Calculation of infrared radiation characteristics of aircraft environmental control system exhaust

This paper proposed an engineering calculation method for infrared radiation characteristics of aircraft environmental control system exhaust. The study was based on computational fluid dynamics (CFD) and the fundamental theory of radiative transfer. First, the temperature filed of the environmental control system exhaust was simulated by CFD model. The obtained temperature filed was then divided into a quantity of layers with the same temperature and pressure from inside to outside. Subsequently, the infrared intensity of the carbon dioxide and vapor in the exhaust of each layers was calculated respectively From accumulating the calculated infrared intensity of each layer, the total infrared intensity of the environmental control system exhaust was obtained in presence of the radiant energy attenuation. Finally, the infrared intensity in 3∼5 μm and 8-14 μm bands along with the detection angles was depicted and analyzed.