Assessment of the Influences of Numerical Models on Aerodynamic Performances in Hypersonic Nonequilibrium Flows

Abstract

In this paper, the aerodynamic performances including shock wave standoff distance (SSD) and heat flux of ELECTRE vehicle at 53.3 km and 4230 m/s for several types of numerical models are investigated. The numerical models include thermal equilibrium/nonequilibrium (1T/2T) assumption, three surface boundary conditions (no-slip/non-catalytic, slip/non-catalytic, slip/fully-catalytic), four chemical kinetic models (DK, Park, Gupta, and No Reaction (NR)) and two controlling temperatures (Ttr0.7Tve0.3, Ttr0.5Tve0.5). The results show that the chemical kinetic model significantly affects the SSD, and its value gradually decreases with the increase in chemical reaction rate. The SSD predicted by the NR model is 20.7% larger than that of the Park model. The SSD is also affected by the proportion of vibro-electronic temperature (Tve) in the controlling temperature, and the higher the proportion, the larger the SSD. Regarding the heat flux, the catalytic surface setting is crucial, where the value predicted by the fully-catalytic model is 62.2% higher than that by the non-catalytic model. As the chemical reaction rate of Gupta, DK, and Park models increases sequentially, the calculated heat flux decreases in turn. The heat flux predicted by the 2T model is lower than that by the 1T model, and the higher Tve proportion in the controlling temperature, the smaller the heat flux. The fundamental reason is that the trans-rotational convective heat flux of the 2T model is much lower than that of the 1T model, and the trans-rotational convective heat flux decreases with an increase in the Tve proportion.