Рост плотности и расхода тяжелого компонента при истечении разреженной газовой смеси в вакуум

Gas dynamics of a rarefied mixture flowing from a chamber into vacuum is studied for the case of disparate-mass components. The modeling was fulfilled by the DSMC method. An increase of the heavier component density is observed in the vicinity of the chamber’s outlet. A significant impact of the lighter component on the jet dynamics consists in an increase of the heavier component flux and direction of heavier particles to the axis.

Employing Per-Component Time Step in DSMC Simulations of Disparate Mass and Cross-Section Gas Mixtures

A new approach to simulation of stationary flows by Direct Simulation Monte Carlo method is proposed. The idea is to specify an individual time step for each component of a gas mixture. The approach consists of modifications mainly to collision phase simulation and recommendations on choosing time step ratios. It allows lowering the demands on the computational resources for cases of disparate collision diameters of molecules and/or disparate molecular masses. These are cases important e.g., in vacuum deposition technologies. Few tests of the new approach are made. Finally, the usage of new approach is demonstrated on a problem of silver nanocluster diffusion in argon carrier gas under conditions of silver deposition experiments.