风力机最佳攻角与最大升阻比攻角非等同性研究

Non equivalence demonstration between optimum attack angle and maximum lift drag ratio of wind turbine

为提高风力机风能利用率,追求最大风能利用系数,对水平轴风力机最佳攻角与最大升阻比攻角的非等同性进行了理论分析,并采用叶素动量理论对其进行实例论证,以及通过计算流体力学(CFD)对结论进行仿真验证。研究结果表明,二者具有非等同性,最佳攻角略大于最大升阻比攻角,处于最佳工作点的风力机具有更高的风能利用系数,同时具有最大的速度比阈值区间。研究进一步发现,对于目前工作于最大升阻比攻角状态的风力机,通过减小叶尖速比的方式可以使其过渡到最佳攻角状态。

In order to further improve the utilization rate of wind energy and track the maximum wind energy utilization coefficient,optimum angle of horizontal axis wind turbine and the non-equivalence of maximum lift-to-drag ratio angle is demonstrated theoretically,and the example is expounded by element momentum theory,and the conclusion is further verified by computational fluid dynamics（CFD）. The results show that the two are not equal,and the optimal angle of attack is slightly larger than the maximum lift-to-drag ratio,the wind turbine has there are the maximum wind energy utilization factor and the maximum velocity ratio threshold region in wind turbine which is at the optimum angle of attack. And through the study found that for the current work in maximum lift-todrag ratio,the attack angle of the wind turbine can be transit to the optimum angle of attack by reducing the tip speed ratio. The wind turbine has there are the maximum wind energy utilization factor and the maximum velocity ratio threshold region in wind turbine which is at the optimum angle of attack.