Effects of exhaust temperature on helicopter infrared signature
Effects of exhaust temperature on helicopter infrared signature
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DOI：
10.1016/j.applthermaleng.2012.09.016
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发表时间：
2013-03
影响因子：
6.4
通讯作者：
Pan Cheng-xiong;Zhang Jing-zhou;Shan Yong
中科院分区：
文献类型：
--
作者：
Pan Cheng-xiong;Zhang Jing-zhou;Shan Yong
数值研究了排气温度对装有一体化红外抑制器的直升机3-5μm波段红外信号的影响。利用CFD软件对直升机尾气的内部流动和外部下洗流动以及尾气与下洗的混合进行了数值模拟，以确定直升机蒙皮和排气羽流中的温度分布。基于表面和羽流的温度分布，采用前向后向射线追踪法计算了窄带模型直升机的红外辐射强度。结果表明，对于后机身嵌入红外综合抑制器的直升机，排气温度对羽流辐射特性有显著影响，而直升机蒙皮辐射强度影响不大。当排气温度从900K提高到1200K时，3-5μm波段的羽流辐射强度增加了约100%，而皮肤辐射强度仅增加了约5%。一般来说，排气温度对直升机红外辐射强度的影响主要集中在羽流上，特别是在皮肤发射率较低的情况下。
The effects of exhaust temperature on infrared signature (in 3–5 μm band) for a helicopter equipped with integrative infrared suppressor were numerically investigated. The internal flow of exhaust gas and the external downwash flow, as well as the mixing between exhaust gas and downwash were simulated by CFD software to determine the temperature distributions on the helicopter skin and in the exhaust plume. Based on the skin and plume temperature distributions, a forward–backward ray-tracing method was used to calculate the infrared radiation intensity from the helicopter with a narrow-band model. The results show that for a helicopter with its integrative infrared suppressor embedded inside its rear airframe, the exhaust temperature has significant influence on the plume radiation characteristics, while the helicopter skin radiation intensity has little impact. When the exhaust temperature is raised from 900 K to 1200 K, the plume radiation intensity in 3–5 μm band is increased by about 100%, while the skin radiation intensity is increased by only about 5%. In general, the effects of exhaust temperature on helicopter infrared radiation intensity are mainly concentrated on plume, especially obvious for a lower skin emissivity case.