Numerical investigation of aircraft infrared characteristics in 8-14 μm band

Practical ways of modeling aerodynamic heating under supersonic flight conditions, flow and heat transfer inside aero-engine nacelle, and plume heating on the rear fuselage of aircraft were introduced for simulating the aircraft skin temperature distributions. Infrared radiation characteristics in 8-14 m band of skin and engine wall was studied by numerical calculation method. Contribution of head, fuselage (including inlet entrance), wing, engine compartment (including rear fuselage), vertical stabilizer, horizontal stabilizer and engine nozzle cavity to infrared radiation were analyzed. The results show that skin infrared radiation is the major component of the infrared radiation in 8-14 m band and the infrared radiation of the engine wall is mainly focused on the aircraft tail in the visual range of 50. The individual infrared radiation of skin compartment takes different proportion of total infrared radiation in different observation plane. The main sources of infrared radiation are aircraft body, wing, aero- engine nacelle and upward vertical tail. Aerodynamic heating effect is exacerbated with the rising of flight Mach number, as a result of which proportion of each part of the aircraft infrared radiation changed.