DSMC Simulation of Rarefied Gas Flow over a Backward- Facing Step: Effect of Expansion ratio

Abstract

Numerical simulations have been performed to study the effect of expansion ratio on the hypersonic rarefied flow past a backward-facing step. The Direct Simulation Monte Carlo (DSMC) method is used for the present study. An opensource solver named dsmcFoam has been used for this purpose. The solver has been validated with well-established results from the literature and good agreement is found among them. Simulations have been carried out for expansion ratios (ER) of 2,4,6,8,10 in the transition regime. The different flow field properties such as velocity, pressure and temperature have been studied. The profiles have found to be influenced by the compressibility and rarefaction effects. Limiting case of ER=8 and above has no influence on the flow field properties.

DSMC simulation of rarefied gas flow over a 2D backward-facing step in the transitional flow regime: Effect of Mach number and wall temperature

“…The present numerical simulations are carried out using the dsmcFoam solver, in which the validity of the solver has been thoroughly established in our recent works. 78–82 However, a benchmark case of hypersonic flow past a flat plate is used in the present work to establish the applicability of the DSMC method. The flat plate has a relatively simple geometry having both experimental results by Becker et al.…”