(490d) Continuum Modelling of the Granular Dynamics By Finite Element Method

Continuum
modelling of the granular dynamics by finite element method

Q. J. Zheng and A. B. Yu *

Laboratory for Simulation and
Modelling of Particulate Systems

Department of Chemical Engineering

Monash University

Clayton, Vic 3800, Australia

Abstract

Granular
material, as the second largest material (next to water) we humans handle, can
widely be found in nature and in industry. However, different from its
comparative phases such as gas and liquid, it still lacks a general theory to
describe its dynamics, and our understanding towards it in 1998 was still at
the level of solid-state physics in the 1930s. This talk describes an Eulerian-formulation
finite element method (FEM) approach to meet this need by focusing on a
long-standing problem in this field, i.e. the counterintuitive pressure dip phenomenon
occurring under a granular pile. Our results demonstrate that i) dynamic
history is a critical factor in the successful description of pressure dip, and
ii) the dip is complicated in nature, being sensitive to numerous variables
associated with both the piling operation and the material properties. The
proposed approach not only satisfactorily reproduces the different dip or non-dip
behaviours observed in experiments but also indicate a new direction to
describe the granular matter at the continuum/macroscopic level. This is
demonstrated in our more recent studies of granular flow in process vessels
such as hoppers and rotating drums.

Keywords: granular dynamics; continuum modelling, finite
element method