低雷诺数下柔性翼型气动性能分析

基于流固耦合方法对吸力面5%至95%弦长处为三段柔性结构的NACA0012翼型绕流进行了数值模拟,研究了不同弹性模量下柔性翼型的气动性能和结构响应.结果表明:在大攻角下,翼面变形影响着翼型表面的非定常流场,起到延缓失速和提高升力的作用;失速后柔性翼的升力系数下降得较为缓慢,且柔性越大,升力系数下降得越平缓;适当减小弹性模量能够提高翼型的气动性能,然而弹性模量过小反而不利于翼型气动性能的提升,并且翼面会产生大幅度的振动.

THE AERODYNAMIC PERFORMANCE OF A FLEXIBLE AIRFOIL AT LOW REYNOLDS NUMBER

A two way fluid-structure interaction method is employed to simulate the aerodynamic performance and the structural response of NACA0012 airfoils,with three flexible structures on a portion of the upper surface extending from 5％ to 95％ of the chord from the leading edge.The impact of the elastic modulus is analyzed.It is indicated that at a large angle of attack the deformation of the flexible surface affects the unsteady flow field around the airfoil,delays the stall and improves the lift coefficient.Even when the stall occurs,the lift coefficient of the flexible airfoil decreases more slowly with the increase of the angle of attack than that of a rigid airfoil.The flexible airfoil with smaller elastic modulus has better aerodynamic performance.But too small elastic modulus is not conducive to the enhancement of the aerodynamic performance and the flexible surfaces will experience a large amplitude vibration.