旋转激振气流下风力机风轮振动及应力谐响分析

风力机叶片的断裂与运行过程中的振动密切相关。本文基于ANSYS谐响应分析法,对小型水平轴风力机在旋转激振气流作用下风轮振动的过程中,叶片表面的应力分布规律进行研究。结果发现：在额定工况下,叶片低阶振动的位移主要发生在挥舞方向上；各阶振动下应力最大的位置均出现在靠近前缘的气动中心线附近,一阶振动应力集中的区域出现在0.20R-0.58R,二阶振动时应力较大的区域出现在0.71R-0.79R,三阶振动时应力较集中的区域出现在0.79R-0.88R,但以一阶振动的应力最大；在低阶振动中,一阶振动时循环应力的往复拉压作用对叶片的影响最大,也是小型水平轴风力机叶片产生疲劳失效的主要诱因。

Analysis of vibration and stress harmonic response on wind turbine rotor under rotating excited airflow

The fracture of wind turbine blades is closely related to the vibration during the operation. Based on the harmonic response analysis method by ANSYS, the stress distributing regularity of the blade surface of small horizontal axis wind turbine is studied during the vibration of the wind wheel under the rotating excitation air flow. The results show that under the rated conditions, the displacement of blades in low order vibration is found in the direction of swing. The position of maximum stress under each vibration is closed to the leading edge of the aerodynamic center line. The stress region is concentrated in the range of 0.20 R-0.58 R in the first-order vibration, and is concentrated in the range of 0.20 R-0.58 R in the second-order vibration, and is concentrated in the range of 0.79 R-0.88 R in the third-order vibration, while the maximum stress is appeared in the first-order vibration. The blade is mainly affected by the reciprocating tension and compression of cyclic stress in the first-order vibration during the low order vibration, which is the main cause of fatigue failure of the small horizontal axis wind turbine blades.