Investigation of Regolith Erosion and Crater Formation during Lunar Landing using an Eulerian-Lagrangian Approach.

The phenomenon of jet-induced cratering in granular beds has garnered significant interest due to its relevance in both natural and industrial settings. Existing literature on crater formation lacks sufficient detail to fully understand the underlying physical processes and develop predictive models for plume impacts. This study aims to enhance existing models and establish mitigation strategies to ensure the safety of future lunar missions by implementing computational simulation capability for the a reliable prediction of surface erosion and crater formation due to plume surface interaction (PSI) during lunar landing. The main objective of this study is to utilize simulations to explore the morphological features of the crater and their temporal evolution. Numerical analysis is performed employing a novel model integrating computational fluid dynamics (CFD) for the gas phase and the discrete element method (DEM) for the solid phase. Utilizing data from Apollo descent recordings, terrain photos, and ascent footage, this research investigates various phenomena such as regolith bed formation, regolith erosion, crater formation and characterization of ejecta properties. The study presents a comprehensive, axisymmetric simulation of plume-induced erosion and crater formation caused by a lunar lander at different plume impingement heights above the lunar surface, in near-vacuum conditions. Sample result, showing flow fields of gas and ejected particles. The study provides insights crucial for lunar landing safety and mission planning.