Flow dynamics of different particle shapes in a rectangular silo.

Abstract

The present work investigates the effect of using six different particle shapes of equal volume on the discharge process of a rectangular silo with adjustable width, equipped with a flat bottom orifice opening of varying size. We find that the discharge rate decreases with the increasing aspect ratio of the particles for both lentil-shaped (oblate) and rice-shaped (prolate ellipsoidal) particles and macaroni-shaped particles show the lowest discharge rate among all the particle shapes. In addition, the silo width influences the discharge in such a way that the rates at which different particle shapes flow out from the system become more distinguishable at smaller silo widths. We observe that the velocity profile near the orifice opening becomes narrower and less sharp with increasing aspect ratio for both lentil- and rice-shaped particles. Moreover, the silo width does not have a significant influence on the velocity profile very near to the orifice, but, its influence becomes more noticeable with increasing height within the silo.