Research on the Infrared Radiation Suppression of the High-Temperature Components of the Helicopter with an Integrated Infrared Suppressor

Abstract

The integrated infrared suppressor can reduce the infrared radiation signal of a helicopter and is compatible with radar-acoustic stealth. However, the issues that are caused by the integrated infrared suppressor, such as temperature increases on the rear fuselage surface and a lack of shielding at the exhaust port, need to be addressed, in order to further improve the infrared stealth capability of the helicopter. Aiming at this, the effects of the ambient temperature, fuselage surface emissivity, mixing duct shielding, and exhaust port shielding on the infrared radiation characteristics of the helicopter are studied with numerical simulation. The results show that the infrared radiation intensity of the helicopter, in 3–5 μm band and 8–14 μm band, decreases by about 20% and 10%, respectively, for every 6 K reduction in the ambient temperature. As the emissivity of the rear fuselage surface reduces from 0.8 to 0.5, the helicopter’s infrared radiation intensity, in a 3–5 μm band and a 8–14 μm band, decreases by about 6% and by about 4% and 1.3%, respectively, after the mixing duct is equipped with a shielding sheath. Installing deflectors at the exhaust port of the fuselage can prevent the detection rays from detecting the high-temperature components inside the fuselage, and when the emissivity of the deflectors is reduced from 0.8 to less than 0.5, or the deflectors are cooled by more than 80 K, they begin to play a role in suppressing the infrared radiation at the bottom of the helicopter.