Hybrid continuum/DSMC computation of rocket mode lightcraft flow in near space with high temperature and rarefaction effect

In this paper, we consider laser propulsion operating in near space (altitude of 20–100 km) where the ambient gas is rarefied . For the rocket mode, a dense gas is injected into the focused region to generate high temperature plasma by laser beam focusing. A hybrid continuum/DSMC method is used to simulate the unsteady high temperature continuum flow coupled with the rarefied ambient air. An order of magnitude analysis, based on a simplified physical analysis, is provided for the impulse coupling coefficient and specific impulse. For the rocket mode studied here, a specific impulse of 855 s is obtained.