Surface Shape of Two-Dimensional Granular Piles

TL;DR

This paper combines experiments and continuum theory to analyze the surface shape of 2D granular piles, revealing how material properties and grain drift velocity influence the formation of curved tails.

Contribution

It provides an analytical solution to the BCRE equations for granular surface flows, linking theoretical predictions with experimental observations.

Findings

Analytical solution matches experimental surface shapes.

Curved tails depend on material properties and grain drift velocity.

Surface shape predictions are in good agreement with experiments.

Abstract

We study the surface shape of two-dimensional piles using experiments and a continuum theory for surface flows of granular materials (the BCRE equations). We first obtain an analytical solution to the BCRE equations with a simple transformation and show that the surface shapes thereby predicted are in good agreement with the experimental results. By means of such an analytical solution, we find that the formation of the curved tails at the bottom of such piles depends not only on the properties of the granular materials but also on the drift velocity of the grains within the rolling layer.