Yaw controlled by torque

Dear all,

I’m trying to emulate a quadratic damping yaw system. In my simulation i am enabling the Yaw degree of freedom in elastodyn and setting YCMODE=5, the spring/damper parameters are all set to 0. In my bladed style dll i’m setting parameter 29 (starting from 1) to 1 and parameter 41 to 1e9Nm. This is for testing, my plan is to set a torque value depending on the yaw rate squared.

What i see is the same behavior independently of the torque level i command.

I have seen that in the manual (readthedocs) there is an explanation for parameter 41:

41 ← demanded yaw actuator torque [this output is ignored since record 29 is set to 0 by ServoDyn indicating yaw rate control

Is it that demanding yaw torque is not supported by OpenFast?

Thanks in advance and Kind regards


Dear @Roberto.Echeverria,

That appears to be the case, but I don’t believe there is any reason why this feature would not be supported by OpenFAST. It looks like with small update to the source code, it is possible to accept the yaw torque command from Bladed-style DLL controllers.

Best regards,