Infrared Spectral Characteristic Analysis And Image Simulation Of Engine Exhaust Plume

The early warning,tracking and identification in the infrared band is a n effective target detection method.The engine wake,with its strong radiation characteristics and strong spectral characteristics,has become the main object of infrared warning and identification of aircraft targets.According to the imaging relationship,the target infrared spectrum radiation image at the entrance pupil surface of the detector is calculated.Based on this,the spatia l distribution characteristics,energy distribution characteristics,and the variation law of the target radiation are analyzed,which is a common method for carrying out research on the infrared characteristics of the target.With the improvement of hardw are level,GPU is widely used in scientific research with its excellent parallel computing capabilities,which can effectively improve the efficiency of target infrared radiation and imaging calculations.In this paper,the infrared radiation calculation method for 3D wakes is studied.Based on GPU parallel computing,a target infrared imaging calculation model is established and validated.Based on this analysis,the spatial distribution of the engine wake radiation and the variation of energy distribution with altitude are analyzed.As well as the changes in the radiation characteristics of the wake after reactivation,the specific work is as follows:The wake gas was established using the statistical narrow-band model,and the optical radiation property database of the wake particles was established using the Mie theory.The radiation propagation equation was solved using the single line group model and the line of light method,and the solar scattering based on single scattering was established.The radia tion algorithm realizes the infrared radiation calculation of the three-dimensional wake.A forward calculation method is used to calculate the projection of the bod y radiation,and a backward calculation method is used to calculate the wake radiation imaging.The Monte Carlo method is used on the body and the near-body encryption method is used on the wake to improve the calculation accuracy.Thus,the target infrared imaging calculation software is established.,and use CUDA parallel in the coordinate transformation,bin projection,spectral radiation calculation and other modules to improve the calculation speed.The infrared characteristics of the wakes of the two missiles at a height of 1 to 100 km were calculated using the established infrared imaging software.The spectral radiation of the wakes,the radiation intensity of each band,and the variation of the wake core area with height were analyzed.The infrared characteristics of the re-combustion wake and frozen-end flow in the 1~50km altitude were contrasted and analyzed.The difference in the infrared radiation distribution and energy distribution between the two was compared.The contrast of infrared radiation between the wake of a typical band and the earth's background was analyzed,and the detectability of the wake was studied.The research results of this paper have some reference significance for the detection and recognition of the target.