Dynamic response analysis of the rotating blade of horizontal axis wind turbine

This paper presents a dynamic response analysis of the blade of horizontal axis wind turbines using finite element method. The blade is treated as a cantilever and modeled with two-node beam element. The blade element-momentum theory is applied to calculate the aerodynamic loads. Dynamic inflow and dynamic stall are taken into account to reflect the transient aerodynamics. The centrifugal stiffening is introduced to consider the restoring effects of centrifugal force. An aerodynamic damping model is presented for calculating the overall damping ratio instantaneously during time-domain simulation. The structural dynamic equation is solved using Newmark method and the overall dynamic response of the blade is obtained based on the modal superposition principle. Applying the proposed method, the power production load case of a 1.0 MW wind turbine operating in turbulent wind field is simulated. The simulation results indicate that the blades of large-scale horizontal axis wind turbines undergo significant vibration and deflection during operation, and the centrifugal stiffening and aerodynamic damping both considerably affect the structural response of the blade.