Abstract:
Recent advances in hypersonic technologies, driven by space exploration and commercial activities, have motivated the need for accurate modeling of the interaction between hypersonic flow and the entry object. At the same time, the atmospheric entry of large meteoroids and space debris presents additional challenges, with planetary-defense scenarios representing an important class of hypersonic flow–material interaction problems.

These challenges arise from coupled multiphysics and multiscale phenomena: high-enthalpy effects (chemical and thermal nonequilibrium), radiative transfer, gas–surface interaction, and material response. However, despite many decades of progress, predictive capabilities remain limited, particularly for flow–material coupling.

This seminar provides an overview of multiphysics and multiscale modeling approaches for hypersonic entry, with particular emphasis on applications including meteoroid atmospheric entry and spacecraft thermal protection systems.

We present two coupling strategies. In the unified coupling approach, flow and material are solved in a single computational domain. This allows the interface to be treated naturally without imposing boundary conditions. In the two-way (loosely) coupling approach, the flow and material domains are coupled through an iterative exchange of information at their respective boundaries. This latter method is more suitable for large-scale hypersonic simulations due to temporal scale separation. 

Together, these approaches establish a consistent modeling framework that links fundamental physical processes to engineering-scale predictions for both natural and engineered entry systems.

Bio:
Dr. Bruno Dias is a researcher at NASA Ames Research Center working on multiphysics and multiscale modeling of hypersonic flow–material interaction. Research applications include thermal protection systems, space debris, and meteoroid entry. He received his PhD from the Université catholique de Louvain (UCLouvain) and the von Karman Institute for Fluid Dynamics (VKI) in 2020 on thermal ablation and radiation modeling of meteor phenomena.

His interests are hypersonic aerothermodynamics, radiative transfer, gas–surface interactions, and porous-media modeling, with an emphasis on high-fidelity numerical simulation and multiphysics coupling.

He is a member of the AIAA Thermophysics Technical Committee, chairing the education subcommittee, and serves on the scientific committee of the International Symposium on AI and Fluid Mechanics (AIFLUIDs).