Hypersonic CFD is challenging because the governing PDEs are pathologically stiff, physics models are inadequate for extreme operating conditions, data for validation is scarce, and vehicle-level simulations push the limits of software and hardware.
Nonequilibrium Gas Dynamics: Modeling of shock dynamics and shock-shock interactions.
Rarefied-to-Continuum Bridging: Coupling kinetic and continuum processes via adaptivity in numerical methods, computational meshing, and physics models.
Gas-Surface Interface and Materials Response: Include ablation, oxidation, and surface chemistry under hypersonic heating.
Multiscale and Multiphysics Coupling: Integrate high-temperature gas dynamics and heterogeneous chemistry
System-level Uncertainty Quantification: Assess the propagation, transmission, evolution, and interactions of uncertainties from components of a complex system in space and time to the system.
Hypersonic CFD is fun because it pushes every concept that we learn to its limits - turning theory into discovery.