Hi, i have a question related to Simulink. i would like to know, how can i exert an external force F, which is generated by a user-defined block in Simulink, on an arbitrary point of tower in each time step? and whether force F must be specified in OutList or not?
Thanks
Dear Milad,
In the latest version of FAST, FAST v7.00.01a-bjj, the only way to exert an external force on arbitrary tower points is through the user-defined routien UserTwrLd(). Without a modification to the FAST-Simulink interface, it is not possible to calculate such forces from Simulink.
I’ve attached a FAST platform input file that will do nothing more than enable your model to call user-defined routine UserTwrLd(). To use the attachment with FAST v7.00.01a-bjj, simply set PtfmModel to 2 and PtfmFile to “Platform_UserTwrLd.txt” in your FAST primary input file. Then, “all” you will need to do is implement your own tower-loading calculations within routine UserTwrLd(). Routine UserTwrLd() can be used to calculate loads applied to the tower in any form (aerodynamics, hydrodynamics, soil, etc.). The forces calculated in routine UserTwrLd() should include all terms that you want that are not presently accounted for FAST (FAST accounts for mass, inertia, gravity, loads transmitted from the rotor, etc.). A placeholder for routine UserTwrLd() is given at the bottom of source file HydroCalc.f90. Changing routine UserTwrLd will require a recompile of FAST.
I hope that helps.
Best regards,
Platform_UserTwrLd.txt (6.14 KB)
Dear Mr.Jonkman
I really appreciate your prompt response,
Actually,i am trying to exert the external force F, on arbitrary tower point of an ITI energy barge with a 5 MW baseline wind turbine. would you provide me with a solution to exert such a force on arbitrary tower point of a floating platform?
thanks
Dear Milad,
FAST v7.00.01a-bjj is not currently set up to support loading on the tower for a floating wind system. I don’t think the changes will be difficult, but changes will be required in the source code to implement this. If you choose to do this yourself, I suggest you look in routine FAST.f90/TwrLoading where routine UserTwrLd is called.
We are currently working on an updated version of FAST. This version will include the option to include both tower and platform loading at the same time.
I hope that helps.
Best regards,
Dear Mr.Jonkman
thanks for your great advise.
Best Regards
Dear Mr.jonkman
i tried to compile FAST v7.00.01a-bjj by “Compile_FAST” Batch file. i changed the files locations in “Compile_FAST” Batch file and let it run. but i have blocked by the errors which can be seen in the attached file.
thanks
Dear Milad,
It looks like there are some errors in the path names you specified. For instance, the IVF_LOC and IVF_LOC1 variables start with "C:C:" instead of just "C:". Try removing the extra “C:” and see if that works.
Regards,
Bonnie
thanks, i think i must pay more attention to what i change…
Best Regards,
Milad.