基于涡流发生器的风洞试验段附面层控制数值模拟

沿试验段侧壁发展的附面层是影响飞行器半模型实验数据精准度的主要因素之一.利用数值模拟方法验证了涡流发生器减小附面层影响的可行性，重点分析了安装角度、结构尺寸、安装位置及个数等设计参数对附面层内速度分布的影响规律，对涡流发生器尾涡强度以及沿流向的发展规律进行了初步探讨.结果表明，涡流发生器产生的尾涡能够有效改善附面层内的速度分布，进而减小附面层厚度，降低附面层影响；涡流发生器的后缘应略高于当地附面层厚度，安装角度、位置、个数等参数必须合理设计以减小涡流发生器对试验段主气流的影响.基于计算结果初步设计了可用于2.4 m跨声速风洞半模试验段的涡流发生器，在亚声速范围内能够减小模型区侧壁附面层厚度66%左右，对核心流Mach数影响小于0.003，为涡流发生器的实际应用提供了依据. 

Numerical Investigation on Boundary Layer Flow Control in Wind Tunnel Test Section with Vortex Generators

The boundary layer developed along the side wall of the test section is one of the main factors affecting the accuracy of the aircraft semi-span model test data. The numerical simulation method was used to verify the effect of vortex generator on reducing the boundary layer influence. The influence of design parameters such as installation angle, structure size, installation position and number on the velocity distribution inside boundary layer was analyzed in detail. The strength of wake vortices and development along the flow direction were discussed. The results show that the wake vortices generated by the vortex generators are capable of improving the velocity distribution inside boundary layer, therefore decreasing the boundary layer thickness and reducing the influence of the boundary layer. The trailing edge of the vortex generator should be slightly higher than the thickness of local boundary layer. The installation angle, position, number must be reasonably designed to reduce the influence of the vortex generators on the main flow of the test section. Based on the results, vortex generators that can be used in the half-model test section of 2.4 m transonic wind tunnel is preliminarily designed, which are capable of reducing boundary layer thickness for about 66 percent in model area, and the influence on centerline Mach number is less than 0.003. Research results can be used for further vortex generators applications in wind tunnel tests.