On an Axisymmetric Direct Simulation Monte Carlo Method

This study proposes an application of the variable time step (VTS) method to solve the non-conservation of fluxes encountered in the conventional direct simulation Monte Carlo (DSMC) method in axisymmetric simulations. A legacy parallel DSMC code with an unstructured cell using C(++)language (PDSC++) was employed by adjusting the reference scale of the original VTS to fulfill the requirements of axisymmetric simulation. Three test cases were simulated to verify the proposed axisymmetric DSMC method. First, the hypersonic flow past a cylinder was simulated using different wall boundary conditions. Second, the hypersonic flow past a 1.6-m sphere was simulated considering complicated air chemistry. Third, the flow field of the hypersonic flow past a double-cone blunt body was simulated and compared with the experimental data. The results showed that the newly proposed axisymmetric DSMC method can meet the simulation accuracy without an inconvenience through particle cloning and destruction.