I am running NREL 5MW cases with different setting in its AeroDyn primary file. My desired output are the AoA, Cl, Cd, and Vrel (relative wind speed) at all 9 nodes of the blade.
The wind condition is power-law wind profile at 10 m/s (at the hub height) and 0.14 power-exp.
In the AeroDyn primary file, WakeMod = 1, AFAeroMod = 1, TwePotent = 0. SkewMod is either 1 or 2 (1 stands for uncoupled, 2 stands for Pitt/Peter’s model). All other parameters are default.
In the cases of SkewMoD =1, the B1N9Vrel, B2N9Vrel, B3N9Vrel are constantly zeros throughout the 30 sec. FAST simulation. In other words, it indicates that relative wind speeds at the blade tips are zero. From my understanding of wind turbine aerodynamics, the relative wind speed supposes to be the highest at the tip. Please correct me if I am wrong.
In the cases of SkewMoD =2, the B1N9Vrel, B2N9Vrel, B3N9Vrel are NOT zeros anymore. The values of nodal Vrel gradually increase from the node 1 to node 9 of the blade. The relative wind speeds in other nodes (node 1~8) do not have large changes comparing to the cases of SkewMoD =1.
Therefore, my question is what SkewMoD I should use to have a good result on the rotor aerodynamics for a non-skewed inflow or even a skewed inflow.
If both SkewMod are feasible, is there any way to solve the problem of zero Vrel at the blade tip for the cases of SkewMoD =1?