Sandpiles on fractal bases: pile shape and phase segregation

TL;DR

This paper explores how fractal bases influence sandpile structures, revealing complex ridge formations and phase segregation phenomena through experimental and numerical studies, advancing understanding of granular flow behavior on irregular boundaries.

Contribution

It introduces the study of sandpiles on fractal bases, demonstrating effects on pile shape and phase segregation, which is a novel approach in granular physics research.

Findings

Fractal bases induce complex ridge and valley formations.

Valleys exhibit a screening effect influenced by the angle of repose.

Binary systems show significant phase segregation along valleys.

Abstract

Sandpiles have become paradigmatic systems for granular flow studies in statistical physics. New directions of investigations are discussed here. Rather than varying the nature of the pile (sand, salt, rice,..) we have investigated changes in the boundary conditions. We have investigated experimentally and numerically sandpile structures on bases having a fractal perimeter. This type of perimeter induces the formation of a quite complex set of ridges and valleys. A screening effect of the valleys is observed and depends on the angle of repose. Binary granular systems have also been investigated on such bases: a spectacular demixing is obtained along the valleys. This type of phase segregation is discussed with respect to numerical studies.