Detectability Analysis Of The Ultraviolet Radiation Of Typical Rocket Exhaust Plume

Rocket exhaust plume is a kind of high-speed,high-temperature,multi-component free jet.After the propellant is burned in the combustion chamber,it is discharged into the environment through the process of nozzle accelerating expansion.Under the action of high-speed inflow,the exhaust plume interacts with the atmosphere,and the exhaust plume is rich in fuel components,which leads to combustion.In the process of fuel combustion,a plume like flow field of light-emitting flame will be formed in the air,commonly known as rocket exhaust plume.UV early warning system is to obtain UV radiation from missile plume and particles,so as to realize the purpose of timely warning for missiles.At present,it has extremely important application requirements in aerospace,military confrontation,civil monitoring and other fields.Therefore,it is of great significance to study the mechanism and detectability analysis of engine exhaust plume UV radiation.Based on the application background of space-based UV early warning,this paper focuses on the mechanism and detectability of plume ultraviolet radiation.Taking the exhaust plume of two engines as the research object,the modeling of plume flow field UV radiation characteristics,the simulation of atmospheric background UV radiation characteristics and the analysis of plume UV radiation detectability under typical working conditions are carried out.The main contents of this paper are as follows:(1)Through the independent modeling and simulation,the ultraviolet spectral radiance data of solid/liquid rocket exhaust plume is calculated,and the characteristics of ultraviolet radiation spectrum of rocket exhaust plume at different flight heights are analyzed.(2)The calculation and analysis of the characteristics of the background ultraviolet radiation of the earth's atmosphere are carried out,and the quantitative data of the atmospheric transmittance and background radiation intensity under different wave bands,seasons,aerosols,solar angles and ground types are obtained.(3)Based on the assumed detection scene,the detection range of the exhaust plume at different wave band and height is obtained,and the best detection wave band is obtained based on the relationship between the target and the background.