发动机排气系统及尾喷流的流场和红外特征数值模拟

Numerical simulation of flowfield and infrared characteristics of an aeroengine exhaust system and its plume

建立了发动机排气系统及尾喷流的内外流一体化流场数值模拟计算模型，得到了发动机排气系统及尾喷流的流场．然后采用辐射传递方程（RTE）积分法研究了发动机排气系统及尾喷流的红外辐射特征，开发了相应的红外辐射特征计算源程序．程序可以计算加力和非加力两种状态下的红外光谱辐射特征，在加力状态下主要增加考虑了soot粒子的光谱吸收与发射．气体介质考虑了水蒸气、二氧化碳、一氧化碳和一氧化氮的红外光谱吸收与发射．最后给出了在光谱3～5μm范围内，某发动机在高空飞行时其排气系统及尾喷流在加力和非加力状态下的红外辐射特征的模拟结果．

The flow field of an aeroengine exhaust system including its inner space and outer space was calculated using the Navier-Stokes equations. And then the infrared calculation model of the aeroengine exhaust system and its plume using integration method of the radiative transfer equation （RTE） were established. The corresponding FORTRAN programs for the infrared radiation calculation were written, which can simulate two cases if the after burner is on or not. If the after burner is on the soot absorption and its radiation must be considered except for the gas media radiation of the water stream, the carbon dioxide, the carbon monoxide and the nitrogen monoxide. This paper finally gives the simulated results of the infrared characteristics in the wave of 3-5 μm in the flying condition of high altitude.