Hi,
Im currently trying to come up with a method for determining the angle of attack for a vertical axis wind turbine that is pitched (where omega R is not acting along the chord line) but so far to no avail, its been reckoning my head for a couple of weeks now,

I know for a fixed bladed its fairly straight forward to determine alpha, its just atan ((Vasin theta)/(va Cos theta +omegaR))

my problem is when Omega R is no longer acting on the chord line how does one go about determining alpha?

Thanks and help would be very much appreciated.