AN EVALUATION OF ROES SCHEME GENERALIZATIONS FOR EQUILIBRIUM REAL-GASFLOWS

The extension of Roe's approximate Riemann solver to equilibrium real gas is analyzed by means of a general formulation, allowing us to clar ify the inherent nonuniqueness of the average state and the influence of the functional form of the equation of state, Several generalizatio ns of Roe's scheme are then reviewed and their numerical performances are discussed by computing some 2D steady hypersonic flows. The flow s olvers are coupled with a newly developed, efficient, and robust proce dure for thermochemical air properties evaluation. All of the tested e quilibrium solvers achieve very similar results. They are found of com parable numerical efficiency, the higher performances being associated with Vinokur's and Liou's solvers. It is concluded that equilibrium s imulations in 2D are by no means less robust than the perfect gas ones , when coupled with the proposed procedure for properties evaluation. (C) 1997 Academic Press.