# Natural frequency DeepCWind and Random Seeds **URL:** \ **Category:** Computer-Aided Engineering Software Tools\ **Created:** [March 11, 2021, 8:46am UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421 "2021-03-11T08:46:09Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Andre.White](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/andre.white/32/3094_2.png) [@Andre.White](https://forums.nlr.gov/u/Andre.White)\ **Post date:** [March 6, 2023, 9:27am UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/41 "2023-03-06T09:27:27Z")
Hi @Jason.Jonkman, I am getting an error in TurbSim when I try to create a wind field for the DeepCwind platform. I posted a message under structural engineering. I was wondering if you could help me to sort it out. Thank you. Regards, AOAW ---
**Author:** ![Jason.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/jason.jonkman/32/3086_2.png) [@Jason.Jonkman](https://forums.nlr.gov/u/Jason.Jonkman)\ **Post date:** [March 6, 2023, 4:30pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/42 "2023-03-06T16:30:44Z")
Dear @Andre.White, Presumably you are referring to the following forum post: [Query about TurbSim error](https://forums.nlr.gov/t/query-about-turbsim-error/4583). I’m not familiar with the issue and have forwarded the question on to someone else to respond. Best regards, ---
**Author:** ![Andre.White](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/andre.white/32/3094_2.png) [@Andre.White](https://forums.nlr.gov/u/Andre.White)\ **Post date:** [March 6, 2023, 8:28pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/43 "2023-03-06T20:28:11Z")
Hi @Jason.Jonkman, Thank you. One more thing, do you know where I can find openfast files for v2.6.0 or v3.0.0. I know where to find binaries but not the related files. I can only access v3.4.1 on Github. Regards, AOAW ---
**Author:** ![Jason.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/jason.jonkman/32/3086_2.png) [@Jason.Jonkman](https://forums.nlr.gov/u/Jason.Jonkman)\ **Post date:** [March 6, 2023, 9:23pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/44 "2023-03-06T21:23:23Z")
Dear @Andre.White, The “assets” section of the releases page contains the files: - For the OpenFAST code: [Releases · OpenFAST/openfast · GitHub](https://github.com/OpenFAST/openfast/releases) - For the OpenFAST input files (examples/test cases): [Releases · OpenFAST/r-test · GitHub](https://github.com/OpenFAST/r-test/releases) Of course, if you are using the functionality of GitHub, you can access the full history of changes to the code and input files over time. The releases are simply tagged commits of the files stored within the GitHub repository. Best regards, ---
**Author:** ![Andre.White](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/andre.white/32/3094_2.png) [@Andre.White](https://forums.nlr.gov/u/Andre.White)\ **Post date:** [March 7, 2023, 10:59am UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/45 "2023-03-07T10:59:32Z")
@Jason.Jonkman thank you. Regards, AOAW ---
**Author:** ![Andre.White](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/andre.white/32/3094_2.png) [@Andre.White](https://forums.nlr.gov/u/Andre.White)\ **Post date:** [March 7, 2023, 1:20pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/46 "2023-03-07T13:20:52Z")
Hi @Jason.Jonkman: I am trying to run openfast v2.5.0 but the program does not execute. I only get this: _C:\Users\COAST\openfast2.5.0\r-test\gluecodes\openfast\v2.5.0\_openfast\_5mw\5MW\_OC4Semi\_Linear\>C:\Users\COAST\openfast2.5.0\openfast\_v2.5.0\_binaries\openfast\_x64.exe 5MW\_OC4Semi\_Linear.fst_ _PS C:\Users\COAST\openfast2.5.0\r-test\gluecodes\openfast\v2.5.0\_openfast\_5mw\5MW\_OC4Semi\_Linear\> openfast 5MW\_OC4Semi\_Linear.fst_ I have the executables in the bin folder and everything seems to be set-up correctly but it does not run. Do you have any idea why this could be so? Regards, AOAW ---
**Author:** ![Andre.White](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/andre.white/32/3094_2.png) [@Andre.White](https://forums.nlr.gov/u/Andre.White)\ **Post date:** [March 7, 2023, 1:28pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/47 "2023-03-07T13:28:57Z")
Hi @Jason.Jonkman: I substituted executable in v2.5.0 for another and the program runs but ofc there is the MHK error due to incompatibility issues. So not sure what is wrong with executable for v2.5.0 Regards, AOAW ---
**Author:** ![Jason.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/jason.jonkman/32/3086_2.png) [@Jason.Jonkman](https://forums.nlr.gov/u/Jason.Jonkman)\ **Post date:** [March 7, 2023, 1:50pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/48 "2023-03-07T13:50:29Z")
Dear @Andre.White, I’m not following. What output or error do you get when try to execute OpenFAST v2.5? Regarding the MHK error, are you saying this is because you are using OpenFAST input files that are not compatible with OpenFAST v2.5? Best regards, ---
