DiskVel

[Marc.Bromm]

Hello,

working on the coupling of a program with FAST I am stuck at one more thing that I am totally not sure about - the DiskVel function.
It calls the function WindInf_ADhack_diskVel that returns some type of mean velocity (FF_wind → overall mean, HH_wind → some interpolated value between two timesteps, …).

Position = (/0.0, 0.0, HH /) AvgInfVel(:) = WindInf_ADhack_diskVel( REAL(Time, ReKi), Position, ErrStat )

I guess my case is closest to FD_Wind because I get the velocities for every point FAST needs (blades nodes and hub height) always in the current time step. It is ok to just calculate the mean out of all those velocities for every time step? What would you recommend. What is this value actually for?

Kind regards

Marc

[Jason.Jonkman]

Dear Marc,

Yes, DiskVel is used to calculate an “approximate” rotor-disk-averaged velocity, with components both normal and tangential to the rotor. This velocity is needed in several aerodynamic calculations, such as the generalized dynamic wake and skewed-wake correction.

I’m not sure what are doing, so, I’m not sure how to offer you recommendations.

Best regards,

[Marc.Bromm]

I get the velocities at the blade elements out of a LES simulation. So I guess I can just use the average of all the velocities of one step in my simulation.

Best regards