[color=blue]Hi everybody,
I am learning AirfoilPrep and have some understanding questions.

The tables of airfoil characteristics (AOA CL CD CM) are measured in wind tunnels. So they could be augmented by 3DStall function of AirfoilPrep. Rotor R means TipRad?How to choose Alpha End? Rpm and wind speed are average rated values?

The 3D table results could now be extended in TableExtrap. Is Aspect Ratio= (Span^2)/Area also right for wind turbine blade? I do not know how to estimate the AR of tapered and twisted blade? Is Max CD looked up from the red table? or Just use the calculated value from AR.

The same input table as TableExtrap is used to calculate dynamic stall parameters. We choose stall angle from the CL column. How to understand " Cn at stall value for negative angle of attack" ?
Thanks
Best regards