Dear @Jason.Jonkman ,
Please, I am very sorry for drawing back because I am running the FAST version instead of the Openfast version. I am using FAST because it is easier for me to deal with the Platform using stiffness matrices, which are determined from a program implemented in Matlab.
I was able to compile FAST_v7.02 after updating the UserPtfmLd in the UserSub-routine source code, and I ran the code successfully with the Platform model for onshore wind turbines activated in the FAST input file and enabling the PtfmSgDOF and PtfmSwDOF only in the platform input file.
- I am getting large values for the platform motion; for example, PtfmTDxi = 2.511E+02 metres at 40.013 sec simulation time. Is there anything I can do to get a much lower value?
- If I activate the platform degrees of freedom PtfmHvDOF (Platform vertical heave translation DOF (flag)) and PtfmPDOF (Platform pitch tilt rotation DOF (flag)) in the Platform input file, the simulation will terminate normally but with errors (see below). Do I need to make changes to any part of the source code for the simulation to run successfully? because it appears to me that the first two degrees of freedom (PtfmSgDOF and PtfmSwDOF) are default settings. Please, I need your support to resolve these errors. To what extent do the errors affect the results of the simulation?
I have checked previous related questions on the platform regarding errors similar to this one and the suggestions you provided (Small angle assumption violated in SUBROUTINE SmllRotTrans()), but I am still having difficulties resolving the errors.
Thank you
WARNING: Small angle assumption violated in SUBROUTINE SmllRotTrans() due to a large blade
deflection. The solution may be inaccurate. Simulation continuing, but future warnings will be suppressed.
Additional debugging message from SUBROUTINE SmllRotTrans(): 8.16 s
WARNING: High VNB velocity encountered during induction factor calculation.
Blade number 3, Element number 12 VNW = 8.3445, VNB = 101.06
WARNING: High VNB velocity encountered during induction factor calculation.
Blade number 3, Element number 12 VNW = 8.2769, VNB = 104.36
WARNING: High VNB velocity encountered during induction factor calculation.
Blade number 3, Element number 13 VNW = 7.5059, VNB = 102.5
WARNING: High VNB velocity encountered during induction factor calculation.
Blade number 3, Element number 11 VNW = 9.0877, VNB = 101.23
WARNING: High VNB velocity encountered during induction factor calculation.
Blade number 3, Element number 12 VNW = 8.2137, VNB = 107.35
WARNING: Induced velocity warning written 5 times. The message will not be repeated, though
the condition may persist.
Total Real Time: 19.882 seconds
Total CPU Time: 17.609 seconds
Simulated Time: 40.005 seconds
Time Ratio (Sim/CPU): 2.2718
FAST terminated normally.
Best regards
Kachallah Alhaji Kau