Granular mixtures discharging through a silo with lateral orifice

Abstract

Here, we studied the flow dynamics of a mixture of dumbbells and disks flowing through an orifice situated on the lateral wall of a two-dimensional silo using the discrete element method. When two constituent parts of a dumbbell are simultaneously in contact with either a disk or one part of another dumbbell, it hinders the relative motion of both the particles. An increase in the fraction of dumbbells increases the number of contacts exhibiting the aforementioned mechanism, thus increasing the dynamic friction. This leads to a decrease in the flow rate with an increase in the fraction of dumbbells. To relate the flow rate with the fraction of dumbbells and the orifice width, we proposed modified Beverloo's law scaling. Moreover, we presented coarse-grained flow fields, which reveal the presence of stagnant zones that hinder the free flow of particles adjacent to them.