Abstract:This paper aims at the problem of aero-optical effects in the mixing layer flow field with different velocity ratios. Firstly the large eddy simulation method is used for numerical simulation. Secondly the ray tracing method is used to simulate the aero-optical effects. Finally an aero-optical evaluation of the mixing layer is carried out. The results show that there is a remarkable correspondence between the vortex structure of the mixing layer flow field and the minimum optical path difference. The aero-optic effects of mixing layer with low velocity ratio is more serious than the others flow fields. Meanwhile, the effects of different optical parameters on Strehl ratio are studied and the corresponding laws are obtained.