Dear @Jason.Jonkman ,
I was running simulation in OpenFast v2.1 including structural control.
If I want to fit the model, I need to get the acceleration of the mass block. OutListParameters only contain the displacement and velocity of the mass block, how can I output the acceleration
Could you please help me ?
Best regards,
Haodong Zhang
Dear @Haodong.Zhang,
Good point; the acceleration of the TMD is not currently output from the Structural Control (StC) submodel of ServoDyn. You could estimate it by computing the numerical derivative of the velocity, but numerical derivatives can introduce noise that you’d likely have to filter out. Alternatively, the acceleration is certainly computed internally with StC and you could always modify the source code to output this acceleration, but this would require a recompile of OpenFAST. You could also request a feature enhancement of OpenFAST through OpenFAST GitHub Issues so that this output is included in the standard release of OpenFAST, but I suspect it make take a while for NREL to get to this.
Best regards,
Dear @Jason.Jonkman ,
Thank you very much for your reply.
In substructure structural control, only TMD degrees of freedom in the X direction are allowed, should the value of StC_P_Z be positive or negative, and is the reference point the joint of the platform and the tower?
Best regards,
Haodong Zhang
Dear @Haodong.Zhang,
Just a couple comments:
StC_P_Z is the origin of the body that the StC is placed (blade root for blades, yaw bearing for nacelle, tower base for tower, and platform reference point for substructure). Given that, I would guess StC_P_Z would most likely be positive.Best regards,
Dear @Jason.Jonkman ,
Thank you very much for your reply.
Sorry, my expression is wrong, I only allowed TMD degrees of freedom in the X direction in the simulation.
Best regards,
Haodong Zhang