A direct simulation Monte Carlo approach on the Riemann problem for gas mixtures

Abstract

The Direct Simulation Monte Carlo method is employed to solve the “1D - Sod-Shock tube problem”, a special case of Riemann problems, for gas mixtures. Initially, two different gas species are distributed separately in the high and low pressure sides of the tube without interacting with each other. For time greater than zero the species start mixing and shock and rarefaction waves are formed moving in opposite directions. In this work, the mixing process between different kinds of gas species was investigated by observing differences in waves’ formation. The influence of the mass and diameter ratio between the species was studied in detail. It was found that greater mass differences had a very strong effect on the mixing process, while the effects due to diameter differences were relatively small. Finally, it is shown that in the case of single species the interaction molecular models of the hard sphere, the variable hard sphere and the variable soft sphere gave the same results, while for gas mixtures the variable hard sphere and variable soft sphere models gave slightly different results.The Direct Simulation Monte Carlo method is employed to solve the “1D - Sod-Shock tube problem”, a special case of Riemann problems, for gas mixtures. Initially, two different gas species are distributed separately in the high and low pressure sides of the tube without interacting with each other. For time greater than zero the species start mixing and shock and rarefaction waves are formed moving in opposite directions. In this work, the mixing process between different kinds of gas species was investigated by observing differences in waves’ formation. The influence of the mass and diameter ratio between the species was studied in detail. It was found that greater mass differences had a very strong effect on the mixing process, while the effects due to diameter differences were relatively small. Finally, it is shown that in the case of single species the interaction molecular models of the hard sphere, the variable hard sphere and the variable soft sphere gave the same results, while for gas mixtures the...