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1. alone or in combination to represent practical cases as well as possible Also comments are given on where special attention should be paid to avoid numerical problems It has not been the intention to write a general textbook on marine hydrodynamics Neither has it been an intention to replace the Theory Manual or the Users Manual where a more complete description of the theory and input data is found It is our hope that the tutorial can give some additional advice to the user regarding practical use of SIMO The zip file SIMO Tutorial zip contains the necessary files The file may be downloaded from the SIMO web pages Extract the files and double click on the file SIMO modellingTutorial html to run the tutorial 4 2 System Description File generator SysGen deprecated Together with the release of SIMO 3 4 0 the utility SysGen was made available The purpose of SysGen is to read hydrodynamic coefficients from WAMIT result files wamit out wamit 1 wamit 4 etc calculate retardation functions and write all relevant data to a SIMO system description file The following data groups are written if present on the Wamit result files Mass data including added mass matrix infinite zero Hydrostatic stiffness First order wave force transfer functions First order motion transfer functions Retardation functions Second order wave drift coefficients Hydrodynamic interaction between bodies e Coupled added mass data SIMO Releas2. 08 30 1 2 1 Decoding of input files Trailing zeros after the decimal point are now removed before decoding floating point numbers on ASCII input files 0 5 and 0 500000 will now result in the same value This may improve stability in simulations for cases where the time domain integration parameters are given with many trailing zeros Slight changes in results may occur 1 2 2 Error correction Reading wind turbine data The cone angle and twist angles were a factor of 4 too small Error in converting angles from degrees to radians 1 2 3 Improvement Static results to psc file for coupled analysis Static body results are printed to a psc type of file also when running coupled analysis This file is used by SIMA 1 2 4 Error correction Time series of global accelerations The double derivatives of Euler angles have been replaced by rotational body accelerations for time series presentations No consequence to results except for the presented acceleration signals 1 2 5 Error correction Thruster forces for visualization SIMVIS SIMA Erroneous forces stored to file to be used for visualization in SIMVIS and SIMA The error has been corrected Note No error correction with regard to thrust time series 1 e no consequence to results 1 3 SIMO 4 0 5 2013 05 16 1 3 1 Error correction Thruster force time series The thrust force time series were incorrectly stored when than one body had thrusters and both total thrust force and
3. 1 2 3 Improvement Static results to psc file for coupled analysis 4 1 24 Error correction Time series of global accelerations sss 4 123 Error correction Thruster forces for visualization SIMVIS SIMA 4 1 3 SIMO 40 5 2013 0516 etos eterna uec e Geel aid aoe atlanta end 4 1 3 1 Error correction Thruster force time series cccccescceeceeceesseceteceteeeeeeeeseees 4 132 Error correction DP yaw moment assignment sss 5 1 3 3 Improvement Diffracted wave transfer functions for wave elevation only 5 JE SIMOLA NA DOS 5D Die coer sta sacs e e a bns aad e A a M bos de 5 1 4 1 Improvement Added mass in the kinetic equation used in time domain 5 1 5 IEA 2S 522 Diao cts se ta al ai iced alts tct but CU leas ds 6 1 5 1 Improvement Dynamic positioning and thrust allocation s 6 1 5 2 Error correction Dynamic positioning esesseseseeeeeeeeeenenren nene 7 1 5 3 Error correction Diffr cted Waves eterne ie t red eni Ie PEE T 1 5 4 Improvement Diffracted WaV6s eerte acere terr eene nen deinen ek a ev atin T 1 6 SIMO 4 0 2 2013 01 11 east dace E E E S a teil 7 1 6 1 Error correction Dynamic positioning essere T 1 6 2 Error correction Dynamic positioning thrust allocation 7 1 6 3 Error correction Wind specification eid eene Le ee er et PED aded 7 1 6 4 Imp
