临近空间超声速航空遥感器光学窗口热光学评价

为提高航空遥感器光学窗口的光学性能,对处于临近空间超声速飞行状态下熔石英材料的光学窗口进行了热光学评价。分析了光学窗口所处的飞行环境,根据空气动力学原理,计算了平均对流换热系数与马赫数的关系。根据热流密度,模拟了光学窗口温度场分布;计算了内外表面温差所引起的光程差;并分析了光学窗口热变形对航空遥感器光学系统传递函数的影响。分析结果表明:由热变形带来的光学窗口光程差PV=130.5 nm,满足光学设计要求(PV1/4)。此研究结果可为光学窗口系统设计提供必要依据。

Thermal-optical evaluation to optical window of near space aerial remote sensor surrounding hypersonic

In order to improve the optical performance of optical window in aerial remote sensor, thermal-optical evaluation to fused silica optical window surrounding hypersonic was analyzed. The flight environment of optical window was analyzed. Based on the theory of aerodynamics, the relation between convection heat transfer coefficient and mach number was calculated. The temperature distributing of optical window was simulated by heat flux density, the optical path difference caused by the temperature difference between the inner and outer surfaces was calculated, and the influence of thermal deformation of the optical window on optical transfer function was analyzed. The study result shows that the optical path difference caused by thermal deformation of the optical window is 130.5 nm, which is under 1/4. The simulation result meets the requirements of the optical design. The above result discussed in this paper can be used as a reference for other optical window designs.