Numerical study of shock/vortex interaction in diatomic gas flows

Abstract

The particle-based direct simulation of Monte Carlo(DSMC) was present and validated for the investigation of non-equilibrium effects in diatomic gas flows. All the validations show that the results of the present DSMC is in agreement with the experimental data. Then, the numerical studies of micro scale shock/composite-vortex interactions in diatomic gas flows were conducted. The substantial attenuation of enstrophy in diatomic gas flow is observed. Differ from the sharp decreasing in diatomic gas, the time evolution of enstrophy in monatomic gas flow decrease linearly in the whole process. This study also shows that the vortex deformation through a shock, in particular, is observed to be strongly dependent on the shock and vortex strengths. Also, it is also found that strong interaction can also cause vorticity production in microscale shock/vortex interaction for diatomic gas flow. The attenuation, analogous to DSMC results, overwhelms the vorticity generation only in a limited set of regimes with low shock Mach number, small vortex size, or weak vortex. Besides, in diatomic gas flow, viscous vorticity generation is also most dominant in the three dynamical processes of vorticity transportation, followed by dilatational and baroclinicvorticity generation. The present study conform that shock/vortex present different features in strong and weak interactions for monatomic and diatomic gas flows. Furthermore, it provides a new way for the investigation of non-equilibrium effects.