4. 1 Controllable tensioner Hydraulic pneumatic tensioner May be applied in coupled dynamic simulation of pipe laying where the mean force can be controlled to ensure symmetric motion about mid stroke position The mean force may also be controlled over HLA in the MARINTEK simulator set up 3 8 2 Active heave compensator The intention is to facilitate the modelling of an active HC where the vertical motion of the suspended load is minimized preferably so that the HC piston moves around its mean stroke position 3 9 Crane modelling and crane operations This feature has been accomplished by defining a SIMO articulated structure The articulated structure is a collection of bodies constituting a crane The joints have to be of type slide telescoping or hinged It is possible to predefine a motion sequence or it may be controlled over HLA in the MARINTEK simulator set up 3 10 Wind Turbine The wind turbine modelling feature is implemented as an alternative wind load model The wind load computation is based on a Blade Element Momentum BEM method for dynamic analysis of horizontal axis wind turbines This feature includes a control system for collective blade pitch and power take off This model involves the possibility to import turbulent full field wind inflow 3 11 Modelling and accuracy improvements e The calculation method for bodies with large rotations has been improved Thereby the mathematical singularity in the Euler angle expres
5. individual thruster forces were stored The error did not affect other simulation results SIMO ReleaseNotes 40 7 docx MARINTEK 2 1 3 2 Error correction DP yaw moment assignment DP system assigned large yaw moments to thrusters when the heading error was 0 which was miscalculated to 360 The error has been corrected 1 3 3 Improvement Diffracted wave transfer functions for wave elevation only Diffracted transfer functions may now be given for wave elevation only Previously this was not allowed when waves were generated by FFT 1 4 SIMO 4 0 4 2013 03 22 1 4 1 Improvement Added mass in the kinetic equation used in time domain Modelling of non linear kinetic effects related to added mass was found not to be strictly correct This showed itself as a tendency to give e g too large roll motions compared with model test results The reason was found 1 to be unfavourable treatment of the frequency independent part of added mass which was assumed to be constant in body fixed frame of reference and ii that the relative fluid flow past the body used in the kinetic equation included the wave frequency part of body motions These shortcomings have been corrected by modelling the added mass as constant in the body related frame of reference and by low pass filtering the vessel velocities before using them in the kinetic equation It is not straight forward to specify an appropriate filter period therefor the user is offered the f
6. MARINTEK Norwegian Marine Technology Research Institute Postal address P O Box 4125 Valentinlyst NO 7450 Trondheim NORWAY Location Marine Technology Centre Otto Nielsens veg 10 Phone 47 7359 5500 Fax 47 7359 5776 http www marintek sintef no Enterprise No NO 937 357 370 MVA SINTEF MEMO MEMO CONCERNS SIMO 4 0 7 Release Notes COMMENTS ARE INVITED FOR YOUR INFORMATION FOR YOUR ATTENTION AS AGREED DISTRIBUTION SIMO Users FILE CODE CLASSIFICATION P Unrestricted REFERENCE NO PROJECT NO DATE PERSON RESPONSIBLE AUTHOR NUMBER OF PAGES 516412 2013 09 19 Harald Ormberg amp Knut Mo 12 This memo contains project information and preliminary results as a basis for final report s MARINTEK accepts no responsibility of this memo and no part of it may be copied MARINTEK 2 Contents I SEMCETEleasES aoro A E EO E EE 4 1T SIMO 4 0 7 2013 0919 nanan d Rer ti ee er ten ese iei entre t plus 4 1 1 1 Mooring system optimization STAMOD sse 4 1 1 2 Avoid printed error message indicating error termination sss 4 1 1 3 Error handling and Jay OU s uere oett uber aesti hore scd lA eiui vs 4 1 2 S INIO 4 0 ODOURS aids taal Ir sary qase sa ete nate Bieta save ote lee p Mids NR EIS Ren 4 1 2 1 Decoding OF input files su ei mte tended ce leet eae Re e ett 4 1 2 2 Error correction Reading wind turbine data sss 4
7. eNotes 40 7 docx MARINTEK H e Coupled retardation functions Note that the present version of SysGen does not write QTF data SysGen is run from a console window java jar path to SysGen jar wamit out Options time delay lt dt gt retardation function time delay Default 0 5 pressure drift force by pressure info info messages SysGen requires a java virtual machine to be installed on your system Virtual machines can be downloaded from http www java com Please note that SysGen is beta software The sys file produced by this utility should be thoroughly checked SIMO INPMOD is the recommended tool for sys file generation for cases where hydrodynamic interaction between vessels is not present SysGen does not read sif files from WADAM directly As a work around for WADAM users that want to use SysGen one may specify WADAM to export results to WAMIT For more information confer WADAM User Manual DNV Software 4 Define Run Run WadamA unt Db Input Execution Directives Output Directory Globalresponse Structuralloads Datacheck Pz Constants Wave Drift Forces Roll Damping Equation Solver Print Result Fies Advanced Logarithm singularity C Numerical Analytical Qo Numerical integration Onenode Gauss FournodeGauss Q Panel dimension Area Maximum diagonal Irregular frequencies Remove v Save temp amit files Stop before Poten Bypass Poten Stop before frst Force By
