柔性后缘可变形机翼气动特性分析

应用后缘主动变弯度技术的机翼能够改善飞行器的气动性能,其气动特性的研究对于未来可变形机翼的设计具有重要意义。以柔性后缘可连续变弯度二元机翼为研究对象,在Fluent计算平台上采用可压缩Navier-Stokes方程和Spalart-Allmaras(S-A)湍流模型进行气动力数值研究,从压力分布、流场结构和机翼变形方式等方面分析了可变形机翼的气动特性。数值计算结果表明,可变形机翼升力线斜率和最大升力系数与常规带简单襟翼的机翼基本一致,但失速攻角较小;在失速之前,可变形机翼具有较高的升力系数和升阻比,但同时产生较大的低头力矩。柔性后缘下偏到一定角度可以抑制后缘涡的前传,在失速后升力系数出现缓慢上升,增大了有效攻角的范围,具有较好的失速特性。 

Analysis on aerodynamic characteristics of morphing wing with flexible trailing edge

The wing applying active variable camber trailing edge technology can improve aircraft's aerodynamic performance, and the study of aerodynamic characteristics is of great significance to the design of the morphing wing. Choosing the 2D variable camber wing with flexible trailing edge as the object of study, the compressible Navier-Stokes equation and Spalart-Allmaras (S-A) turbulence model were applied to investigate the aerodynamics of morphing wing numerically by using the software Fluent. Aerodynamic characteristics were studied from the perspective of pressure distribution, flow field structure and the deformation mode. The numerical results show that the morphing wing has almost the same slope of lift curve and maximum lift coefficient with the conventional wing with simple flap, but has lower stall angle of attack. It has higher lift coefficient, lift-to-drag ratio, and higher nose-down pitching moment coefficient than conventional wing before the occurrence of stall. When flexible trailing edge deflects downward to a special angle, trailing edge vortex is suppressed to expand forward. The lift coefficient slowly rises after the stall, which increases the range of effective angle of attack of morphing wing and leads to a good stall characteristic.