高速流场对光传输特性的影响

利用一座小型跨超声速风洞进行了高速流场光传输特性试验研究。光束在高速流场中传输时,由于流场密度变化,光波波前会发生畸变。利用风洞提供0.7,2.0和3.0等气流马赫数的流场条件,采用基于夏克-哈特曼波前传感器的光学测量系统,对光束在风洞流场中传输时的波前畸变进行了测量。试验结果表明:随着风洞流场马赫数增加,流场对光波传播的影响增大,光波波前畸变量显著提高。因此,在利用风洞进行气动光学试验研究之前,有必要消除风洞流场本身对光波传输的严重干扰。

High-speed flow impacts on transmission features of light beam

Experiments are conducted in a small transonic wind tunnel to investigate the impacts of the high-speed flow on the transmission features of light beam. Aberrated wavefronts of light beam travelling through the flow field in the wind tunnel test section with nominal Mach numbers 0.7, 2.0, 3.0 are measured by a Shack-Hartmann wavefront sensor based optical system. Some interesting results including the peak variation (PV), the root of mean square (RMS) and the far-field focal spot are obtained, which suggest that the influence of high-speed flow field increases with the increased flow speed, and the related aberration of wavefront grows rapidly especially when the Mach number is greater than 3.0. Thus it is essential to eliminate the severe disturbance of the flow field in the test section