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by Jason.Jonkman
Wed Aug 12, 2020 8:57 am
Forum: Testing
Topic: Error running HydroDyn file
Replies: 12
Views: 4746

Re: Error running HydroDyn file

Dear Ka.Ching, I still see a bit of ringing in the vertical load, although much better than before. If you haven't already, I would plot PtfmHeave and ensure that you have set its initial value in ElastoDyn to its expected mean value from the time series. You still have not provided me with enough i...
by Jason.Jonkman
Wed Aug 12, 2020 8:23 am
Forum: General
Topic: openfast v2.3
Replies: 6
Views: 175

Re: openfast v2.3

Dear Ioannis,

Perhaps the model requires just about 2-GB of RAM and the OpenFAST v2.3 memory requirements are slightly more than FAST v8.16? You may be able to solve the memory problem by eliminating a few analysis nodes from the model.

Best regards,
by Jason.Jonkman
Wed Aug 12, 2020 7:07 am
Forum: Systems Engineering Software Tools
Topic: Installation of OpenFAST
Replies: 15
Views: 7651

Re: Installation of OpenFAST

Dear Vishal,

I'm not a aware of a free license for the Intel Fortran compiler for commercial use, but that is a question better answered by Intel.

Best regards,
by Jason.Jonkman
Wed Aug 12, 2020 6:58 am
Forum: General
Topic: openfast v2.3
Replies: 6
Views: 175

Re: openfast v2.3

Dear Ioannis, The MATLAB Toolbox was historically updated to support upgrading FAST input files from v7 to v8 and between various releases of FAST v8. But these tools have not been updated to support the transition to various versions of OpenFAST. That said, the input file changes in OpenFAST have o...
by Jason.Jonkman
Tue Aug 11, 2020 12:02 pm
Forum: Computer-Aided Engineering Software Tools
Topic: NREL15MW
Replies: 2
Views: 23

Re: NREL15MW

Dear Gonzalo, When you disabled SubDyn, did you also disable the platform degrees of freedom in ElastoDyn (PtfmSurge = False, etc.)? If not, the turbine will fall (due to gravity) and there will be no substructure to react to motion of the tower base / platform; disabling the platform will cantileve...
by Jason.Jonkman
Tue Aug 11, 2020 10:02 am
Forum: Testing
Topic: Error running HydroDyn file
Replies: 12
Views: 4746

Re: Error running HydroDyn file

Dear Ka.Chang, Here are my answers to your questions: 1) By "no waves", do you mean still water or no water? To model still water, enable HydroDyn (CompHydro = 1) and set WaveMod = 0. To eliminate the water (and buoyancy), disable HyrdoDyn completely (CompHydro = 0). 2) Similarly, by "...
by Jason.Jonkman
Tue Aug 11, 2020 6:53 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST theory manual
Replies: 322
Views: 48850

Re: FAST theory manual

Sent.
by Jason.Jonkman
Mon Aug 10, 2020 10:34 am
Forum: Computer-Aided Engineering Software Tools
Topic: Wind/Wave PropagationDir
Replies: 8
Views: 1799

Re: Wind/Wave PropagationDir

Dear Rachael,

Yes, that is correct. That said, FAST / OpenFAST does not explicitly ues the compass direction, and so, has no knowledge of north/south/east/west.

Best regards,
by Jason.Jonkman
Mon Aug 10, 2020 10:07 am
Forum: Computer-Aided Engineering Software Tools
Topic: Wind/Wave PropagationDir
Replies: 8
Views: 1799

Re: Wind/Wave PropagationDir

Dear Rachael, I would say that PropagationDir in InflowWind defines the wind direction and WaveDir in HydroDyn defines the wave direction, but--as you said, PropagationDir is defined clockwise from above and WaveDir is defined anti-clockwise from above. Zero degrees for both means that the wind and ...
by Jason.Jonkman
Mon Aug 10, 2020 6:56 am
Forum: Controls
Topic: im a Beginner to Simulink and FAST V8
Replies: 6
Views: 188

Re: im a Beginner to Simulink and FAST V8

Dear Rui.Hao,

A similar question has been asked and answered here: viewtopic.php?f=4&t=1300&p=5680. Yes, we try to answer questions, but please search (in the upper right) before asking.

Best regards,
by Jason.Jonkman
Fri Aug 07, 2020 7:13 am
Forum: Controls
Topic: im a Beginner to Simulink and FAST V8
Replies: 6
Views: 188

Re: im a Beginner to Simulink and FAST V8

Dear Rui.Hao, The basic operation of the FAST v8 interface to Simulink is discussed in the old FAST v7 User's Guide (https://drive.google.com/file/d/1d_-vRRK3sXlunf1I1tDmtSWUveed91gg/view?usp=sharing), with updates discussed in the FAST v8 ReadMe file (https://drive.google.com/file/d/17LDwMnCVmLfbRW...
by Jason.Jonkman
Fri Aug 07, 2020 7:09 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST theory manual
Replies: 322
Views: 48850

Re: FAST theory manual

Sent.
by Jason.Jonkman
Thu Aug 06, 2020 5:08 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Verify FAST v8 linearization result
Replies: 4
Views: 125

Re: Verify FAST v8 linearization result

Dear Xiao, Just a couple comments: ⋅ OK, I think I'm starting understand your nomenclature and equations. But keep in mind that Te (electrical generator torque) may depend on the generator speed, omega_r (depending on how you are linearizing) and Tt (the aerodynamic torque) is likely gener...
by Jason.Jonkman
Thu Aug 06, 2020 1:57 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Verify FAST v8 linearization result
Replies: 4
Views: 125

Re: Verify FAST v8 linearization result

Dear Xiao, A couple comments: ⋅ What is the source of your model.png image? I'm not sure I follow all of the nomenclature, nor why the (3,3) term would be zero -- the generator acceleration could be impacted by the aerodynamic or generator torque. ⋅ The accuracy of the linear mod...
by Jason.Jonkman
Thu Aug 06, 2020 1:45 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Bmodes download
Replies: 5
Views: 166

Re: Bmodes download

Hi Florence,

I would guess you just have a numerical round-off problem. Checking the first set of coefficients for the fore the first tower fore-aft mode, the sum of the coefficients is 0.99, not 1.

Best regards,

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