计及风剪效应的垂直轴风力机叶片倾角优化

Optimization of blade dip angle for vertical axis wind turbine considering wind shear effect

风剪效应易使垂直轴风力机叶片受到的载荷不均匀,造成叶片产生振动及疲劳损坏。针对一种1. 5 MW H型对称翼垂直轴风力机,采用双致动盘多流管理论分析不同倾角下对应叶片的受力情况;以叶片倾角优化前后的风功率相等为目标函数,对叶片倾角进行优化计算。提出采用方差评价叶片受力不均的衡量方法。结果表明:风轮运行一周过程中,风剪效应对叶片载荷的影响主要集中在法向力载荷上。对于该1. 5 MW风力机,最优叶片倾角为-7°。经过倾角优化后,一周内表征受力不均匀的最大方差由1. 53降到0. 96,方差平均值由0. 66降到0. 52,垂直轴风力机叶片受力情况得到明显改善。

The wind shear effect makes the load applied on the vertical axis wind turbine blade uneven,which causes vibration and fatigue damage to the blade.For a kind of 1.5 MW H-type vertical axis wind turbine with symmetrical wing,we adopt the theory of double-disk multiple stream tubes to perform the force analysis on the blade with different dip angles.The wind power equivalence before and after optimization is viewed as the objective function,and the optimal calculation is conduced on the blade dip.The variance method is adopted to evaluate the uneven stress distribution of the blade.The results show that the effect of the wind shear on the blade is mainly on the normal force in the process of wind wheel running.For the 1.5 MW wind turbine,the optimal dip angle is-7 degrees.After the dip angle optimization,the maximum variance in a cycle decreases from 1.53 to 0.96,the average variance decreases from 0.66 to 0.52,and the stress distribution of the wind turbine s blade is improved obviously.