非线性对不同尺寸长柔叶片动态响应的影响OA

To investigate the impact of geometric nonlinearity on the response of wind turbine blades of different sizes,a blade nonlinear dynamic response analysis method was constructed based on the geometrically exact beam theory(GEBT)and the blade element momentum theory considering geometric nonlinear effects.The numerical accuracy of GEBT for beam nonlinear deformation and the dynamic response of the full-size wind turbine was validated using a cantilever beam example and the IEA 15 MW wind turbine example,respectively.Afterwards,5～22 MW wind turbines were taken as the research objects,and the linear and nonlinear methods were used to analyze the response of wind turbines under steady wind and turbulent wind conditions,respectively.The results show that under steady wind conditions,after considering the geometric nonlinearity,the turbine power near the rated wind speed has a deviation of 0.001 2%,2.13%and 4.79%respectively compared with the results of the linear method;the blade tip flapping displacement deviations are 0.73%,10.24%and 21.68%respectively.Under turbulent wind conditions,the maximum energy deviations of the flapwise tip deflection,the flapwise root moment and the edgewise root moment of the 22 MW wind turbine in the low-frequency region are 51.77%,63.52%,and 40.25%,respectively.Geometric nonlinearity has a significant impact on the calculation of blade loads and power of large wind turbines,and nonlinear methods are more suitable for dynamic response analysis of large wind turbines.