前缘脱层对风力机翼型流场和气动性能的影响

为研究前缘磨损对翼型气动性能的影响,以风力机专用翼型S809为研究对象,采用SST k-ω湍流模型进行数值计算,研究不同前缘脱层深度对翼型流场和气动性能的影响.结果表明:前缘脱层改变了翼型形状,使得前缘流动变为台阶流动,造成后缘分离区变大、分离点前移.随着脱层深度和攻角的增大,吸力面前缘回流漩涡和后缘分离区由相互独立状态变为完全融合.同一攻角下,前缘脱层对前缘的压力系数影响较大.攻角小于3°时,前缘脱层对翼型的升、阻力系数影响较小,攻角大于3°后,随着脱层程度的加深,翼型的升力系数逐渐减小,阻力系数逐渐增大.相对于光滑翼型前缘脱层翼型升力损失率最高达55.08%,阻力增长率最大达150.48%.

Influence of leading edge delamination on flow field around airfoil and aerodynamic performance of wind turbine

In order to study the effect of leading edge wear on the aerodynamic performance of airfoil, a special-purpose airfoil S809 for wind turbines was taken as investigation object, and SST k-ω turbulence mode was used to carry out its numerical computation, and study the effect of different leading edge delamination depths on the flow field around airfoil and aerodynamic performance. The results show that the leading edge delamination will change the shape of the airfoil, so that the leading edge flow will become a step flow, causing the flow separation zone at trailing edge to expand and the separation point to move forward. With the increasing of the delamination depth and the angle of attack, the flow separation zone at trailing edge of airfoil on suction surface and the backflow vortex at leading edge of airfoil on suction surface will be changed from mutually independent state of each other to completely fused. Under condition of identical angle of attack, the leading edge delamination will have a greater influence on the pressure coefficient on the blade surface at the leading edge. When the angle of attack is less than 3°, the leading edge delamination will have little effect on the lift and drag coefficient of the airfoil. When the angle of attack is greater than 3°, the lift coefficient of the airfoil will gradually decrease as the degree of delamination becomes higher, but the drag coefficient will gradually increase. Compared to a smooth airfoil, the lift loss rate of airfoil with leading edge delamination will amount to its maximum of 55.08% and the drag growth rate 150.48%.