FAST V7 Rotor averaging

Many thanks for FAST V7, I am using it in my masters thesis to investigate the yaw misalignment in free-yawing wind turbines.

Is HorWndDir a single point value or rotor averaged? If rotor averaged, what is the averaging time value?

I have scoured the FAST source code, however my Fortran capabilities leave a lot to be desired and I was not able to find a conclusive answer.

Many thanks in advance!

Best wishes,


Dear Lukas,

FAST v7 output HorWndDir (which is not an output available from FAST v8 or OpenFAST), reported the instantaneous horizontal wind direction of the undisturbed wind inflow at a single point–in this case, the point being located at hub height at the undisplaced tower centerline.

Best regards,