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