分析了蒙皮、发动机排气系统等主要辐射源的红外辐射特性, 结合红外辐射理论、实测数据以及经验公式, 建立了某型直升机红外辐射强度简化算法, 分析了不同观测角度下机体不同部位对红外辐射的贡献值, 得到了3~5 μm、8~14 μm波段红外辐射强度全向分布曲线, 验证了计算模型的可行性。结果表明, 直升机红外辐射具有很强的方向性, 其辐射强度与观测角度有很大关系, 迎头方向辐射最小, 机体侧后方的辐射最强, 且长波辐射强度要强于中波辐射；长波辐射主要来自于蒙皮自身辐射, 不低于总体辐射的70%；中波波段辐射主要来自于发动机排气管部分, 且在机体侧后方辐射最大。最后, 利用计算结果仿真分析了不同角度袭来的目标对探测距离的影响。对于迎头袭来的目标的探测距离最小, 对于机体侧后方约110°方位的探测距离最大。研究对直升机红外辐射探测系统探测距离评估具有重要的意义。

The two parts of helicopter IR radiation were researched, including the engine exhaust system radiation and skin radiation. Based on the IR radiation theory, measured data and empirical formula, the theoretical calculation methods were proposed. The IR radiation of the two parts in different detection angles were analyzed, and the IR radiation intensity distribution of 3~5 μm and 8~14 μm in different detection angles were set up. The results show that the method is feasible, and helicopter IR radiation intensity is variable in different detection angles. The IR intensity is weaker by viewing from the front, and strong by viewing from the lateral and back. The 8~14 μm radiation is more than 3~5 μm radiation, which is 70% mostly from skin radiation. The 3~5 μm radiation is mostly from the engine exhaust system radiation, and becomes the major source of IR in lateral and back view. The simulation of detection range in different angle indicates that the detection range is affected with target detection angle, which is the least from front view and the most from angle of 110°. This infrared radiation theoretical calculation of helicopter is important for detection range evaluation of IR system.