8. easeNotes 40 7 docx MARINTEK d 1 5 2 Error correction Dynamic positioning An error in the DP control module when dynamic positioning and mooring was used simultaneously has been identified In this case a false constant bias force was added to the force from the thrusters This defect has been corrected 1 5 3 Error correction Diffracted waves A potential error with regard to systems with a large number of diffracted wave specifications and applications has been identified This has been corrected 1 5 4 Improvement Diffracted waves Application of diffracted wave elevation alone and not only in context with diffracted wave velocity has made possible 1 6 SIMO 4 0 2 2013 01 11 1 6 1 Error correction Dynamic positioning The required rate of change of thrust direction did not work That is the limitation in change of thrust direction did not work This resulted in a momentary change in the direction of azimuth thrust direction set to required direction This gave non conservative results Fixed 1 6 2 Error correction Dynamic positioning thrust allocation When the thrust command of a thruster is greater or equal to the maximum allowed thrust of the thruster the allocation algorithm try to find a new solution by reassigning the thrust to the other thrusters If the thruster system is not redundant this can lead to absurd answers since the solution is unique anyway Fixed The compensation algorithm is jumped over
9. her thrust forces in case one thruster experience saturation e For azimuth thrusters the allocation algorithm is improved so that the new algorithm allocates the thrust with the instantaneous thruster direction 3 2 Manoeuvring Vessel manoeuvring is made possible by specification of a path for the DP reference point This option involves modelling of thrusters and a DP system SIMO ReleaseNotes 40 7 docx MARINTEK 4 3 3 Thrust force A model for the effect lifting surface of a rudder on the thrust force has been implemented 3 4 Second order wave forces due to swell Computation of second order wave forces qtf and drift forces due to swell has been implemented These forces adds to the second order wave forces due to wind waves The wave drift force from swell long periodis waves will normally be small However in some cases the specified swell 2 wave spectrum is used to add an additional wind sea from another direction 3 5 Direction dependent force coefficients The new input description allows for directions not starting from 0 For example is the direction sequence 5 35 65 335 is accepted 3 6 User specified moment It is possible to define user specified moment in addition to specified force 3 7 Ratchet coupling Ratchet type coupling characterised by its asymmetric slip lock response used in offshore installation or de commissioning of heavy structures 3 8 Body components 3 8
10. if the system is not redundant 1 6 3 Error correction Wind specification Use of wind type 11 Fluctuating uniform 2 component wind resulted uncontrolled program termination NaN This has been corrected 1 6 4 Improvement Dynamic positioning Maximum numbers of thrusters per body has been increased from 10 to 20 1 7 SIMO 4 0 1 2012 11 19 1 7 1 Error correction Distributed element force and dept dependent coefficients Several slender elements can be given under data group Distributed Element Force DEF Originally data group DEF could only be given one time for each body In visualization this was inconvenient because all slender elements were one graphic object The input to SIMO was therefore modified so that the data group DEF could be given several times for each body In SIMA each Slender Element has its own DEF group A Slender Element may have Depth dependent coefficients Internal in the program these coefficients are stored in increasing order At the system input file sys file the coefficients may be given in increasing or decreasing order An error did occur if more than 3 levels of depth dependent coefficients were given and the coefficients were given in decreasing order SIMO ReleaseNotes 40 7 docx MARINTEK 8 An error did also occur if more than 1 slender element with depth dependent coefficients were specified in the same DEF group 1 7 2 Correct reading of long real input Correc
