A 3D Arbitrary Lagrangian Eulerian Adaptive Mesh Refinement Framework for Simulating Hypersonic Raindrop Impacts

Hypersonic vehicles operating in adverse weather conditions experience significant aerodynamic heating and mechanical stresses exacerbated by high-speed rain droplet impacts. These impacts can lead to erosion, structural damage to thermal protection systems (TPS), and ultimately, degraded aerodynamic performance. The complex interaction involves droplet distortion due to oblique shock interactions, subsequent impacts at oblique angles, debris generation from both the droplet and TPS material, and the cascading effects of multiple impacts. Accurately predicting these phenomena requires efficient, three-dimensional (3D) multiphysics simulations capable of resolving the multi-material interfaces and dynamic processes involved. Current modeling approaches, often limited to two dimensions (2D), lack the necessary fidelity and efficiency to comprehensively capture these intricate interactions. This work details the development of a novel 3D computational framework designed to address this critical gap. We show how to use Lagrangian-Eulerian techniques to integrate advanced capabilities for modeling droplet-shock interactions, droplet impact physics, debris-droplet dynamics, erosion/damage modeling, and aerodynamic performance analysis within a single, efficient computational environment. We show new validated results on the interaction of droplets with shocks for a range of droplet sizes and shock speeds. We show initial simulation of complete modeling of a Cu flyer plate producing a bow shock that interacts with a water droplet prior to impacting the plate.