Modeling of Thermochemical Nonequilibrium Flows Using Open-Source Direct Simulation Monte Carlo Kernel SPARTA

Chemical reactions are usually coupled with transfer of internal energies in high-temperature gas and have been an ongoing challenge for the direct simulation Monte Carlo (DSMC) method. In this paper, three typical reaction models are compared quantitatively, and the impact of vibrational favoring effects as well as three-body recombination are analyzed. The recently developed open-source DSMC kernel SPARTA is employed and modified in the present study. The verification results indicate that the SPARTA code produces a satisfactory description of the nonequilibrium reacting flow. A further application is made to the hypersonic nonequilibrium boundary-layer flows past an obstacle. It is found that SPARTA is in excellent agreement with continuum-based method for the low-altitude condition (H 50 km); however, considerable differences arise at high altitudes (H 70 km) due to locally rarefied gas effects.