[mohammad]

Hi guys;
I have a question . I'm working on a CFX model of a wind turbine. I have got some results and now I want to plot the Cp.
be cause the blades is tapered and has a twist angle and so different AOA at different radial positions , I want to know that which coordinate system should i choose for plotting the pressure coefficient. Global x direction or I MUST choose local one with the "X" axis along the chord length.????
Please pay attention that if I use Global coordinate system when I have AOA, two point at the same Global X position don't have the same local X positions??? and the Cp always is plotted according to "x/C"....but which "x"?:help:

See the attached picture and see what I mean for the effect of rotation...plz