An adaptive timestepping methodology for particle advance in coupled CFD-DEM simulations

TL;DR

This paper introduces an adaptive local time stepping method for particle simulation in coupled CFD-DEM models, significantly reducing computational costs while preserving accuracy in systems with varying collision scales.

Contribution

The work presents a novel local time stepping algorithm that selectively advances particles near collisions, improving efficiency over traditional explicit methods in CFD-DEM simulations.

Findings

Achieves 2-3X speedup compared to explicit methods.

Maintains accuracy in dense and dilute particle regions.

Effectively resolves multiscale collision dynamics.

Abstract

An adpative integration technique for time advancement of particle motion in the context of coupled computational fluid dynamics (CFD) - discrete element method (DEM) simulations is presented in this work. CFD-DEM models provide an accurate description of multiphase physical systems where a granular phase exists in an underlying continuous medium. The time integration of the granular phase in these simulations present unique computational challenges due to large variations in time scales associated with particle collisions. The algorithm presented in this work uses a local time stepping approach to resolve collisional time scales for only a subset of particles that are in close proximity to potential collision partners, thereby resulting in substantial reduction of computational cost. This approach is observed to be 2-3X faster than traditional explicit methods for problems that involve both dense and dilute regions, while maintaining the same level of accuracy.