Evaluation of Viscous Flow Solvers with Adaptive Cartesian Meshes for Hypersonic Flows

摘要

The present work seeks to advance and document the ability of Cartesian grid based formulations to model hypersonic viscous flows. This capability is investigated in the adaptive Cartesian mesh solvers, NASCART-GT and UFS. The effectiveness of the immersed boundary ghost cell method in these solvers to model viscous effects in hypersonic non-reacting flow is investigated. In addition, the viscous, chemically reacting flow capability is developed, installed, and tested into the Cartesian framework in the NASCART-GT code. This thermochemical nonequilibrium methodology accounts for temperatures associated with the equilibrated translational-rotational modes and the vibrational-electronic modes. Viscous diffusion terms are added to the species and energy conservation equations, and collision cross-section based transport coefficients are implemented. Initial comparisons of skin-friction coefficients and surface heat transfer predictions in a non-reacting, viscous environment are conducted. In addition, comparisons of off-surface flow features in a reacting, viscous environment are performed.