**Author:** ![Dimitra.Karystinou](https://avatars.discourse-cdn.com/v4/letter/d/ecc23a/32.png) [@Dimitra.Karystinou](https://forums.nlr.gov/u/Dimitra.Karystinou)\ **Post date:** [March 7, 2023, 1:50pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/49 "2023-03-07T13:50:47Z")
Dear @Jason.Jonkman I have a similar question regarding the differences between several versions of openFAST. I am running simulations with the OC4 semisubmersible floating structure and I am using version 3.0.0. I tried to compare the free decay test cases (Load Cases 1.3a,1.3b ,1.3c and 1.3d) with the ones obtained by NREL OC4 project which have been simulated with FAST v7.01. When comparing them, I noticed that, although the natural frequencies quite similar, the damping ratio is different. I also tried with an older version of openFAST (v.2.4.0) but there were still some differences between all three (NREL, 2.4.0 and 3.0.0). I have also seen other references for variations between the different versions but I couldn’t figure out where was the mistake. So I was wondering if those are mostly related to the changes of the HydroDyn module between the different versions or if I am missing something in the simulation setup. I have also to note here that I tried with different degrees of freedom being activated, for example having only the corresponding degree of the free decay test ( only PtfmSurge for surge free-decay) and also with all the 6DOFs active but the variations still exist in some DOFs. ![Surge_FreeDecay](https://europe1.discourse-cdn.com/nrel/original/2X/e/e6beb0ecea1bbffaa414b43fd16df2eab8dc73b7.png) Thank you in advance. Regards, Dimitra ---
**Author:** ![Jason.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/jason.jonkman/32/3086_2.png) [@Jason.Jonkman](https://forums.nlr.gov/u/Jason.Jonkman)\ **Post date:** [March 7, 2023, 3:23pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/50 "2023-03-07T15:23:13Z")
Dear @Dimitra.Karystinou, Actually, the original NREL results for OC4 Phase II were submitted with FAST v8 (not FAST v7). There are likely some differences in results between different OpenFAST versions (to fix bugs and add new features), e.g., based on the discussion in the OpenFAST issue on GitHub that I linked to in my post dated Mar 2, 2023 above. There could also be differences as a result of differing implementations of the damping (potential flow, strip theory, added linear damping matrix, and added quadratic drag matrix). Best regards, ---
**Author:** ![Andre.White](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/andre.white/32/3094_2.png) [@Andre.White](https://forums.nlr.gov/u/Andre.White)\ **Post date:** [March 7, 2023, 5:00pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/51 "2023-03-07T17:00:16Z")
Hi @Jason.Jonkman: It is not really an “error”. The program does not run and I only see the following lines on the screen: _C:\Users\COAST\openfast2.5.0\r-test\gluecodes\openfast\v2.5.0\_openfast\_5mw\5MW\_OC4Semi\_Linear\>C:\Users\COAST\openfast2.5.0\openfast\_v2.5.0\_binaries\openfast\_x64.exe 5MW\_OC4Semi\_Linear.fst_ _PS C:\Users\COAST\openfast2.5.0\r-test\gluecodes\openfast\v2.5.0\_openfast\_5mw\5MW\_OC4Semi\_Linear\> openfast 5MW\_OC4Semi\_Linear.fst_ Hope I am clear now. Just wanted to know if you have any idea why v2.5.0 is not executing? I do what I would have normally done, so not sure. Regards, AOAW ---
**Author:** ![Andre.White](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/andre.white/32/3094_2.png) [@Andre.White](https://forums.nlr.gov/u/Andre.White)\ **Post date:** [March 7, 2023, 5:15pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/52 "2023-03-07T17:15:18Z")
Hi @Jason.Jonkman , Regarding the MHK issue, what I am saying is that because the executable for v2.5.0 does not seem to be working, I tried to use the executable for v3.4.1 instead. It did run, but there was an error, because I used v2.5.0 with v3.4.1 executable. Regards, AOAW ---
**Author:** ![Derek.Slaughter](https://avatars.discourse-cdn.com/v4/letter/d/46a35a/32.png) [@Derek.Slaughter](https://forums.nlr.gov/u/Derek.Slaughter)\ **Post date:** [March 7, 2023, 7:01pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/53 "2023-03-07T19:01:35Z")
@Andre.White, This is probably not the issue, but try running the command from the Command Prompt (cmd.exe) instead of PowerShell. I’ve had issues with PowerShell when running older software. In the meantime, I’ll see if I can reproduce the issue on my system. ---
**Author:** ![Derek.Slaughter](https://avatars.discourse-cdn.com/v4/letter/d/46a35a/32.png) [@Derek.Slaughter](https://forums.nlr.gov/u/Derek.Slaughter)\ **Post date:** [March 7, 2023, 7:22pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/54 "2023-03-07T19:22:33Z")
@Andre.White, Another possible issue could be missing DLL files. OpenFAST 2.5.0 required the Intel Fortran runtime libraries to exist on your system, though I would have expected it to give you an actual error message. The libraries can be downloaded from [Intel® C++ and Fortran Compilers Redistributable Libraries by Version](https://www.intel.com/content/www/us/en/developer/articles/tool/compilers-redistributable-libraries-by-version.html). Also, try running the executable without specifying the input file. Thanks, Derek ---
