气动光学窗口热辐射效应建模研究

Modeling of Thermal Radiation Effect of Aero Optical Window

飞行器在大气层内高速飞行时产生严重的气动光学效应,光学窗口因气动加热,温度急剧升高,产生强烈的红外辐射,形成辐射干扰,导致红外探测器产生非均匀辐射背景,严重影响成像质量,降低接收系统的信噪比和探测距离。主要研究窗口热辐射效应,使用有限元分析法,将光学窗口划分成规则网格,计算每个网格的辐射能,运用光线追迹法,得到像面上的辐射分布及像元上的辐通量。最后利用所建立的模型对均匀温度和存在温度梯度的窗口进行了仿真。

When a vehicle files in atmosphere at a high speed, it can generate serious aero optical effect. The temperature of optical window rises sharply because of aerodynamic heating. It will create strong infrared flux and form radiation interference that can cause the infrared detector to generate non-u- niform radiation background, which seriously affects the image quality, and degrading SNR of the receiv- ing system and detection range. The thermal radiation effect of aero optical window is studied by finite el- ement analysis method. The optical window is divided into uniform grids, and the radiant energy of each grid is calculated. Then, the radiation distribution on the focal plane and radiant flux on each pixel are obtained with ray tracing method. Finally, the windows with uniform temperature and vertical temperature gradient are simulated by the model built.