Confusion about the output of FAST V7

Hi all,

I have a confusion about the FAST v7. Actually, I want to know the wind speed of 3/4 blade. However, the wind speed input generated by TurbSim is at the hub height. So the wind speed output of FAST V7 WindVxi is at the hub height. How can I know the wind speed value of 3/4 blade based on the wind speed of hub height? Is there any related output of wind speed value of 3/4 blade? Thanks a lot.

All the best.

Yanhua

Dear Yanhua,

Actually, TurbSim generates wind speeds at multiple points across the rotor plane.

However, in FAST v7, there is no option for outputting wind speeds at user-specified locations without modifying the source code.

If you upgrade to FAST v8, the InflowWind module allows the user to identify multiple locations where wind can be output. Moreover, in AeroDyn v15, the user can output the undisturbed wind speeds at each blade analysis node.

Best regards,

Dear Jason,

Thanks for your reply. I checked the InflowWind module (NRELOffshrBsline5MW_InflowWind_12mps.dat) used by Test18.fst in FAST 8. But I am not sure how to change it to add some other locations of wind speed. I think I should variable ‘‘NWindVel’’ from 1 to 2 (for example). How to define the locations in the InflowWind module? What does “WindVxiList”,’'WindVyiList" and “WindVyiList” mean? Should i add the corresponding outputs in the OUTPUT? The part of the InflowWind module (NRELOffshrBsline5MW_InflowWind_12mps.dat) is shown as follows.

3 WindType - switch for wind file type (1=steady; 2=uniform; 3=binary TurbSim FF; 4=binary Bladed-style FF; 5=HAWC format; 6=User defined) 0 PropagationDir - Direction of wind propagation (meteoroligical rotation from aligned with X (positive rotates towards -Y) -- degrees) 1 NWindVel - Number of points to output the wind velocity (0 to 9) 0 WindVxiList - List of coordinates in the inertial X direction (m) 0 WindVyiList - List of coordinates in the inertial Y direction (m) 90 WindVziList - List of coordinates in the inertial Z direction (m) ..... ====================== OUTPUT ================================================== False SumPrint - Print summary data to <RootName>.IfW.sum (flag) OutList - The next line(s) contains a list of output parameters. See OutListParameters.xlsx for a listing of available output channels, (-) "Wind1VelX" X-direction wind velocity at point WindList(1) "Wind1VelY" Y-direction wind velocity at point WindList(1) "Wind1VelZ" Z-direction wind velocity at point WindList(1)

Thanks very much for your help!

All the best.
Yanhua

Dear Yanhua,

To add additional wind output locations, increase NWindVel and add addition values for WindVxiList, WindVyiList, and WindVziList, which are the global X,Y,Z locations of the output location. See the InflowWind User’s Guide for more information: wind.nrel.gov/nwtc/docs/InflowWind_Manual.pdf.

Best regards,