当带有光学成像探测制导系统的高速飞行器在大气层内飞行时，光学窗口与来流之间会形成复杂的凹腔绕流流场，产生气动光学效应。建立了求解超声速流场的高精度LES/RANS混合算法模型，研究了超声速流动条件下的Settles三维凹腔流动；在计算得到精确流场数据的基础上，研究了凹腔剪切层区域的光学传输效应。结果表明，凹腔流动的剪切层结构将引起光线抖动，导致严重的波面畸变，明显降低光强斯特雷尔(Strehl)比，严重影响光学传输性能，进而大大降低光学制导精度。

When the vehicle with optical seeker in its head side window flights at high speed in aerosphere, cavity flow phenomena occurs. So, the high-precision LER/RANS hybrid algorithm model is established to solve supersonic flow. The Settles three dimensional carity′s supersonic flow is studied. And then, on the basis of accurate numerically calculated flow-field data, the optical transmission effect of the cavity shear layer region is researched. The results show that, the shear layer structure of cavity flow will cause light jitter, lead to severe wave-front distortion, reduce light intensity Strehl ratio significantly, and reduce the accuracy of the optical guidance.