft side of the forward mast and the forward side of the aft mast Aft luff of mizzen foresail Bottom luff of mizzen foresail YSMG is mizzen foresail mid girth measured horizontally Mizzen mainsail luff length from lower to upper band on the mast Mizzen mainsail foot length from the mast to the boom band All mizzenmast definitions ending in Y are identical to the main mast definitions Also see Figure 1 Rig data parameters on page 28 Results Data Definitions VTW Beta B TW Spinnaker VAW Beta AW True wind speed Course relative to true wind Whether the spinnaker is set up or not down Apparent wind strength Apparent wind direction Page 29 Chapter 4 Theoretical Reference Page 30 Hull Speed VMG Heel Angle Fwd Force Sideforce Reef
16. from a simple yacht hull form SPAN sample spd The corresponding Maxsurf design file is also supplied SPAN sample Yacht msd These files may be found in the Sample Designs folder The following example goes through the steps needed to generate a polar performance curve Page 5 Chapter 2 Using Span Getting Started Installing SPAN Install Span from the CD Span may then be started and will display seven windows containing Polar performance graph Results table Upright resistance graph and four views of the current design ifany These are Perspective Plan Profile and Body Plan Opening a Measurement File Choose Open Measurement Data from the File menu Select the file titled SPAN sample and open it This file contains the hull and rig measurement data for a simple yacht hull form When it is read in the data may be modified if necessary Page 6 Chapter 2 Using Span Entering Data The data to be entered is the measurement data of an IMS certificate The following data is required e Hull Data e Rig Data e Mizzen Data e Wind Data The data is entered by selecting the appropriate dialog from the Data menu If you are entering data from an existing IMS certificate you will notice that not all the measurements listed on the IMS certificate are required SPAN only needs the essential data Hull Data In the following sections we will show you how to enter the hull da
17. in detail by enlarging any particular area to fill the screen Shrink Choosing Shrink will reduce the size of the displayed image in the front window by a factor of two Pan Choosing Pan allows you to move the image around within the front window Home View Choosing Home View will set the image back to its Home View size Span starts up with default Home View settings for the view window However the Home View may be set at any time by choosing the Set Home View function Set Home View Choosing Set Home View allows you to set the Home View in the View window To set the Home View use Zoom Shrink and Pan to arrange the view as you require then select Set Home View from the View menu Colour The Colour function allows you to set the colour of lines and controls displayed in the view windows The colours used in the graphs may also be changed Changes to the default colours will be saved in the program s preferences Span will display a list of items that allows you to set any of the items to any colour and intensity by using a colour pallet Page 21 Chapter 3 Span Reference Page 22 To set the colour of a given line or set of lines e Select Colour from the View menu e Select the line type from the scrollable list e Select a colour from the colour picker Font Font allows you to set the size and style of text used in the windows Toolbars Allows you to select which toolbars are visible see Toolbar secti
18. ment Definitions on page 28 for explanation of terms Figure 1 Rig data parameters on page 28 Wind Data Wind Data Wind Angle Upwind sailset True Wind Velocity 1 7177777777 AAA AA KAKI KIKI The Wind Data dialog is used to define the wind conditions for which you wish to calculate the performance data The default values of the dialog are set to those of the IMS VPP Page 8 Chapter 2 Using Span A maximum of 7 wind velocities may be defined Two sets of true wind angles may be defined The first is the wind angles for which the upwind sail set will be used and the second the wind angles for which the downwind sail set will be used Wind angles must have a minium spacing of 3 degrees Upwind sailing angles may be defined from 35 degrees to 110 degrees and downwind sailing angles may be defined in the range of 80 degrees to 180 degrees Rig sketch If a Maxsurf model has been loaded then a sketch of the rig will also be displayed once the rig parameters have been entered SPAN produces a graphical representation of the rig data as specified in the Rig and Mizzen dialogs This provides useful visual feedback of the rig parameters specified A You can display the rig sketch using the button on the display toolbar Profile view The colour of the rig sketch can be set in the colour dialog from the view menu by editing the label colour
