Development of a multi-species, parallel, 3D Direct Simulation Monte-Carlo solver for rarefied gas flows

A new multi-species, polyatomic, parallel, three-dimensional Direct Simulation Monte-Carlo (DSMC) solver is developed in this work for applications related to rarefied gas flows. The validation results of our DSMC solver, named as the “Non-equilibrium Flow Solver (NFS)”, are presented in this article. The main features of the NFS solver include its ability to handle multi-species, polyatomic gases for 2D/3D steady and transient nature of flow problems over arbitrary geometries, with a density based grid adaptation technique. Furthermore, 3D surface refinement (for accurate calculation of surface properties) and 3D gas-surface interaction is implemented in a very efficient manner in the solver. The macroscopic flow properties and surface properties, such as heat flux, pressure distribution, drag, can directly be obtained from the solver. The NFS solver is validated for seven test cases related to different two and three dimensional external flow problems of both transient and steady nature. The results obtained using the NFS solver are found to agree very well with both experimental data and those obtained in other numerical works.