Effects of Chemistry in Nonequilibrium Hypersonic Flow Around Blunt Bodies

In this paper, the influence of a chemical kinetic model in hypersonic flow past blunt bodies is examined. Slow and fast chemical kinetic models are investigated to identify the reliable model for applications with a wide range of Mach numbers. Solutions from the Gardiner reaction-rate set, the Moss reaction-rate set, the Park rate set of 1993, and the Dunn and Kang reaction rate are compared. High-temperature, equilibrium-constant curve fits proposed by Gupta are also examined. The new Hansen's formulation for the rate controlling temperature for the dissociation reaction is compared with Park's approach. Particular attention has been devoted to backward reaction rates, because the methods of calculation affect the flowfield structure. Sample hypersonic flowfields, typical of spacecraft reentry conditions in which reactions play an important role, are presented and compared with results from experiments and other computational fluid dynamics simulations. The differences are discussed and evaluated.