19. n e Windows Toolbars e Menus Page 17 Chapter 3 Span Reference Page 18 Windows Span uses a range of windows Results Performance Data Window The Results Performance Data window display s a table with the results of the analysis including apparent wind speed and direction hull speed VMG heel angle etc Polar Graph Window The Polar Graph window display s a polar performance graph of yacht speed versus wind direction for the different speeds tested Upright Resistance Window The Upright Resistance window display s a graph of the upright hull resistance against hull speed Chapter 3 Span Reference Toolbars Users ofthe Windows version of Span can use the icons on the toolbars to speed up access to some commonly used functions You can hold your mouse over an icon to reveal a pop up tip of what the icon does File Toolbar 0594 28 89 The File toolbar contains icons which execute the following commands New Data Open Design Save Data Cut Copy Paste Print Preview View Toolbar The View toolbar contains icons which the following commands Zoom Shrink Pan Home View Contour Toolbar 5 The Contours toolbar contains icons which facilitate the display of surface contours Sections Waterlines Buttocks Intersections Edges Window Toolbar ESSE Pie The Window toolbar contains icons which make
20. ndow Menu 23 Window Toolbar 19 Windows ae 18 Wer ER chore EM dz 27 Y YD REDE EE EE 29 era ese eta 29 34
21. nu item to open a dialog which will allow you to enter or edit the data which defines the hull The nomenclature used is that of the IMS Rig Data Use this menu item to open a dialog which will allow you to enter or edit the data which defines the main rig mainsail and jib The nomenclature used is that of the IMS Mizzen Data Use this menu item to open a dialog which will allow you to enter or edit the data which defines the mizzen sail The nomenclature used is that of the IMS Wind Data Use this menu item to open a dialog which will allow you to enter or edit the data which defines the wind conditions for which you wish to calculate the performance data The default values are set to those of the IMS VPP A maximum of 7 wind velocities may be defined Two sets of true wind angles may be defined The first is the wind angles for which the upwind sail set will be used and the second the wind angles for which the downwind sail set will be used Wind angles must have a minium spacing of 3 degrees Upwind sailing angles may be defined from 35 degrees to 110 degrees and downwind sailing angles may be defined in the range of 80 degrees to 180 degrees Units A variety of metric and imperial units may be used in Span This command gives you a dialog box where you may choose your preferred units Irrespective of the default units specified the Markers window will accept dimensional data in any units For Example if the default uni
22. o disk Save Measurement Data As Selecting Save Measurement Data As enables you to save the current set of Span measurement under anew name This is useful if you modify the data but wish to keep a copy ofthe old version as well as the new Page Setup The Page Setup dialog allows you to change page size and orientation for printing Print Choosing the Print function prints out the contents ofthe uppermost Span window Recent File Opens the last file open in Span Exit Exit will close down Span and return you to the Desktop If Span has a set of markers or a surface open that has not been saved to disk you will be asked whether you wish them to be saved Chapter 3 Span Reference Edit Menu The Edit menu contains commands for working in the Results window In addition graphs or design views may be copied to the clipboard Undo Undo may not be used is Span at this point Cut Cut may not be used in Span at this point Copy Copy may be used to copy data from the Results table It may also be used to copy the contents of one ofthe view windows or graph windows into a picture or metafile which may then be pasted into other programs Paste Paste may not be used in Span at this point View Menu The View menu contains commands for changing the way in which the drawing and data windows are displayed Zoom The Zoom function allows you to examine the contents ofthe Perspective Plan Body Plan or Profile window
