Formation and transportation of sand-heap in an inclined and vertically vibrated container

TL;DR

This study investigates how sand heaps form and move in an inclined, vibrated container, revealing the roles of gas pressure and ratchet effects in their dynamics, with experimental and theoretical insights.

Contribution

It introduces a new understanding of heap transport mechanisms in vibrated granular systems, emphasizing the influence of ambient gas cohesion and ratchet effects.

Findings

Transport velocity depends on acceleration and frequency of vibration.

Cohesion from gas pressure gradient is crucial for heap stability.

An equation governing heap velocity is proposed.

Abstract

We report the experimental findings of formation and motion of heap in granular materials in an inclined and vertically vibrated container. We show experimentally how the transport velocity of heap up container is related to the driving acceleration as well as the driving frequency of exciter. An analogous experiment was performed with a heap-shaped Plexiglas block. We propose that cohesion force resulted from pressure gradient in ambient gas plays a crucial role in enhancing and maintaining a heap, and ratchet effect causes the movement of the heap. An equation which governs the transport velocity of the heap is presented.