表面浅凹槽对NACA翼型叶片气动特性影响的研究

Research on the influence of surface shallow grooves on aerodynamic characteristics of NACA airfoil blades

在小型风力机叶片表面设置浅凹槽可以实现对叶片周围流场的被动控制,以改善叶片的气动性能。文章对表面不同位置设置浅凹槽的NACA叶片在均匀流场中的表现进行了数值模拟,考察了前凹槽位置对叶片升阻比的影响。研究表明:随着攻角增大,在叶片上表面靠近尾部位置的流体发生分离;在叶片前缘下表面设置凹槽可以减小尾部流体分离的区域,使得后缘的分离泡明显消失,然而,叶片前缘附近的速度梯度增大;当攻角α=2°时带凹槽叶片的最大升阻比达到最大值,为109.5,比未设置凹槽叶片提升了13.8%;研究结果可为小型风力机NACA叶片设计提供有价值的参考。

Setting shallow grooves on the surface of small wind turbine blades can passively control the flow field around the blades to improve the aerodynamic performance of the blades.This paper conducts a numerical simulation on the performance of NACA blades with shallow grooves at different positions on the surface in a uniform flow field,and examines the effect of the front groove position on the lift-to-drag ratio of the blade.Research shows that as the angle of attack increases,the fluid on the upper surface of the blade near the tail is separated;setting a groove on the lower surface of the blade leading edge can reduce the area of fluid separation at the tail,making the separation bubble on the trailing edge disappear significantly.However,the velocity gradient near the blade leading edge increases;when the angle of attackα=2°,the maximum lift-drag ratio of the grooved blade reaches the maximum value as 109.5,which is 13.8%higher than that of the blade without grooves;the conclusion of this article can provide valuable reference for small wind turbine NACA blade design.