Three-Dimensional Monte Carlo Simulations of Density Relaxation

Abstract

The packing efficiency of granular materials is an important consideration in a variety of industrial settings. Here, the density relaxation problem is studied using three dimensional Monte Carlo simulations, which model the effect of regular taps applied to vessel having a planar floor filled with hard spheres. Results show that the equilibrium bulk solids fraction depends strongly upon the intensity of the taps, with relatively lower intensity taps producing more dense systems. A broad range of solids fractions are generated, starting from a loose configuration, rather like a ‘poured’ assembly, to a relatively dense structure having local crystalline order. Reasonably good agreement of the computed coordination number with experiments in the literature is found. Results show an enhanced tap-induced ordering effect of the floor on the local microstructure, which is reflected in the radial distribution function. For energetic taps, the solids fraction evolution fit well to a hyperbolic tangent model, while results at low intensity taps are described by an inverse log law.

Keywords

• density relaxation
• monte carlo simulation
• solids fraction evolution
• vibrated bulk solids