飞行器后机身蒙皮红外辐射特性(英文)

IR characteristics of aircraft aft fuselage skin

随着红外探测和红外制导技术的迅猛发展,飞行器的生存力受到越来越大的威胁,如何降低飞行器的红外辐射特征成为提高隐身能力的关键技术之一,排气系统是飞行器后半球的主要红外辐射源。为了研究飞行器后机身蒙皮的红外辐射特性,针对飞行器的后机身蒙皮,结合涡扇发动机引射喷管的CFD计算,采用离散传递法计算了典型作战飞行器在8～14μm波段的红外辐射强度分布。在红外计算过程中,考虑了发动机固体壁面的发射和反射,飞机蒙皮的发射,燃气内CO2、H2O和CO的吸收与发射作用;并通过冷却、隔热等措施降低后机身发动机热影响区蒙皮的温度对红外辐射特征的影响进行了研究。计算结果表明:后机身发动机热影响区温度降低70 K,在红外探测的主要威胁方位头向5°范围内可以降低整机红外辐射强度9.1%,30°可以降低15.4%,60°可以降低17.5%,在正下方90°,可以降低18.9%;在此基础上采用低反射率可以在各个方向上进一步降低飞机的红外辐射强度,除了正后向及附近排气系统喷管腔体影响强烈扇区间以外,都能降低到20%以内。计算结果和方法为飞行器红外隐身设计提供了有益参考。

The rapid development of infrared detection and infrared guidance technology poses more threat to the survival ability of aircraft. How to reduce the infrared radiation of the aircraft becomes one of the key technologies to improve the ability of stealth. The exhaust system of aircraft is the main source of infrared radiation. In order to study the IR characteristics of the aft fuselage skin, based on the discrete transfer method in the paper, the infrared simulation of the aft fuselage skin for a typical fight aircraft was carried out to analyze the infrared radiation intensity distribution of the aft fuselage skin for a typical combat aircraft with the ejector nozzle in 8-14 μm band by the form of a combination of the computational fluid dynamics （CFD） commercial software and self-developed IR computing software. In the IR calculations, the emission and reflection of the solid wall of the engine, aircraft skin launch, gas, CO2, H2O and CO absorption and emission effects were taken into account. Finally, the IR intensity of the fighter were investigated using the cooling insulation way and low infrared emissive material. It was found that the temperature of the engine heat-affected zone of the aft fuselage of the fighter were reduced by 70 K, the IR intensity of aircraft declined by 9.1%, 15.4% and 17.5% in the infrared detecting main threat orientation of the head within 5°, 30° and 60°, and reduced by 18.9% in just below 90°. The skin of the engine heat-affected zone were covered by low emissive material, the IR could be reduced by 20% in the font basis. The results of research in this paper are of considerable guiding significance and referential importance for designing infrared stealthy aircraft.