Thermodynamic analysis of simple shear granular flows

Abstract

Granular flow is the collective moment of a large number of solid particles. A so-called Granular Solid Hydrodynamics (GSH) was recently proposed and expected to provide unifying descriptions of mechanical properties of granular materials. In this work, the simple shear flows with constant volume are firstly simulated with the discrete element method (DEM) where the volume fraction of solids ranges from 0.2 to 0.68. Meanwhile, the conventional kinetic theory is used for dilute systems analysis (i.e. volume fraction less than 0.6 in this study). We found the kinetic theory results about the normal stress with different volume fractions and shear rates agree well with DEM results. After improve the expression of granular temperature, GSH theory is employed to study the granular flows and the obtained results coincide with DEM and kinetic results. It is concluded that the improved GSH theory could coherently describe mechanical behavior of granular flows from quasi-static deformation until rapid flows.