Numerical simulation of air-breathing nanosecond laser propulsion considering subsonic inflow and multi-pulse

The model of paraboloid point focusing laser thruster is adopted to investigate numerically the air-breathing nanosecond laser propulsion under subsonic inflow and multi-pulse condition. The influence of pulse number and subsonic inflow on propulsive performance is analyzed. The simulation results indicate that the average impulse coupling coefficient Cmn decreases significantly with the increasing of pulse number because the air in the nozzle cannot recover to the initial state, but the trend becomes smooth due to the similar flow field before subsequent pulse. When the Mach number increases, the multi-pulse Cmn falls down at the same number of laser pulse. It shows that the faster subsonic inflow, the higher air drag and the shorter time of interaction between the shock wave and the thruster.