Flow of Granular Materials

Flow of wet granular materials.

The transition from frictional to lubricated flows of a dense suspension of non-Brownian particles is studied. The pertinent parameter characterizing this transition is the Leighton number Le=eta(s)gamma / sigma, the ratio of lubrication to frictional forces. Le defines a critical shear rate below which no steady flow without localization exists. In the frictional regime the shear flow is local...

Stochastic flow rule for granular materials.

There have been many attempts to derive continuum models for dense granular flow, but a general theory is still lacking. Here, we start with Mohr-Coulomb plasticity for quasi-two-dimensional granular materials to calculate (average) stresses and slip planes, but we propose a "stochastic flow rule" (SFR) to replace the principle of coaxiality in classical plasticity. The SFR takes into account t...

Simulation of Gravity Flow of Granular Materials in Silos

The problem of determining the steady state flow of granular materials in silos under the action of gravity is considered. In the case of a Mohr-Coulomb material, the stress equations correspond to a system of hyperbolic conservation laws with source terms and nonlinear boundary conditions. A higher order Discontinuous Galerkin method is proposed and implemented for the numerical resolution of ...

Gravity Flow of Granular Materials in Conical Hoppers

This paper presents an approximate solution to the flow of a cohesionless granular material in a conical hopper. This is a problem which has received considerable attention in the past though much of the work was directed toward developing an empirical relation of the mass flow rate from experimental data (for example (1,211. In the early 1960's Jenike and Johanson [23] applied the basic princi...

Stability, Avalanches, and Flow in Dry and Wet Granular Materials