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Couple OpenFAST and CFD code

Posted: Tue Apr 30, 2019 8:07 am
by Bingjun.Luo
Hello! I am not familiar with OpenFAST but I am quite familiar with STAR-CCM+, a CFD code. My project is to couple OpenFAST and STAR-CCM+ to analyse hydrodynamic behavior of wind turbine semi-platform under the wave environment. I describe my problem in detail below.

I want to analyse hydrodynamic behavior of wind turbine semi-platform under the wave environment. At the beginning, I use STAR-CCM+ to calculate the loads of wave acting on the platform in the first time step. Then I want to transfer these loads to OpenFAST to calculate the responses (e.g. dispalcement ) of platform in the first time step. Maybe it's the ElatoDyn module to do this calculation. After calculating the responses in OpenFAST, I want to transfer these responses to STAR-CCM+, so that STAR-CCM+ can calculate the loads acting on the platform in the second step by appling the responses data from OpenFAST. Then the loads are transferred to OpenFAST again to calculate the responses of the platform. Loads and responses transferring continues each time step till the maximum modeling time is reached. The process can be seen in the attached picture below.

For the time being, I can export the loads data, forces and moments acting on the center of mass of the platform in three directions, from STAR-CCM+. I want to find the way to transfer these loads data to OpenFAST so that it can do the calculation of responses.
It seems that my coupling of OpenFAST and STAR-CCM+ is to replace the HydroDyn module in OpenFAST. May I should find the place where loads are transferred between HydroDyn and ElastoDyn.

My questions are:
1. Is it possible to couple OpenFAST and STAR-CCM+ in the way I mention above? How difficut is it?
2. If possible, where is the position, in which loads and responses are transferred between ElastoDyn and HydroDyn, or the position which control loads and responses between the two modules. Then I can replace the loads data with that from CFD code?
3. Are there any documents about OpenFAST that can help me do this coupling?
4. I am a master of civil engineering and it's my second years in school. I know little about programming language. Is it possible for me to couple OpenFAST and STAR-CCM+ in the way I mention above? Is there enough time for me because I have only another one year before my graduation?

I wish your answer! Thank you very much!

Re: Couple OpenFAST and CFD code

Posted: Tue Apr 30, 2019 4:42 pm
by Jason.Jonkman
Dear Bingjun.Luo,

I see you asked the same question here and on OpenFAST issues (https://github.com/OpenFAST/openfast/issues/282). I've responded to your questions in OpenFAST issues. This forum tends to focus on usage of FAST / OpenFAST whereas as OpenFAST issues better serves the OpenFAST source-code development community.

Best regards,

Re: Couple OpenFAST and CFD code

Posted: Wed May 01, 2019 1:38 am
by Bingjun.Luo
Dear Jascon.Jonkman,
I have already your answer. Thank you very much!
I ask my question here because I want to know more ohter people's suggestions about the question, especially the people know both the two software. It's very difficult question for me and I need more help.
I am sorry to bother you.