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by Jason.Jonkman
Thu Jun 24, 2021 9:51 am
Forum: Computer-Aided Engineering Software Tools
Topic: parallel computing with MATLAB
Replies: 1
Views: 14

Re: parallel computing with MATLAB

Dear Zhiheng, I'm not familiar with parallel computing in MATLAB, but it sounds like you have two (or more) processes trying to write to the same output file ( 5MW_OC4Semi_WSt_WavesWN.SFunc.ech , located in your E:\OPENFAST\r-test-master-2.4\cases\5MW_OC4Semi_WSt_WavesWN directory) at the same time....
by Jason.Jonkman
Thu Jun 24, 2021 9:39 am
Forum: Computer-Aided Engineering Software Tools
Topic: Hydrodyn standalone
Replies: 5
Views: 62

Re: Hydrodyn standalone

Dear Nicolas, The potential flow solution of HydroDyn only supports a linear stiffness matrix. In OpenFAST v2.6 and newer, the strip-theory solution computes the hydrostatic loads on the strip-theory members based on the time-dependent position/orientation of the floater, and so, this solution can i...
by Jason.Jonkman
Wed Jun 23, 2021 10:11 am
Forum: Structural Analysis
Topic: A problem about the effect of centrifugal force in ElastoDyn
Replies: 3
Views: 17

Re: A problem about the effect of centrifugal force in ElastoDyn

Dear JiYuan,

Yes, that is correct. The blade kinematics include the rotor speed and many other terms.

Best regards,
by Jason.Jonkman
Wed Jun 23, 2021 8:46 am
Forum: Structural Analysis
Topic: A problem about the effect of centrifugal force in ElastoDyn
Replies: 3
Views: 17

Re: A problem about the effect of centrifugal force in ElastoDyn

Dear JiYuan, Correct, the centrifugal stiffness calculated within SUBROUTINE Coeff() of ElastoDyn is computed locally, only for the purposes of estimate natural frequencies and damping. The actual centrifugal stiffness calculated by ElastoDyn as part of the time-domain solution is implemented throug...
by Jason.Jonkman
Wed Jun 23, 2021 7:44 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST theory manual
Replies: 383
Views: 84427

Re: FAST theory manual

Sent.
by Jason.Jonkman
Wed Jun 23, 2021 6:16 am
Forum: Computer-Aided Engineering Software Tools
Topic: Changing water depth for DeepCwind Model etc.
Replies: 46
Views: 2977

Re: Changing water depth for DeepCwind Model etc.

Andre,

You can find the Waves.f90 source file of the HydroDyn module in the OpenFAST source code: https://github.com/OpenFAST/openfast/bl ... /Waves.f90.

Best regards,
by Jason.Jonkman
Tue Jun 22, 2021 5:24 pm
Forum: Controls
Topic: Processing linearization output to obtain PID controller coefficients
Replies: 9
Views: 111

Re: Processing linearization output to obtain PID controller coefficients

Dear Jannik,

Yes, that sounds correct.

Best regards,
by Jason.Jonkman
Tue Jun 22, 2021 4:44 pm
Forum: Computer-Aided Engineering Software Tools
Topic: questions about running in linux
Replies: 2
Views: 29

Re: questions about running in linux

Dear Zhiheng, The "w" in the extension of FAST_SFunc.mexw64 is for "Windows", so, this binary file cannot be used on Linux. You must compile the OpenFAST S-Function, the OpenFAST dynamic library, and the MAP++ for use on Linux, as documented here: https://openfast.readthedocs.io/...
by Jason.Jonkman
Tue Jun 22, 2021 4:04 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Changing water depth for DeepCwind Model etc.
Replies: 46
Views: 2977

Re: Changing water depth for DeepCwind Model etc.

Dear Andre,

I do have a copy, but IEC 61400-3 (2008) is copyrighted, so, I cannot share it publicly.

Best regards,
by Jason.Jonkman
Tue Jun 22, 2021 4:00 pm
Forum: Controls
Topic: Processing linearization output to obtain PID controller coefficients
Replies: 9
Views: 111

Re: Processing linearization output to obtain PID controller coefficients

Dear Jannik, I'm glad you better resolved the "spike" which now results in a zero mean for A(2,1). I agree that column 9 in the standard inputs is collective blade-pitch, which sounds like the input you need. I'm not sure understand enough about what you are doing to be able to answer your...
by Jason.Jonkman
Tue Jun 22, 2021 8:59 am
Forum: Computer-Aided Engineering Software Tools
Topic: Hydrodynamic coefficients HELP!
Replies: 34
Views: 1657

Re: Hydrodynamic coefficients HELP!

Dear Bartosz, The second-order difference-frequency solution can cause both mean and low-frequency loading of the structure, resulting in both mean-drift and slow-drift response. But I don't recall seeing much second-order difference-frequency response on the Hywind spar due to the low level of load...
by Jason.Jonkman
Tue Jun 22, 2021 7:35 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST theory manual
Replies: 383
Views: 84427

Re: FAST theory manual

Sent.
by Jason.Jonkman
Tue Jun 22, 2021 6:01 am
Forum: General
Topic: FAST.Farm
Replies: 225
Views: 31699

Re: FAST.Farm

Dear Li, I'm not sure what is holding up the release of OpenFAST v3.0.0, which will include FAST.Farm, but you don't need to wait for that to start using FAST.Farm. The links to the FAST.Farm source code, documentation, and sample models are included in the forum posts above within this topic. Best ...
by Jason.Jonkman
Mon Jun 21, 2021 2:20 pm
Forum: Computer-Aided Engineering Software Tools
Topic: FAST theory manual
Replies: 383
Views: 84427

Re: FAST theory manual

Sent.
by Jason.Jonkman
Mon Jun 21, 2021 10:00 am
Forum: Controls
Topic: Processing linearization output to obtain PID controller coefficients
Replies: 9
Views: 111

Re: Processing linearization output to obtain PID controller coefficients

Dear Jannik, From what I can see, the average value does look close to zero except for the presence of "spikes" at 60, 180, and 300 degrees azimuth, which I presume are associated with with the tower influence model. My guess is that the mean will get close to zero if the tower influence m...

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