DEM simulation of dense granular flows in a vane shear cell: Kinematics and rheological laws

Abstract

The rheology of dense granular flows is investigated through discrete element method (DEM) simulation of a vane shear cell. From the simulation, profiles of shear stress, shear rate, and velocity are obtained, which demonstrates that the flow features in the vane shear cell are equivalent to those in the classic annular Couette cell. A novel correlation for the shear viscosity is formulated and leads to a new expression for µ KT in the kinetic theory analysis.The µ KT formulation is able to qualitatively capture the µ-I relation in the shear cell. A correlation length is added in the energy dissipation term to account for the effects of the particle motion correlation. A simplified correlation length model is derived based on DEM results and is compared with the literature. The modified granular kinetic energy equation is able to correctly predict the granular temperature profiles in the shear cell.

Power-Law Scaling in Granular Rheology across Flow Geometries

“…This ϕðμÞ relation explains how our μðI; ΘÞ relation is connected to Zhang's fluidity expression g ≡ gd=δv ¼ FðϕÞ, which has been observed to hold in previous studies [19,47,48]. First, we divide the range of I into three regimes based on the slope of the master curve in Fig.…”

Power-law scaling in granular rheology across flow geometries

“…This φ(µ) relation explains how our µ(I, Θ) relation is connected to Zhang's fluidity expression g ≡ gd/δv = F (φ), which has been observed to hold in previous studies [19,38,39]. First, we divide the range of I into three regimes based on the slope of the master curve in Fig.…”