Since the shape and optical properties of a aero-optical dome change as the dome is subjected to aerodynamic heating, the optical transmission of the dome is affected. A finite element analysis model of the dome was established to numerically compute its refractive index distribution based on the theories of thermo-optical and elastic-optical effects. The optical transmission of infrared radiation through the dome was numerically simulated using the ray tracing program based on the fourth order Runge-Kutta algorithm. Two kinds of imaging quality evaluation parameters were presented, wave aberration of the exit pupil and MTF. The research results show that the thermo-optical effect has a much greater influence on optical transmission through the dome compared with the elasto-optical effect and the imaging quality of the dome is seriously affected due to aerodynamic heating. Therefore, the effect exerted by aerodynamic heating on the optical transmission of the dome can not be neglected for improving the guidance precision of missies .%气动热环境下光学头罩由于受气动热效应作用,其形状和光学性质都将发生改变,从而影响头罩内的光传输.建立气动光学头罩有限元分析模型,根据热光效应和弹光效应理论,对头罩的折射率场进行数值计算,采用四阶龙格-库塔法编制光线追迹程序对气动光学头罩内红外辐射光线传输进行了数值仿真,得到了头罩光学系统出射波面波像差和调制传递函数.研究结果表明:气动热环境下热光效应对光学头罩光传输的影响远比弹光效应大,且气动光学头罩成像质量受到气动热效应的影响严重下降,为了提高高速飞行器的制导精度,不能忽视气动热对头罩光传输的影响.
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