Analysis of a Two Bladed Wind Turbine under Random Loading

Abstract

This work is focused in the study of the dynamic behavior of a two bladed wind turbine, considering random wind loading. The aerodynamic forces actuating over the blades are calculated using a simple approach, assuming that both, the fluctuation of the wind speed incident on the airfoil and pitch angle have a linear relation with the resultant loadings meaning that variations in lift and drag forces can be approximated by an affine transformation at a given point of operation. The nacelle and rotor blades are considered rigid bodies mounted in a flexible tower. All movements, except for the inplane rotation of the rotor, are considered small so that a linear approach can be applied. Based on this model, the calculation of stochastic stresses in critical spots over the structure is performed.