11. names Y Read initial condition file DYNMOD main menu Set simulation parameters DYNMOD main menu Default main analysis parameters N FFT only Select method for calculation of waves 12 Integer power of 2 NFFT 0 25 Time step DT 1 Number of subdivision each step Blocked filter Select method for filtering Default method parameters N 1 5 SIMO 4 0 3 2013 03 22 1 5 1 Improvement Dynamic positioning and thrust allocation Thrust allocation means distributing the demand for total force and moment from the DP controller to the thrusters in the system Usually this can be done in many ways In Simo it is done according to an optimality criterion by which it is attempted to fulfil the demand for force and moment with as little use of thrust as possible When large total force or moment is demanded it can happen that a thruster is instructed to deliver a thrust that would exceed its capacity In this case a saturation handler routine is called which tries to distribute the excess thrust on other thrusters in the system In the previous Simo versions 4 0 there was a coding error in the saturation handler which made the allocation erratic In the new version 4 0 3 capacity exceedance in the allocation is handled by simply enforcing the limit to the thrust instead of trying to amend the situation by redistributing thrust This has proven to be a robust way to deal with the problem in most cases SIMO Rel
12. ollowing options in application of the filter 1 No filtering 2 Low pass filtering with specified cut off period 3 Complete blocking of velocities all velocity components set to zero Results will change for body type 1 for which 1 order wave forces are described in time domain i e by 1 order wave force transfer functions retardation functions and added mass at infinite frequency Note This new option requires extra input commands for dynamic analysis if waves are present Existing macro files used for dynamic analysis dynmod have to be modified e g SIMO ReleaseNotes 40 7 docx MARINTEK Example No filter Set simulation parameters DYNMOD main menu Default main analysis parameters N FFT only Select method for calculation of waves 12 Integer power of 2 NFFT 0 25 Time step DT 1 Number of subdivision each step No filter Select method for filtering Default method parameters N Example Filter Use default file names Y Read initial condition file DYNMOD main menu Set simulation parameters DYNMOD main menu n Default main analysis parameters N FFT only Select method for calculation of waves 12 Integer power of 2 NFFT 0 25 Time step DT 1 Number of subdivision each step Filter Select method for filtering 50 Filter period n Default method parameters N Example Blocked filter Use default file
13. pass first Force Stop before second Force Bypass second Force Use save restart Gr Delete c C Alestc olution File name Q 5 Run time DLL You might have to upgrade the FORTRAN dlls on your computer If you get a system error message mentioning the file DFORMD DLL run the dll install program VFRUN66AL exe found on your distribution medium SIMO ReleaseNotes 40 7 docx MARINTEK B 6 Work array size in DYNMOD and OUTMOD The size of the DY NMOD and OUTMOD work arrays may be specified using the environment variable SIMO_MEM The variables give the size in MB i e 4 times the number of million words The minimum size is 4 MB and the maximum size is 800 MB The default size of the DY NMOD and OUTMOD work arrays is 4 million words This corresponds to specifying 16MB 7 SIMO version number SIMO 4 0 is the new official version of SIMO replacing SIMO 3 6 that was initially released in December 2007 The sub version number is added to track corrections made to the version Subsequent bug fix releases will be labelled 4 0 1 4 0 2 etc The odd numbered versions e g 3 7 4 1 are reserved for internal development versions The next official release will therefore be SIMO 4 2 The version umbers 3 8 and 3 9 have not been used 8 SIMO licensing SIMO is license managed using the FLEXIm FLEXInet software license management system If you want SIMO to be usable from any networked computer on your site you mu
14. rovement Dynamic positioning ssssssseeeeeeeneeenerenenren eene T T 35 SMO ED 2012 UD aC leh a eaten MR pie oe E E held late Sea toll 7 1 7 1 Error correction Distributed element force and dept dependent coefficients 7 1 7 2 Correct reading of long real input 4 pti tapete a e UR AER dequo 8 1 8 SIMO ED O12012 T0 V7 ncn Ee EP EU NS t CERO ES de EDU qui ots USE 8 Modifications in SYSTEM FILE and MACRO files in SIMO 4 0 ce 8 3 New improved modelling functionality in SIMO 4 0 e eere eere e ertet 8 3 1 Improvements in DP modelling a i irit iteco br eb ave tegat e e tesi Edu REM 2408 8 Bod Mano EIIBh s cet sn eet e Ou tede spatio Mee ee Sa A E an DP A eI Mem LUE 8 3 9 CEBPUSETOECO Se pde uetus aede eU ens tig aads races Nac cn Ra RD LO UE 9 2 4 Second order wave forces due to swell eto Ret rote Wn tek Das etu Rye quais ea nude 9 3 5 Direction dependent force coefficients 44 eere teen annt cn nen eno nde ERR 9 3 0 User specifed MOmMENt eet eet RR Sine sev coat van nte e ono eve Y ap a ot emule S n RS 9 3 1 Ratchet eouplmp fay euo ID Et It Si as ebb tla A ean e hes eoo LR dS TUA 9 3 8 Body components iussi des iann erem ludis Ga Sirio oid deu pe a dabas eden 9 3 8 1 Controllable tensioner uet o Au pe nmt ODE eR du DR Dd Ads 9 3 8 2 Active heave compensator au ceca iere da ei aa dec debe dtl 9 3 9 Crane modelling and crane operations ener 9 S T0 Wind T urbIea eie tud
