소형 제트엔진 배기플룸의 열유동장 및 화학성분의IR 신호 영향성 전산해석

Abstract

Because of high levels of infrared signature generated by engine exhaust plume, aircraft can be detected by infrared guided missiles equipped with a modern detector. In order to investigate the characteristics of plume IR and reduce the level of its signature, the exhaust plume around an engine nozzle was calculated with a Navier-Stokes-Fourier computational code. The narrow-band model was employed to calculate the spectral characteristics of the IR signature. Computational models were compared with the experimental results of a micro jet engine. By considering an aircraft flying at an altitude of 20,000 ft, the effects of thermal flow field and chemical components on the IR signature was investigated. As expected, the plume IR signature showed the greatest effect at 4~4.5 μm CO2 and 5~8 μm H2O, and the temperature affected the IR signature over the whole band. In addition, the molar fraction change in CO2 and H2O resulted in higher variation in plume IR signature.