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 FORTRANprograms 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.