高超声速拦截弹绕流红外辐射特性数值模拟

研究拦截弹绕流红外辐射特性对红外导引头设计具有重要意义。基于求解化学非平衡Navier-Stokes方程的方法，对高超声速拦截弹化学反应绕流进行数值模拟。在此基础上，基于谱带辐射模型，对拦截弹侧面的光学窗口附近流场在0.8~20 m波段的光谱辐射特性进行数值计算，分析窗口附近流场红外光谱辐射随飞行参数的变化特征和规律。研究表明:拦截弹窗口流场光谱辐射主要来源于CO2和NO分子的振动-转动谱带；飞行马赫数一定，窗口流场光谱辐射沿飞行高度的变化规律主要由流场中气体分子的数密度分布主导；飞行高度一定，窗口流场光谱辐射随飞行马赫数的变化规律主要由流场温度控制，随着飞行马赫数增大，流场中NO分子的光谱辐射效应增强。

Numerical simulation of infrared radiation characteristics of flow over hypersonic interceptors

It is of great importance to study the infrared radiation characteristics of flow over hypersonic interceptors for the design of infrared seeker. The flow field over a hypersonic interceptor was simulated numerically by solving Navier-Stokes equations with chemical non-equilibrium terms. Based on the flow field, the infrared radiation from the flow over the optical window on the side of interceptor in 0.8-20 m range was computed using a spectral band model, and the change rules of the flow radiation versus flight parameters were researched. The research shows that the spectral radiation of the flow mainly comes from the vibration-rotation bands of CO2 and NO molecules, the change rules of spectral radiation versus flight altitude are dominated by the number densities distribution of molecules species in the flow with a constant flight Mach number, and the change rules of spectral radiation versus flight Mach number are controlled by flow temperature with a constant flight altitude, and the spectral radiation of NO molecule in the flow strengthens with increasing flight Mach number.