23. om the File menu Similarly data from any window can be copied into the clipboard and pasted into other applications Page 15 Chapter 2 Using Span Page 16 Results Table The Results table contains the numerical values of the data plotted in the Polar Graph Additional data are also included See Results Data Definitions in the Nomenclature on page 29 for an explanation ofthe terms and abbreviations used in the results table Polar Graph The results may also be presented in a polar graph form This plots the speed of the yacht against the course for different true wind strengths and sail combinations spinnaker up or down The yacht velocity is represented by a vector from the centre of the graph Polar Plots of all results data are possible use the Display Plot Options dialog to select the data to be plotted Note that the graphs are only smoothed where it is sensible to do SO A Polar Graph CE 0 x i 5 2 97 5 T Crew Right Moment Force Err beta TW deg Downwind 20 kts 8 605 kts beta TW 0 000 deg Vmg 8 605 Upright Resistance Graph The curve of upright resistance of the hull as predicted by Span can be viewed in the Upright Resistance window This does not include the induced resistance due to the appendages generating sideforce Chapter 3 Span Reference Chapter 3 Span Reference This chapter describes the windows toolbars and menu commands available in Spa
24. on for more details Status Bar The Status Bar command makes the Status Bar at the bottom of the screen visible This Status Bar displays information about the current state of what is being viewed in the window short descriptions of the functions of some commands as your mouse passes over them and indicates the state of some control keys Solve Menu The solve menu is used to solve the VPP for the predefined range of true wind speeds and heading angles Solve Multiple Angles Selecting Solve Multiple Angles sets Span to work solving the VPP for the predefined true wind speeds and course angles These are as follows True wind speed 6 8 10 12 14 16 20 kts True course upwind spinnaker 35 39 42 45 50 60 75 90 100 110 down True course downwind spinnaker 80 90 100 110 120 130 140 150 165 175 up 180 Display Menu The Display menu contains commands for turning on and off items displayed in the graphics windows Plot Options The Plot Options dialog allows you to select which data are plotted on the polar graph Contours The Contours option allows you to select which contours are drawn on the screen at any given time Any combination of contours may be chosen from the contours dialog See Maxsurf manual for further details Data Menu Data menu contains command s for setting the hull and rig parameters used in the VPP Chapter 3 Span Reference Hull Data Use this me
25. pendages If no keel is included the hull data will not produce reasonable values It is also essential that the appendages fulfil the analysis requirements of Hydromax in that they should form topologically closed surfaces i e they should not have open tips or open trailing edges Trimmed surfaces in Maxsurf The untrimmed hull surface is used to find AGS FF FA SBMAX and B so it may be necessary to specify these yourself if you are using a trimming transom and or deck surface See also note on appendages above Accuracy The VPP results can be quite sensitive to hull measurements so you should use 200 measurement stations under most circumstances This is especially true if you have a keel bulb Chapter 2 Using Span Calculating Performance Data Once all values have been entered you are ready to proceed with the calculation of performance data Select Solve Multiple Angles from the Solve menu Span will calculate the performance values for the yacht and display the results in the Results table and graphs Span will calculate performance for a range of courses at wind strengths of 6 8 10 12 14 16 amp 20 knots with the spinnaker up and down XS Polar Graph EEE Results Hull Speed kts 27 120 4 5 6 beta TW deg Speed kts Downwind 20 kts 8 605 kts beta TW Vir Hull Drag 0 001 kN Speed 0 000 kts The data shown in any window can be printed using the Page setup and Print commands fr
26. r employee is authorised to make any modification extension or addition to this warranty Contents License amp Copycat Raten 111 COS RS M A EE ANENE About bri 1 Chapter 1 Introduction ett e ea gait Ee ERR ege Seda 3 Chapter 2 Using Span ote ote tea ee rete ood see ana 5 Getting Started ER 6 Entering E cose bons Ceveabaventete s 7 Measurement File EE 11 Saving a Measurement File 11 Opening a Measurement File nennen 11 Measuring a Maxsurf Design 12 Calculating Performance Data sess 15 Results Tal ILES 16 3 5 ss 17 WINDOWS Em 18 M 19 20 File Men ES 20 Edit i T 21 VIEW MENU int 21 STIMMT 22 Display Men ai nl Rn 22 Data Menu 22 Window O ENEAN 23 Help iii 24 Chapter 4 Theoretical Reference 25 Nomenclature secorre sense aa 26 Hull Measurement Definitions 26 Measurement Definitions 28 Results Dat