**Author:** ![Andre.White](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/andre.white/32/3094_2.png) [@Andre.White](https://forums.nlr.gov/u/Andre.White)\ **Post date:** [March 7, 2023, 11:21pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/55 "2023-03-07T23:21:55Z")
Hi @Derek.Slaughter, Thank you. I think I was missing some of the Fortran compilers as I started with a new computer and had not realized that all of them were not installed; since I was using newer version of openfast. The cmd line is what made me realize it fully though. It displayed a message to say some respective .dll files were missing. All in all, problem solved. Thanks again. Regards, AOAW ---
**Author:** ![Andre.White](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/andre.white/32/3094_2.png) [@Andre.White](https://forums.nlr.gov/u/Andre.White)\ **Post date:** [March 21, 2023, 12:43pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/56 "2023-03-21T12:43:33Z")
Hi @Jason.Jonkman: I am comparing my results with the results from the paper, Offshore Code Comparison Collaboration Continuation Within IEA Wind Task 30: Phase II Results Regarding a Floating Semisubmersible Wind System. Can I use the figures 4 and 5 (surge and heave free decay test) from the paper and indicate that I have taken from the paper? I am trying to find a way to show how my results compare with the ones from said paper. Thank you. Regards, AOAW ---
**Author:** ![Jason.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/jason.jonkman/32/3086_2.png) [@Jason.Jonkman](https://forums.nlr.gov/u/Jason.Jonkman)\ **Post date:** [March 21, 2023, 12:58pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/57 "2023-03-21T12:58:38Z")
Dear @Andre.White, Are you asking about how to reference cite the paper or how to obtain the numerical results included in the figures? For the former, you can reproduce the image with a proper citation of the source. For the latter, you can find the numerical results from Phase II of the IEA Wind Task 30 OC4 project in the Google drive I linked to on March 2, 2023 above. Best regards, ---
**Author:** ![Andre.White](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/andre.white/32/3094_2.png) [@Andre.White](https://forums.nlr.gov/u/Andre.White)\ **Post date:** [March 21, 2023, 1:07pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/58 "2023-03-21T13:07:47Z")
Thanks @Jason.Jonkman. You have answered both questions. Thanks again. Regards, AOAW ---
**Author:** ![Andre.White](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/andre.white/32/3094_2.png) [@Andre.White](https://forums.nlr.gov/u/Andre.White)\ **Post date:** [March 24, 2023, 12:40pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/59 "2023-03-24T12:40:42Z")
Hi @Jason.Jonkman: I downloaded the data from Google Drive and compared the free decay tests that I did with the results from NREL. For the surge free decay test, the results for the heave freedecay and pitch\_freedecay and even the surge freedecay do not compare well with results from NREL. For the heave free decay, the pitch and surge motions do not compare well with results from NREL but the heave motions compares well. I have shown the plots below. I see that in almost all cases the damping is different from the damping for NREL. Let me know what you think and if there is any way to improve as subsequent modelling results will seem as if they are not credible. Thank you. _Heave free decay test_ ![HeaveVsTime_heavefreedecay](https://europe1.discourse-cdn.com/nrel/original/2X/d/dfc8b899dc7bb2cc337cf918f21cc5f617b522da.png) ![pitchVsTime_heavefreedecay](https://europe1.discourse-cdn.com/nrel/original/2X/6/66608da98e206284c4f9fe78773c2e81a806429f.png) ![SurgeVsTime_heavefreedecay](https://europe1.discourse-cdn.com/nrel/original/2X/a/ac1402472d9fe1f39fd839ce8498179db83879dc.png) _Surge free decay test_ ![SurgeVsTime_surgefreedecay](https://europe1.discourse-cdn.com/nrel/original/2X/c/cd993e926c4e21a4055c4a4183445575319858f6.png) ![pitchVsTime_surgefreedecay](https://europe1.discourse-cdn.com/nrel/original/2X/c/c60b61761a7954b357242fd2699b509f60100342.png) ![HeaveVsTime_surgefreedecay](https://europe1.discourse-cdn.com/nrel/original/2X/6/62e53dc9468549e4861b1325b945da272c8e10cb.png) ---
**Author:** ![Jason.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/jason.jonkman/32/3086_2.png) [@Jason.Jonkman](https://forums.nlr.gov/u/Jason.Jonkman)\ **Post date:** [March 24, 2023, 12:59pm UTC](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421/60 "2023-03-24T12:59:55Z")
Dear @Andre.White, Are you using the latest OpenFAST model of the NREL 5-MW baseline wind turbine atop the OC4-DeepCwind semisubmersible provided by NREL, or did you change this model in some way: [r-test/glue-codes/openfast/5MW\_OC4Semi\_WSt\_WavesWN at main · OpenFAST/r-test · GitHub](https://github.com/OpenFAST/r-test/tree/main/glue-codes/openfast/5MW_OC4Semi_WSt_WavesWN)? Best regards, [Previous page](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421.md?page=2) [Next page](https://forums.nlr.gov/t/natural-frequency-deepcwind-and-random-seeds/2421.md?page=4)