高超声速条件下星光传输模拟方法与仿真

以高超声速飞行器为研究对象，建立了高速流场下的星光传输模拟仿真方法，定性、定量地研究平台气动光学效应对星光导航的影响。采用基于k-ω/SST两方程湍流模型的雷诺平均法计算星敏感器安装在飞行器不同位置处（头部、中部和尾部）的外流场密度分布，进而得到流场的空间折射率分布。在此基础上，利用几何光学法计算星光由高速层流流场引起的光程差、点扩散函数、像偏移等光学传输效应，得出经过层流流场的星光降晰图。同时运用统计光学理论计算高速湍流流场引起的星光出瞳面的波像差、密度均方差、相位均方差、Strehl比等光学传输效应，得出经过湍流流场的星光降晰图。仿真结果与理论分析吻合，从而为研究星光在高超声速流场中传输的机理提供了可靠的技术手段。

Simulation on Starlight Transmission under Hypersonic Flow Field

A simulation method for starlight transmission is established to qualitatively and quantitatively research aero-optical effects of the platformon starlight navigationby taking a hypersonic vehicle as the research object. Firstly, Based on Reynolds average, the k-ω/SST two-equation turbulent model is used to calculate the density distribution of external flow field when the star sensor is installed at different locations in the vehicle (head, middle and tail), and then the spatial refractive index distribution of the flow field can be gotten. On this basis, the geometrical optics method is used to such optical transmission effectsas calculate the optical path difference, the point spread function, the image offset andso on, caused by the laminar flow field, and then obtain the laminar flow diagram with lower clarity. At the meantime, the statistical optics method is used to calculate wavefront distortion, mean square deviationsof density and phase, Strehl ratioand other optical effects to get the diagram with lower claritythrough the turbulent flow field. The simulation results fit in with the theoretic analysis, and the method is more useful and reliable in researching the mechanism of starlight transmission in the hypersonic flow field.