高空高速无人机尾焰红外辐射特性计算研究

Numerical simulation of infrared radiation characteristics for plume of the high-altitude and high-speed UAV

尾焰是高空高速无人机红外辐射源的主要组成部分,为了计算高空高速无人机尾焰的红外辐射特性,首先,利用流体仿真软件Fluent对高空高速无人机尾焰的流场进行了数值模拟,在此基础上,利用同时考虑谱线洛伦兹加宽效应和多普勒加宽效应的单线组谱带模型理论SLG以及机体遮挡理论,计算了高空高速无人机尾焰的红外辐射强度;其次,采用倾斜路径传输等效方法计算了大气对红外辐射的透过率;最后,计算并分析了某型高空高速无人机在发动机不同工作状态以及不同方位角和观察仰角条件下经过大气衰减后的红外辐射强度,同时分析了无人机飞行俯仰角对尾焰红外辐射强度的影响。

The plume is the main portion of the infrared radiation source for the high-altitude and high- speed UAV. To calculate the infrared radiation released from the plume of the high-altitude and high- speed UAV, a numerical simulation of the flow field for the plume of the UAV was firstly performed by using the software Fluent. And, according to the shelter theory of fuselage and the simple spectral band model theory SLG including the Lorentzian-broaden effects and the Doppler-broaden effects of the spectrum, the infrared radiation released from the plume of the high-altitude and high-speed UAV was calculated. Secondly, based on the method of slantwise route equivalent transport, the atmospheric transmittance of infrared radiation was computed. At last, infrared radiation intensity released from the plume of a high-altitude and high-speed UAV was calculated and analyzed after atmospheric attenuation under different work conditions of engine and at different azimuth and observational elevation. At the same time, the impact of pitch angle on the infrared radiation intensity was also analyzed.