[Diego_]

Hi everybody,
I have to analyze the performance of two counter-rotating VAWTs by using a UDF.
I've got a UDF for two turbines that rotate in the same direction (the anticlockwise direction, which is the positive direction in fluent).
My problem is changing the direction of one rotor to the clockwise direction in "C_CENTROID(x,c,t);".
I attach the UDF and the simplified version because I have to work in 2D.
Can someone help me?
Best regards
(p.s.: "alfapunto" is the derivative of alfa, the angle of attack)