Particle number per cell and scaling factor effect on accuracy of DSMC simulation of micro flows

Abstract

Purpose - This paper aims to give some guidance on the selection of particle numbers per cell and the number of molecules per particle in the micro flow simulation by using DSMC method. Design/methodology/approach - The numerical investigation is performed to study the effects of particle number per cell and the scaling factor of real molecules to a simulated particle on accuracy of DSMC simulation of two-dimensional micro channel flows in the "slip flow" and "transition flow" regimes. Findings - Numerical results show that both the particle number per cell and the scaling factor have effect on the accuracy of the DSMC results from the statistical error and the physical aspects. In the "slip flow" regime, a larger value of scaling factor can be used to obtain accurate results as compared to the "transition flow" regime. However, in the "transition flow" regime, much less number of particles in each cell can be used to generate accurate DSMC results as compared to the "slip flow" regime. Research limitations/implications - The present work is limited to the two-dimensional case. Practical implications - The results of this paper are very useful for the two-dimensional micro flow simulation by DSMC. Originality/value - The work in this paper is original and provides guidance on micro flow simulation. © Emerald Group Publishing Limited.