切出风速下风力机变桨故障叶片气动特性及准静态结构响应分析

为探究大型水平轴风力机达到切出风速停机后变桨故障叶片的气动特性及准静态结构响应，基于计算流体力学方法对NREL 5 MW风力机变桨故障/成功叶片气动侧状态进行分析，并利用双向弱流固耦合及曲屈分析对典型方位角下变桨故障叶片展开研究。结果显示：切出风速下变桨故障叶片挥舞力矩平均值为变桨成功叶片的13.8倍，且前者的流场尾迹更为明显。此外，180°方位角变桨故障叶片较之0°方位角变桨故障叶片应力及叶尖位移分别减小29.8%和32.7%，一阶屈曲因子增加20.2%。

Aerodynamic characteristics and quasi-static structural response of the blades with pitch fault in a wind turbine at the cut-out wind speed

To investigate the aerodynamic characteristics and quasi-static structural response of the blades with pitch fault in a large horizontal axis wind turbine under the cut-out wind speed and shutdown condition, aerodynamic status of the blades under fault/normal status of pitch system in NREL 5 MW wind turbine were analysed basing on computational fluid dynamics method, and the blades with pitch fault under typical azimuths were studied using two-way weak fluid-structure coupling and buckling analysis. The results show that average flapwise moment of a blade with pitch fault is 13.8 times as that under normal status at cut-out wind speed, and flow field wake of the former is more obvious. In addition, stress and tip displacement of a blade with pitch fault under 180° azimuth are 29.8% and 32.7% lower than those under 0° azimuth, respectively, while the first-order buckling factor increases by 20.2%.