Research On The Combined CFD-DSMC Method For Hybrid Particle-Continuum Flow

According to the value of Knudsen Number, the flow region can be divided into continuum region, transition region and particle region. There are especial numerical algorithms for different flow regions. The methods to solve the NS equation have been developing for many years and the validity of different algorithms have been accepted widely, as well as the DSMC method used in rarefied gas dynamic. The purpose of this dissertation is to improve upon the numerical simulation tools currently available to model hypersonic, multi-scale gas flow.Firstly, the finite volume approach to solve N-S equation is briefly introduced. The program’s availability has been validated by previous researchers through prior work. DMSC method is be employed to describe the rarefied flow. Both of the programs are modified to adapt for hybrid particle-continuum method.Secondly, the components used in this hybrid particle-continuum method are described. Such components include the specific numerical methods used to solve both DSMC and NS regions, calculation of continuum breakdown parameter, mesh managing procedures, and a module that transfers information between particle and continuum regions.Finally, the hybrid method is used to simulate 1D normal shock wave. The hybrid numerical cycle is described. Hybrid results are compared with pure NS simulations, pure DSMC simulations.