Comparison of DSMC and Merged Shock-layer Analyses of the Flow around a Reentry Body at a High Altitude

Abstract

DSMC analysis was conducted for the flow around a reentry body at a high altitude about 80km. Gas particles were described by the VSS (Variable Soft Sphere) model, and three energy modes, namely translational, rotational, and vibrational energy modes were taken into account. Assuming pure nitrogen gas, five chemical species model and four chemical reactions model were applied. The NTC model suggested by Bird was used for particle collisions. For vibrational relaxation, Millikan-White's empirical formula was used with Park's high-temperature correction. Calculation was made for the reentry conditions of OREX (Orbital Reentry Experiment) and AOTV (Aeroassisted Orbital Transfer Vehicle) with the Mach number of 25 to 40, and compared with the extended merged shock-layer analysis only along a stagnation streamline. The results clarified the nonequilibrium properties of the flows.