The influence of wind shear on vibration of geometrically nonlinear wind turbine blade under fluid-structure interaction

For the large-scale offshore wind turbine blades, the governing equations in fluid domain and the motion equations in structural domain with geometric nonlinearity were developed based on ALE description, and the corresponding discrete equations were obtained. Blade entity model was built up using Pro/E, and the blade vibration characteristics under fluid-structure interaction (FSI) were simulated using ANSYS. Numerical results show that wind shear effect greatly increases the peak values of response curves for displacement and stress, makes the effect of bi-directional fluid-structure interaction (BFSI) more obvious, and also accelerates the attenuation of vibration curves. The displacement of blade airfoil increases nonlinearly along the span direction, and reaches the maximum at the blade tip. The maximum Mises stress appears in the middle of the blade, and reduces gradually towards each end of the blade. Furthermore, the contribution of wind shear effect (WSE) to displacement and Mises stress is much greater than that of FSI.