CFD-DEM Coupled Simulation for Plume Surface Interaction and Soil Erosion During Spacecraft Landing

Some of the key challenges associated with human missions to the Moon and Mars are related to rocket exhaust effects and lunar landing blasts. Regolith behavior could unpredictably vary based on gravity conditions. In addition, high speed plumes not only cause escape of lunar soil particles and potential damage to lunar orbiters but also leave severe erosion on the lunar surface itself. Unlike terrestrial erosion, lunar soil erosion does not involve saltation (particles bouncing along the surface), rather it is dominated by a viscous erosion mechanism. In this paper, we study the effect of lander engine plumes with lunar surfaces to minimize potential damage to surrounding hardware and increase the safety of lunar infrastructure. We combine the finite volume method for capturing the plume impingement and discrete element method for soil particles. Regolith erosion is studied for lander exhaust plume and lunar surface where we account for the cohesive strength of the soil. In addition, the dependency of crater morphology on different gravitational conditions and Mach number is investigated.