Abstract

We investigate the two-dimensional packing of extremely prolate (aspect ratio L/D>10) granular materials, comparing experiments with Monte-Carlo simulations. In experimental piles of particles with aspect ratio 12 we find the average packing fraction to be 0.68 +/- 0.03. Both experimental and simulated piles contain a large number of horizontal particles, and particle alignment is quantified by an orientational order correlation function. In both simulation and experiment the correlation between particle orientation decays after a distance of two particle lengths. It is possible to identify voids in the pile with sizes ranging over two orders of magnitude. The experimental void distribution function is a power law with exponent -2.37 +/- 0.05. Void distributions in simulated piles do not decay as a power law, but do show a broad tail. We extend the simulation to investigate the scaling at very large aspect ratios. A geometric argument predicts the pile number density to scale as the aspect ratio to the -2 power. Simulations do indeed scale this way, but particle alignment complicates the picture, and the actual number densities are quite a bit larger than predicted.

Publication Date

2003

Comments

Also archived at: arXiv:cond-mat/0206516 v2 11 Dec 2002 ISSN:1550-2376 Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works in February 2014.

Document Type

Article

Department, Program, or Center

School of Physics and Astronomy (COS)

Campus

RIT – Main Campus

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