Long time simulations of granular hydrodynamics : instabilities and attractors

TL;DR

This paper presents long-term simulations of 2D granular flows using hydrodynamic models, revealing metastable clustering and eventual attraction to shear or vortex states, aligning with molecular dynamics results.

Contribution

It introduces extensive long-time hydrodynamic simulations of granular flows, highlighting the transition from metastable clusters to stable shear or vortex attractors.

Findings

Metastable clustering occurs at intermediate times.

System evolves to shear band or vortex states over longer times.

Results agree with molecular dynamics simulations.

Abstract

Using a hydrodyamic model of granular flows, we present very long time simulations of a granular fluid in two dimensions without gravity and with periodic boundary conditions in a square domain. Depending upon the values of the viscosity, thermal conductivity and dissipation, we find for intermediate times a metastable clustering state. For longer times the system is attracted to either a shear band or a vortex state. Our results are in general agreement with molecular dynamics simulations.