Analysis of ultraviolet radiation characteristics of liquid propellant rocket motor exhaust plumes

Through the analysis of ultraviolet radiation mechanism of liquid propellant rocket motor exhaust plumes, a rocket motor plume ultraviolet radiation model was build, taking thermal emitting, CO+O chemiluminescence and OH radical chemiluminescence into consideration. Based on the separate calculation of flowfield and radiation transfer, the flowfield and radiation intensity distribution can be solved using 2-D and 3-D grids, respectively, which can save the computation time and get both of the spectrum of radiation intensity and the radiance at different angle of view distribution. The ultraviolet spectral radiation intensity as well as the two-dimensional radiance distribution at 90° angle of view of liquid hydrogen/liquid oxygen and kerosene/liquid oxygen bipropellant rocket motor plumes were calculated using the rocket motor plume ultraviolet radiation model, respectively. The influence of mixture ratio on ultraviolet radiation distribution of liquid bipropellant rocket motor plumes was studied by taking liquid hydrogen/liquid oxygen as an example. This study can provide reference for the analysis, design and optimization of ultraviolet early warning system, the judgment of missile types in the process of early warning, and the evaluation and improvement of missile ultraviolet stealth performance.