Improved Direct Simulation Monte Carlo method for solving modern problems of rarefied gases dynamics

TL;DR

This paper enhances the DSMC method for simulating rarefied gases by introducing new schemes that improve performance, reduce computational demands, and enable more efficient simulations of complex gas dynamics problems.

Contribution

The paper introduces novel schemes and approaches, including variable time steps and collision detection, significantly improving DSMC efficiency and applicability to modern computational problems.

Findings

Improved simulation performance and reduced resource usage.

Effective handling of multi-component gas mixtures.

Enhanced algorithms for axisymmetric and stationary problems.

Abstract

First of all, this paper presents some improvements of DSMC method in the form of new schemes and approaches, that, for a wide class of problems, increase performance and reduce the demands on computer resources. The most important improvement is the scheme of temporal factors, allowing the use of different time step for different sorts of particles, thus reducing the complexity and/or resource usage in simulation of stationary problems with very different collisional cross-sections between components of a mixture. Other improvements include the similarity parameter for efficient estimation of the number of simulational particles required for 1D, 2D and 3D computations, the new scheme for solving axisymmetric problems, an approach to detect and reject repetitive collisions. Also, some advice on technical optimization of algorithm for modern computers is offered.