Flow rate of polygonal grains through a bottleneck: Interplay between shape and size

  • Ezequiel Goldberg Universidad Tecnol\'ogica Nacional - FRBA, UDB F\'isica, Mozart 2300, C1407IVT Buenos Aires, Argentina.
  • C. Manuel Carlevaro Instituto de F\'isica de L\'iquidos y Sistemas Biol\'ogicos (CONICET La Plata, UNLP), Calle 59 Nro 789, 1900 La Plata, Argentina. Universidad Tecnol\'ogica Nacional - FRBA, UDB F\'isica, Mozart 2300, C1407IVT Buenos Aires, Argentina.
  • Luis Ariel Pugnaloni Departamento de Ingeniería Mecánica, Facultad Regional La Plata, Universidad Tecnológica Nacional
Keywords: Granular flow, Non-circular particles

Abstract

We report two-dimensional simulations of circular and polygonal grains passing through an aperture at the bottom of a silo. The mass flow rate for regular polygons is lower than for disks\red{,} as observed by other authors. We show that both the exit velocity of the grains and the packing fraction are lower for polygons, which leads to the reduced flow rate. We point out the importance of the criteria used to define when two objects of different shape are considered to be of the same size. Depending on this criteria, the mass flow rate may vary significantly for some polygons. Moreover, the particle flow rate is non-trivially related to a combination of mass flow rate, particle shape and particle size. For some polygons, the particle flow rate may be lower or higher than that of the corresponding disks depending on the size comparison criteria.

 

Received: 18 May 2015,  Accepted: 30 October 2015; Edited by: F. Melo; Reviewed by: J.-N. Roux, Universite Parsi Est, Laboratoire Navier, Champs-sur-Marne, France; DOI: http://dx.doi.org/10.4279/PIP.070016

Cite as: E Goldberg, C M Carlevaro, L A Pugnaloni, Papers in Physics 7, 070016 (2015)

This paper, by E Goldberg, C M Carlevaro, L A Pugnaloni, is licensed under the Creative Commons Attribution License 3.0.