  This work presents an investigation on different methods for the calculation
of the angle of attack and the underlying induced velocity on wind turbine
blades using data obtained from three-dimensional Computational Fluid Dynamics
(CFD). Several methods are examined and their advantages, as well as
shortcomings, are presented. The investigations are performed for two 10MW
reference wind turbines under axial inflow conditions, namely the turbines
designed in the EU AVATAR and INNWIND.EU projects. The results show that the
evaluated methods are in good agreement with each other at the mid-span, though
some deviations are observed at the root and tip regions of the blades. This
indicates that CFD results can be used for the calibration of induction
modeling for Blade Element Momentum (BEM) tools. Moreover, using any of the
proposed methods, it is possible to obtain airfoil characteristics for lift and
drag coefficients as a function of the angle of attack.
