Hybrid Continuum/Rarefied Flow Simulations of Plume Interaction with Full-Sized Spacecraft

Abstract

The present study performs hybrid Navier–Stokes (N-S) and direct simulation Monte Carlo (DSMC) simulations to predict surface pressures and heat fluxes imposed by plumes impinging on spacecraft in actual length scale. The first application was the impingement of H-II Transfer Vehicle main engine plumes on the International Space Station. It was found that the profiles of the surface pressure and heat flux imposed by the plume interactions strongly depend on the high-density regions generated by the interactions among multiple plumes and between plumes and upstream structures. The plume of a lunar lander was another application. A plume impinging on the lunar surface generated a strong shock wave near ground level, and some of the hot gases imposed larger pressures and heat fluxes as the altitude decreased. The third application was a cold-gas plume vented from rocket tanks. Although the nozzles were small, plumes expanded rapidly and subjected some rocket assemblies to various forces and cooling effects. Last, the last application to a thruster plume impinging on debris showed that the plume can impart enough torque to detumble the rotation of a debris. This study adequately demonstrated that the usefulness of the hybrid N-S/DSMC technique for assessing risks or exploring new ideas regarding plume impingement in actual spacecraft length scale, including the plume–plume and plume–surface interactions.