Sandpile formation by revolving rivers

Abstract

Experimental observation of a new mechanism of sandpile formation is reported. As a steady stream of dry sand is poured onto a horizontal surface, a pile forms which has a thin river of sand on one side flowing from the apex of the pile to the edge of its base. The river rotates about the pile, depositing a new layer of sand with each revolution, thereby growing the pile. For small piles the river is steady and the pile formed is smooth. For larger piles, the river becomes intermittent and the surface of the pile becomes undulating. The frequency of revolution of the river is measured as the pile grows and the results are explained with a simple scaling argument. The essential features of the system that produce the phenomena are discussed.

Four pages, five figures

References in corpus (7)

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• Creep motion in a granular pile exhibiting steady surface flow
• Tracer Dispersion in a Self-Organized Critical System
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Cited by in corpus (6)

• Revolving rivers in sandpiles: from continuous to intermittent flows
• Uphill solitary waves in granular flows
• Unsteady flows and inhomogeneous packing in damp granular heap flows
• Dynamics of fluctuation of the top location of a sandpile
• Sink versus tilt penetration into shaken dry granular matter: The role of the foundation
• Preliminary experiments demonstrating a "directed" Maxwell's granular demon