Unified Kinetic/Continuum Flow Solver with Adaptive Cartesian Mesh for Hypersonic Flows in the Earth Atmosphere

The design of future hypersonic vehicles requires detailed understanding of flow regimes ranging from rarefied to continuum. Moreover, hypervelocity flows are characterized by high temperatures, excitation of vibrational level of molecules, nonequilibrium dissociation, and ionization. The goal of this project is to develop unified kinetic/continuum solution methods with proper domain decomposition for a wide range of Air Force Applications. The Unified Flow Solver (UFS) with Adaptive Mesh and Algorithm Refinement, developed by CFDRC, will be enhanced by the advanced capabilities of the NASCART-GT viscous flow solver from Georgia Tech, and demonstrated for viscous/inviscid problems covering rarefied and continuum flow regimes. The octree based Cartesian mesh methods will be improved to better resolve viscous boundary layers and heat transfer simulations near surfaces. Phase I work will demonstrate the feasibility of kinetic/continuum algorithms with Cartesian mesh to compute heat transfer for dissociating and ionizing hypersonic flows. During Phase II, the advanced numerical techniques will be incorporated into a user-friendly code, and a general-purpose chemistry module and turbulence models will be added to the continuum solvers. The code will be validated for heat transfer simulations with Cartesian mesh and demonstrated for several benchmark cases including heat transfer prediction on a Mach 16 flow over bi-conic body.