Granular flows over normally vibrated inclined bases

TL;DR

This study uses discrete element simulations to analyze how external vertical vibrations of inclined bases influence granular flow profiles and mass flow rates, revealing nonlinear velocity profiles and conditions for flow rate enhancement.

Contribution

It introduces a detailed simulation analysis of vibrated inclined granular flows, showing how vibration parameters can significantly increase flow rates and alter flow profiles.

Findings

Flow velocity profiles are nonlinear under vibration.

Flow rate Q can be nearly constant with proper vibration settings.

Vibrations can increase flow rate by up to 30 times.

Abstract

We investigate granular flows over an inclined rigid base, which is vibrated externally in a direction normal to itself, through discrete element simulations. We vary the base inclination angle theta, vibration frequency f, and amplitude A to study changes in the granular flow profile and the mass flow rate Q. We find that the flow velocity profiles for the vibrated bases are nonlinear, unlike their fixed base counterparts. Our study reveals that Q may be maintained nearly constant in flows over vibrated bases utilizing appropriate combinations of theta, A, and f. At the same time, by vibrating the base at a fixed inclination, we may increase the mass flow rate by as much as 30 times the value found in flows over a stationary base. Finally, we show that Q depends upon a nondimensional number S obtained by taking the ratio of vibrational and gravitational energies.