Hello to all, I need a airfoil polar for a "simple" calculation of a characteristic power curve for a wind energy converter. The problem is that the polar has to yield datas for angles of attack up to 30 degrees, in a region lying far in stall condition. Of course I don't want to have exact datas, but a facility to approximate ca and cw roughly. The airfoil I want to get datas for is the FX63-137. I have a measured polar from
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which is providing data up to an angle of attack of +12 degrees. Reynolds number is located from 300000 up to 500000. Calculations, f.e. with Xfoil, result on the one hand in quite realistic cw numbers, on the other hand in much too high ca numbers, at 30 degrees f.e. 1.6-1.7. There must at least be a approximation for a planar plate, or am I wrong?Thanks for your attention, Michael