Modify STC code of OpenFAST: Which code should I modify

[QB-Lin]

I hope to modify the source code of OpenFAST
I hope to add the parameter "BladeIndex" to classify the wind load on different blade in STC module
So I need to add these:
Let the code get the BladeIndex Parameter from dat file, so I need to change the code that control the parameter reading of OpenFAST
Let the STC code add different load based on blade index. So I need to change the blade load module in STC
Could you show me the file relating to these modification?

[jjonkman]

Dear @QB-Lin,

For blade-based structural controllers (StCs), one instance of StC is created for each StC on each blade. But none of these instances of StC know from which blade it is located on; rather, this information is tracked by ServoDyn. You'd have to change the source code so that StC knows which blade it is on and uses different input files for each blade.

NREL has not done this ourselves, and so, cannot provide step-by-step guidance. But I would start by reviewing how ServoDyn generates and tracks the distinct instances of StC.

Best regards,

[andrew-platt]

Dear @QB-Lin,

Which version of OpenFAST are you using? We had an internal request for the same feature recently. I have a few ideas on a very quick way to make this option work.

Regards,

[andrew-platt]

Dear @QB-Lin,

We are adding this feature to an upcoming 4.2 release (later this month). If you would like to try it out now, take a look at this branch: https://github.com/mayankchetan/openfast/tree/v410_multipleBladeStC

To use this, add additional force time series input file names in the BStC input file. So for example, you can add a prescribed force to only blade 2 as follows:

---------------------- PRESCRIBED TIME SERIES --------------------------------- [used only when StC_DOF_MODE=4]
          2   PrescribedForcesCoord- Prescribed forces are in global or local coordinates (switch) {1: global; 2: local}
"Bld-NoForce.dat"             PrescribedForcesFile   - Time series force and moment (7 columns of time, FX, FY, FZ, MX, MY, MZ)
"Bld-TimeForceSeries_Fy.dat"  PrescribedForcesFile   - Time series force and moment (7 columns of time, FX, FY, FZ, MX, MY, MZ)
"Bld-NoForce.dat"             PrescribedForcesFile   - Time series force and moment (7 columns of time, FX, FY, FZ, MX, MY, MZ)
-------------------------------------------------------------------------------

where the Bld-NoForce.dat files contain no forces like this:

# Time,     Fx,      Fy,      Fz,      Mx,      My,      Mz
# (s)       (N)      (N)      (N)      (N-m)    (N-m)    (N-m)
0.0         0.0      0.0      0.0      0.0      0.0      0.0
90.         0.0      0.0      0.0      0.0      0.0      0.0

If you then want to include different prescribed forces on each blade, add 3 BStC instances with the only the corresponding blade has active forces.

Hopefully this helps with your project,