风轮不平衡载荷下超大型风电机组叶片颤振极限研究

STUDY ON FLUTTER LIMIT OF ULTRA-LARGE WIND TURBINE BLADES UNDER ROTOR IMBALANCE LOADS

以IEA Wind 15 MW参考风电机组为研究对象,基于非线性时域气弹耦合分析工具,研究风剪切、偏航入流、质量不平衡3种不平衡载荷单一或共同作用时,超大型风电机组叶片的颤振极限。结果表明,单一不平衡载荷作用时,风剪切和±15°以内的偏航角会增大临界颤振速度,而质量不平衡会降低临界颤振速度,且质量偏重时颤振速度下降更加明显。3种不平衡载荷共同作用时,临界颤振速度的最大值和最小值都出现在剪切系数为0.3时;最大值总是在偏航角为非负值时取得,最小值在偏航角为-20°时取得;质量不平衡对临界颤振速度的影响与其单一作用时的规律一致。因此,在进行气弹稳定性分析时,应考虑多种风轮不平衡载荷共同作用,尤其是叶片质量偏重和偏航角度为-20°时这种最不利的情况。

This study focuses on the IEA Wind 15 MW Reference Wind Turbine and investigates the flutter limit of ultra-large wind turbine blades under imbalanced loads such as wind shear,yaw inflow,and mass imbalance.The results show that under a single unbalonced load,both wind shear and yaw misalignment within±15°increases the critical flutter speed.Conversely,mass imbalance reduces the critical flutter speed,and the flutter speed is decreased more obviously under heavy mass.When all three imbalanced loads act simultaneously,the critical flutter speed exhibit maximum and minimum values at a shear coefficient of 0.3.The maximum value consistently occurs at a non-negative yaw angle,while the minimum value is observed at a yaw angle of-20°.The impact of mass imbalance on the critical flutter speed is consistent with that of single unbalanced load action.Therefore,it is crucial to consider the combined effects of multiple rotor imbalanced loads,particularly in the unfavorable scenario of heavier blade mass and a yaw angle is-20°,when conducting aeroelastic stability analysis.