DSMC Modeling of Internal Energy Excitation and Dissociation of Molecular Nitrogen in Hypersonic Reentry Flows

The current work implemented in DSMC vibrational excited levels of N2 and transitions between the levels as well as the dissociation of nitrogen molecules from different levels. Results show that due to insufficient collisions, the flow around a sphere at 70/75 km altitudes has a high degree of nonequilibrium in the vibrational mode where the ground level is separated from the higher levels. The continuum‐level calculation results are different from the work of Candler and the nonequilibrium profile predicted by the discrete‐level calculation is also different.