Powder Technology, Vol.133, No.1-3, 91-105, 2003
Numerically simulated flow characteristics of particulate beds in oscillating sectorial containers
In this work, the well-known Cundall-Strack discrete element simulation is employed to investigate the flow characteristics of unary and binary particulate beds in oscillating sectorial containers. The simulated flow characteristics of both unary and binary granular beds in the oscillating sectorial containers have similarities with those of the particulate beds subjected to combined vertical and horizontal vibrations in that the granular bed heaps toward one of the container walls. However, heaping in an oscillating container can be either active or stagnant. Active heaping occurs in lower bounded and upper unbounded frequency ranges and is characterized by a heap that keeps shifting alternately from one radial wall to another during an oscillation cycle. In case of stagnant heaping, which occurs in an intermediate frequency range, the particulate heap becomes almost fixed and does not change its orientation with respect to the oscillating container. It is found that in the stagnant regime, there is a critical frequency at which heaping becomes symmetrical. The asymmetric heaping patterns formed in both active and stagnant regimes at frequencies below and above the critical frequency are of opposite orientations. In a binary particulate bed of initially separate layers of two different size particles, continued oscillations of the container, at frequencies in active heaping regimes, lead to good mixing of the binary set of particles. (C) 2003 Elsevier Science B.V. All rights reserved.
Keywords:discrete element simulation;particulate heaping;granular mixing;mixing rate constant;oscillating sectorial containers