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气动热环境下高速飞行器的光学头罩由于受气动热效应作用,其温度急剧升高,产生严重的气动热辐射效应。为评估气动热环境下高速飞行器光学头罩热辐射对探测系统性能的影响,采用有限光线代表连续辐射的方法,并引入热瞳概念建立了气动光学头罩热辐射传输计算模型并对气动光学头罩自身干扰辐射光线在光学系统内的传输进行了数值仿真,考察了光学头罩温度场为非均匀分布时其自身干扰辐射在探测器接收面的辐照度分布。研究结果表明:由头罩顶点求得的热瞳是光学头罩热辐射能的公共入口,它可将光线追迹的时间减小至追迹全部光线所需时间的十几分之一;根据探测器接受面干扰辐射随时间的变化趋势可知在飞行数秒后头罩干扰辐射将淹没目标信号,气动光学头罩热辐射效应不容忽视。
Aerodynamic thermal environment of high-speed aircraft optical hood as a result of the role of aerodynamic heat, the temperature rose sharply, resulting in severe aerodynamic heat radiation effect. In order to evaluate the influence of thermal radiation of high-speed aircraft optical hood on the performance of the detection system under aerodynamic thermal environment, a finite-ray method is used to represent the continuous radiation. The concept of thermal pupil is introduced to establish the thermal radiation transfer calculation model of aero-optical hood. The radiation of the cover itself interfered with the transmission of the radiation in the optical system was numerically simulated. The distribution of irradiance of the self-interfering radiation on the receiving surface of the detector when the temperature field of the optical hood was non-uniform was investigated. The results show that the thermal pupil obtained from the tip of the hood is the common entrance of thermal radiation of the optical hood, which can reduce the time of ray tracing to one-tenth of the time required for tracing all the light. According to the detection The change tendency of the interference radiation of the receiving surface with time shows that the interference radiation of the hood will submerge the target signal after a few seconds of flight and the thermal radiation effect of the aerodynamic optical hood can not be ignored.