带超声速气膜高超声速光学头罩气动光学效应抑制实验

高超声速（Ma_∞=6.0）炮风洞中带超声速（Ma_c=3.0）喷流光学头罩受到周围绕流影响出现气动光学畸变.利用基于背景纹影（background oriented schlieren，BOS）的波前测试方法测量了光学波前畸变.研究结果表明:瞄视误差（bore sight error，BSE）与喷流压比（pressure ratio of jet，PRJ）之间近似呈正相关.在有喷流的情况下，压力匹配时瞄视误差相对比较小，并且喷流压比对气动光学高阶畸变的影响不显著.微型涡流发生器（micro vortex gene-rator，MVG）对瞄视误差影响不明显，但是对气动光学高阶畸变的影响较为显著.基于波前互相关结果，施加微型涡流发生器之后，波前结构尺寸从0.2A_D减小为0.1A_D.结构尺寸的减小较为有效地抑制了气动光学高阶畸变并且提高了波前的稳定性. 

Experimental Investigation on Aero-optics Imitation of Hypersonic Optical Dome with Supersonic Film

The aero-optical distortion was caused by the flow field around an optical dome with supersonic (Ma_c=3.0) gas injection in a hypersonic (Ma_∞=6.0) gun wind tunnel. A wavefront measurement method based on background oriented schlieren (BOS) was adopted to obtain the distorted optical wavefront. There is a positive correlation between bore sight error (BSE) and the pressure ratio of jet (PRJ). Under jet condition, BSE is relatively small when PRJ=1, and PRJ has no significant effect on the higher-order aero-optical distortion. The effect of micro vortex generator (MVG) on BSE is not obvious, although the effect of MVG on the high-order aero-optical distortion is obvious. Based on the correlation result of wavefront, after the application of MVG, the structure size of wavefront is reduced from 0.2A_D to 0.1A_D. The decrease of structure size effectively inhibits the high-order aero-optical distortion and improves the stability of wavefront.