27. ta manually However in most cases it is much simpler to have the data measured from Maxsurf design this is described in the Measuring a Maxsurf Design section below Hull Data m Freeboards gt r Sailing trim FF 128m AMS1 f 33 m 2 D 1 996 FA 1 039m BTR 402 B Righting moment deg DHKA 2353 m WS 83 07 m 2 RM2 0 2tonne m deg ECMA 0 DISP 86 t RM20 0 2 tonne m deg na RM40 D 2tonnem deg L 3 976 m LSM3 9 851 m Measurement trim LsM1 8958 m MBMX 4 035 m Crew weight ck PIPA 0 007 m 2 Cw 107 be ancel See Hull Measurement Definitions on page 26 for explanation of terms Rig Data Rig Data r Foresails r Mast 7 r Mainsail 16 605 m MDT1 0 116 m 14 783 m J 4843 m 0 213 m E 4 203 m LP 7 802 m MDT2 0 116 m MGU 1 554 m SPL 4871 m MDL2 0152 m MGM 2743 m SL 16 002 m HEI 1 126 m BAS 2102 m SMW 8 778m TL 262 Full length battens Cancel Page 7 Chapter 2 Using Span Also see Rig Measurement Definitions on page 28 for explanation of terms Figure 1 Rig data parameters on page 28 Mizzen Data Mizzen Data ES EB MDTIY Om HBIY 12m YSD Em MDL1Y o m Pr p 512m 46m Om wre 22m YSMG 32m Om Basy 1 3m nv om Cancel Y character denotes a mizzen measurement Also see Rig Measure
28. ts were metres all of the following input would be accepted and converted accordingly 3 interprets as 3 00 metres 2 5c 3 25 33cm 4 inches 328mm 5 4 650 44mil 11 25feet 6ft 3 1in 5f5I Measure Hull Selecting Generate Measure Hull instructs Span to calculate the necessary measurements form the Maxsurf design file A dialog is presented and the user may specify AGS and SBMAX or ask Span to search for these values In addition the VCG must also be specified Window Menu Selecting item in the Window menu brings the appropriate window to the front on the screen Page 23 Chapter 3 Span Reference Page 24 Cascade This function stacks up all the currently visible windows into the bounds of the screen in a staggered arrangement Tile Horizontal Tiles the open windows horizontally within the application window Tile Vertical Tiles the open windows vertically within the application window Arrange Icons Arranges the closed windows within the application window Perspective A perspective view of the hull Plan A plan view of the hull Profile A profile view of the hull Body Plan A body plan view of the hull Results Performance Data Display s a table with the results of the analysis including apparent wind speed and direction hull speed VMG heel angle etc Polar Graph Display s a polar performance graph of yacht speed versus wind direction for the different speeds tested Upright
29. ually these are not reset when the hull is measured PIPA Propeller installation projected area ECMA The vertical difference between board up and board down draft Also see Hull parameters on page 26 Checking the SPAN model Check that the sections have been formed correctly by viewing the design in the Perspective view with the sections turned on The immersed sections as well as the girth stations are displayed Important notes on SPAN Hull measuring Since SPAN can automatically calculate the IMS measurement data directly from the Maxsurf surface model it is important to understand the following Page 13 Chapter 2 Using Span Page 14 SPAN s automatic identification of the hull surface SPAN assumes that the longest surface in the design is the hull surface and uses this surface to determine the fore and aft girth stations FGS AGS the freeboards at these stations FF FA the station of maximum beam SBMAX and the beam at this station B Ifthe longest surface in your design is not the main hull you will need to save a copy of your design for use with SPAN and remove any longer surfaces from the design before reading it into SPAN you must also ensure that the main hull is made up of only one surface Alternatively you can specify the AGS SBMAX positions and FF FA and B yourself See also note on trimmed surfaces below Appendages It is essential that the Maxsurf design being measured has ap
30. vid Pedrick presented at Yacht Vision 94 Auckland New Zealand 16 20 Feb 1994 Back to Entering Data Hull parameters AGS Aft girth station DWL Design waterline FGS Forward girth station SBMAX Longitudinal position of maximum hull beam VCG Vertical centre of gravity Freeboards FFM Freeboard Vertical distance from the water to the sheerline at the forward freeboard measurement station FAM Freeboard at the aft freeboard measurement station Page 26 Chapter 4 Theoretical Reference Righting Moments per Degree Righting Moments per degree RM2 RM20 RM40 Measurement Trim MBMX PIPA Sailing Trim AMSI BTR DHKA ECMA WS DISP 2nd Moment Lengths L LSM1 LSM3 Crew Weight Limit CW Righting moment at heel angles of 2 20 and 40 degrees divided by the heel angle in degrees Maximum beam at shearline Propeller Installation Projection Area represents the equivalent flat plate area of the prop installation used to calculate its drag at various speeds Depth attenuated maximum sectional area Used to calculate the effect of the hull on the keels ability to generate lift An adjusted beam to depth ratio A measure of the fineness of the hull which has an effect on added resistance due to heeling Loaded draft somewhat deeper than measurement draft The vertical difference between board up and board down draft The draft adjusted for hull keel interaction and end plate effects and
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