红外窗口气动热辐射效应评估方法  

Evaluation method for aero-thermo-radiation effect of IR window

作　　者：王亚辉[1,2,3] 王强[1] 张伯川[2,3] 郑文娟[2,3] 刘彦[2,3] 徐力[2,3] 

机构地区：[1]北京航空航天大学能源与动力工程学院,北京100191 [2]北京航天自动控制研究所,北京100854 [3]宇航智能控制技术国家级重点实验室,北京100854

出　　处：《红外与激光工程》2016年第2期53-58,共6页Infrared and Laser Engineering

基　　金："十二五"预研项目(51301030101)

摘　　要：气动热辐射效应导致红外探测制导系统的性能降低甚至失效，而红外窗口是气动热辐射效应评估的关键因素。通过分析红外辐射在红外窗口中的传输特性，提出一种红外窗口气动热辐射效应评估方法，基于等温状态试验，评估了某超音速飞行器红外探测系统蓝宝石红外窗口在中波3．7～4．8μm波段的气动热辐射效应。研究结果显示，红外窗口暴露于大气环境后，蓝宝石窗口导致的气动热辐射效应迅速上升，表现为红外窗口透过率下降约10％，仍然在0．9以上，而自辐射迅速增强约458倍，相当于约125℃黑体，在探测器获取总辐射中的比例大于78％。在对地探测应用中，对于厚度小于20min的蓝宝石红外窗口，窗口温度在100～350℃范围内，随着厚度增加，透过率下降，自辐射增强，总辐射也增强，自辐射在总辐射中的比例增加，易造成探测器饱和，对探测系统影响较大。The windows of IR detection systems becomes the main factor of the aero-thermo-radiation effect, which reduces the performance of these IR systems, or even makes these systems fail. By analyzing thermal radiation propagating in IR windows, a participating medium, an evaluation method for aero-thermo-radiation effect of the non-isothermal IR windows was proposed, based on the experimental results of the isothermal state, include self-radiation and transmittance. Aim to an MWIR detection system of a hypersonic vehicle, aero-thermo-radiation effect of a sapphire IR window was evaluated in 3.7-4.8 μm. The results indicate that, as the sapphire IR window is exposed in high-temperature and high-speed airflow, the aero-thermo-radiation effect of the window intensifies as temperature rises rapidly, the transmittance drops about 10%, still bigger than 0.9, otherwise the self-radiation enhances 458 times approximately, equal to that of blackbody about 125 ℃. For sapphire windows in 100-350 ℃, which thickness are smaller than 20 mm, as thickness increases, the transmittance decreases, self-radiation increases, and total radiation behind sapphire windows is increased, of which the ratio of self-radiation increases. So, self-radiation would drive detector into saturation easily, of which the influence on the MWlR detection system is bigger than that of transmittance.

关 键 词：气动热辐射效应 红外窗口 自辐射 透过率 

分 类 号：TK124[动力工程及工程热物理—工程热物理]