Simulation and Analysis of Influence of Vacuum Back Pressure Environment on Laser Thruster

The paper presents a simulation physical model of laser thruster under vacuum back pressure environment. Through the finite difference method and the Direct Simulation Monte Carlo (DSMC) calculation method, based on the actual laser thruster structure and working mode, the changes of the flow field distribution in the laser thruster plume under different vacuum back pressure conditions are obtained. The influence of different vacuum back pressure conditions on the plume density field and velocity field of the thruster was verified through physical experiments, and the evolution process of the plume flow field during laser ablation of polyamide glycidyl ether (GAP) solid target material was analyzed in detail. The simulation results are in good agreement with the test results, and the deviation between the simulated data and the test data from 0 to 3000ns is less than 10.4%. It presents a foundation for the prediction model of laser thruster under vacuum environment, and provides an important reference for ground test and in-orbit application of satellite laser propulsion system.