近空间高超飞行器气动热红外特性数值仿真

Numerical Simulation of Aero-thermal Infrared Radiation of Near Space Hypersonic Vehicle

研究飞行器提高自身生存和突防能力,提高红外探测精度,针对近空间高超声速飞行器的气动热红外辐射特性开展了数值仿真研究。利用Jameson中心差分格式,并引入了类TVD变量修正,数值求解三维Navier-Stokes方程获得较为精确的流场参量。以已知流场参量为基础,采用精细的逐线计算模型计算气体的辐射吸收系数,考虑了光谱线的压力增宽和多普勒增宽混合效应;通过有限体积法求解辐射传输方程,空间离散采用与流场相同的计算网格,避免了插值的麻烦,采用了一种较为精确的离散格式。以典型的锥导乘波构型为例,应用所建方法和计算程序数值仿真了其在3~5μm波段的红外辐射空间分布。仿真结果分析表明,模型和方法是合理可行的,可以为红外隐身设计提供一定的参考依据。

With the design of infrared stealth as application background,this paper has done research on numerical simulation of aero-thermal infrared radiation of near space hypersonic vehicle.For obtaining more accurate flow field parameters,the Jameson central difference scheme with TVD amendment is used to solve Navier-Stokes equations.On the basis of known flow field parameters,a precise Line-by-Line method is employed to calculate radiation absorption coefficient of gases,considering mixed effect of pressure broadening and Doppler broadening of spectral lines.The finite volume method is applied to solve radiation transfer equation,adopting the same grid as flow field for space discretization which eliminates the trouble of interpolation and a new more accurate scheme for angular discretization.Finally,the method and computational codes established in this paper are applied to numerically simulate the infrared radiation spatial distribution within 3~5μm of a typical cone-derived wave-rider configuration.The analysis of simulation result demonstrates that the established model and method are reasonable and feasible,and the simulation result obtained can provide a reference to some extent for the design of infrared stealth.