Effect of an electric field on an intermittent granular flow

E. Mersch, G. Lumay, F. Boschini, and N. Vandewalle
Effect of an electric field on an intermittent granular flow
Phys. Rev. E 81, 041309, 2010
DOI: https://doi.org/10.1103/PhysRevE.81.041309

Effect of an electric field on an intermittent granular flow

 

Granular gravity driven flows of glass beads have been observed in a silo with a flat bottom.
A dc high electric field has been applied perpendicularly to the silo to tune the cohesion.

The outlet mass flow has been measured.
An image subtraction technique has been applied to visualize the flow geometry and a spatiotemporal
analysis of the flow dynamics has been performed.

The outlet mass flow is independent of voltage, but a transition from funnel flow to rathole flow is observed.

This transition is of probabilistic nature and an intermediate situation exists between the funnel and the rathole situations.

At a given voltage, two kinds of flow dynamics can occur: a continuous flow or an intermittent flow.
The electric field increases the probability to observe an intermittent flow.