大型风力机叶片涡流发生器流动控制的数值研究

Numerical study on the flow control of vortex generators on large wind turbine blades

介绍了风力机叶片涡流发生器建模方法,采用计算流体动力学(CFD)方法对S809翼型和某1.5 MW风力机叶片相对厚度为30%截面处的翼型进行数值研究,对比分析了涡流发生器的流动控制效果。计算结果表明,对于S809翼型,涡流发生器能够延迟失速攻角并提高翼型最大升力系数。在小攻角工况,涡流发生器由于自身的形状阻力会使翼型阻力有轻微增加;随着攻角的增加,涡流发生器由于其延缓分离的原因使翼型阻力减小。当攻角增大到17.21°以后,分离点已经前移到前缘20%c以内,涡流发生器没有起到减阻的效果。某1.5 MW风力机翼型由于其大厚度钝尾缘特征,使其具有良好的失速特性,涡流发生器增升减阻效果范围更广。研究可对实际风力机叶片涡流发生器流动控制提供理论依据。

In the introduction on the modeling method of vortex generators(VGs)on wind turbine blades,computational fluid dynamics(CFD)method was adopted to carry out numerical studies on an S809 airfoil and the airfoil at the cross section with 30%relative thickness of the blade on a 1.5 MW wind turbine.The flow control effect of VGs was carried out and analyzed.The results indicate that VGs can delay the stall angle of attack(AOA)and improve the maximum lift coefficient for the S809 airfoil.At low AOAs,the VGs slightly increase the airfoil drag because of its own shape.Due to the separation delay,VGs reduce the airfoil drag with an increase in AOA.When AOA excess 17.21°,the separation point will move forward to the front 20%c of the airfoil where VGs have no effect of drag reduction.The blunt trailing edge and large thickness of the airfoil of the 1.5 MW wind turbine provide good stall and a more prominent effect of lift enhancement and drag reduction.This research is a valuable reference for the VGs flow control of wind turbine blades.