15. s a MSS B Ga HEAR a EE ARTA EEE FEAR IRI QURE OU OA UR batouna teens 9 3 11 Modelling and accuracy improvements ssssssssssseseeeeeeeeeneeeneenn enne 9 3 12 Ge eral Line Datus esset eei ce ep a dite M tatoo pee ees 10 SIMO ReleaseNotes 40 7 docx MARINTEK 3 A Useful tools erai ccsccssascssdecsbaccdensedetaddesssedutbadscaceceapaaabecesuadsausedaseedsdadccbuesdensedscuc esays 10 4 1 SIMO modelling tutorials siue ena ss seti item ac leaps sees eae beum reet e emanat 10 4 2 System Description File generator SysGen deprecated sss 10 Run umnie DLE uiii iiti pe olei ot i Edi ei aedes nae Dec NN EE 11 6 Work array size in DYNMOD and OUTMOD ceeeeee eres ee eren seen setas eto sa soto nao 12 EM hilexiociiguliiirg et roc c 12 Bo OSIMO COSI 8 WES 12 SIMO ReleaseNotes 40 7 docx MARINTEK 4 1 SIMO releases 1 1 SIMO 4 0 7 2013 09 19 1 1 1 Mooring system optimization STAMOD This functionality has been temporarily deactivated and will not be available until it has been thoroughly reviewed and tested 1 1 2 Avoid printed error message indicating error termination The message ERROR in TERMINATE WIND value for LPU not set was given during the run of STAMOD and DYNMOD This was a faulty indication of error The error message is now avoided No consequence to results 1 1 3 Error handling and layout Minor improvements in error handling and layout 1 2 SIMO 4 0 6 2013
16. sions has been eliminated Relevant SIMO ReleaseNotes 40 7 docx MARINTEK 10 examples are free fall installation method skid launched lifeboats and up ending of SPAR buoys and wind turbine towers e The numerical accuracy has been increased This has been done by applying double precision instead of single precision representation float values when solving the equations of motion This is an important improvement typically in simulation of marine operations where the focus is on forces in stiff coupling or contact elements Independent of the selected time step in the simulation numerical inaccuracies lead to non repeatable chaotic behaviour affecting the calculated forces and resulting body motion e The reference system for added mass at infinite frequency has been changed to be in accordance with the reference system for the retardation function forces resulting in more consistent behaviour 3 12 General Line Data The numerical formulation and stability of the catenary formulation of the general line modelling option have been improved 4 Useful tools 4 1 SIMO modelling tutorial Simo modelling tutorial may be a useful tool a new tool The intention of the tutorial is to give some advice on how SIMO can be used to model the marine units and the various mechanical systems often encountered in different marine operations Thus the focus has been based on experience to comment on how the numerous models available in SIMO can be used
17. st run a license manager on a server in your network Alternatively SIMO may be run on a single computer using a standalone license file In order to issue license keys for this license manager MARINTEK needs the following info on your server e License type server or standalone e Operating system and version Windows 7 Windows XP HP UX and Linux currently supported e MAC address FLEXIm hosted of the computer Please see the section Getting the FLEXIm HOSTID of a PC in the SIMO FAQ Your IT staff is probably already familiar with this procedure as FLEXIm is used by a large number of other applications e g Matlab SIMO ReleaseNotes 40 7 docx
18. tly handle reading of real input with long parts before the decimal point e g 11529732831 1 Previously such numbers were incorrectly read and gave erroneous results Longstanding limitation in SIMO 1 8 SIMO 4 0 0 2012 10 17 Initial release of SIMO 4 0 0 All corrections of errors to the SIMO 3 6 versions have been implemented in the SIMO 4 0 0 version 2 Modifications in SYSTEM FILE and MACRO files in SIMO 4 0 In version there is some new modelling possibilities Description of new functionality is not described There has been one change in the DYNMOD macro file In version 3 6 there was a misleading question Store SUM SPECIFIED FORCES N In version 4 0 this question has been changed to Store SPECIFIED FORCE for any body N In version 3 6 the SPECIFIED FORCE input at the sys file had to be a force In version 4 0 the specified force can also be a moment Version3 6 IMETH 2 or 3 gt Parameter IDOF IMOM is dummy Version 4 0 IMETH 2 or 3 gt Parameter IDOF IMOM is a force moment switch IMOM IMOM 0 gt Force is specified IMOM 1 gt Moment is specified 3 New improved modelling functionality in SIMO 4 0 3 1 Improvements in DP modelling These improvements include e The possibility to specify a 3x3 stiffness matrix to account for restoring forces e The possibility to specify a force table to account for nonlinear forces from a single hawser or a single mooring line e No reduction of ot
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