Avalanche Merging and Continuous Flow in a Sandpile Model

TL;DR

This paper investigates a sandpile model revealing a dynamical transition from intermittent to continuous flow, characterized by scaling laws and diverging active zone width, with implications for understanding granular flow dynamics.

Contribution

It introduces a detailed analysis of the transition between flow regimes in a sandpile model, including scaling functions and the relationship between flow rate and slope change.

Findings

Active zone width diverges in avalanche regime

Mean slope change scales as r^{1/θ}

Scaling behavior characterized by nontrivial exponents

Abstract

A dynamical transition separating intermittent and continuous flow is observed in a sandpile model, with scaling functions relating the transport behaviors between both regimes. The width of the active zone diverges with system size in the avalanche regime but becomes very narrow for continuous flow. The change of the mean slope, Delta z, on increasing the driving rate, r, obeys Delta z ~ r^{1/theta}. It has nontrivial scaling behavior in the continuous flow phase with an exponent theta given, paradoxically, only in terms of exponents characterizing the avalanches theta = (1+z-D)/(3-D).