Temporally heterogeneous dynamics in granular flows

TL;DR

This paper investigates the complex, time-dependent behaviors of dense granular flows, revealing intermittent dynamics and large-scale structural events as the system approaches the angle of repose, drawing parallels with supercooled liquids near glass transition.

Contribution

It introduces a detailed analysis of temporally heterogeneous dynamics in granular flows, highlighting intermittent behavior and structural correlations near the stopping threshold.

Findings

Dynamics become intermittent near the angle of repose.

Large-scale contact network spanning events occur periodically.

Characteristic timescales increase as the flow approaches cessation.

Abstract

Granular simulations are used to probe the particle scale dynamics at short, intermediate, and long time scales for gravity driven, dense granular flows down an inclined plane. On approach to the angle of repose, where motion ceases, the dynamics become intermittent over intermediate times, with strong temporal correlations between particle motions -- temporally heterogeneous dynamics. This intermittency is characterised through large scale structural events whereby the contact network periodically spans the system. A characteristic time scale associated with these processes increases as the stopped state is approached. These features are discussed in the context of the dynamics of supercooled liquids near the glass transition.