Title: Diffusion in Jammed Particle Packs

Abstract

Using random walk simulations we explore diffusive transport through monodisperse sphere packings over a range of packing fractions Φ in the vicinity of the jamming transition at Φ_c. Various diffusion properties are computed over several orders of magnitude in both time and packing pressure. Two well-separated regimes of normal “Fickian” diffusion, where the mean squared displacement is linear in time, are observed. The first corresponds to diffusion inside individual spheres, while the latter is the long-time bulk diffusion. The intermediate anomalous diffusion regime and the long-time value of the diffusion coefficient are both shown to be controlled by particle contacts, which in turn depend on proximity to Φ_c. The time required to recover normal diffusion t* scales as (Φ–Φ_c)^–0.5 and the long-time diffusivity D∞~(Φ–Φ_c)^0.5, or D_∞~1/t*. Here, it is shown that the distribution of mean first passage times associated with the escape of random walkers between neighboring particles controls both t* and D∞ in the limit Φ→Φ_c.

Authors:

Bolintineanu, Dan Stefan ^[1]; Grest, Gary S. ^[1]; Lechman, Jeremy B. ^[1]; Silbert, Leonardo E. ^[2]

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+ Show Author Affiliations

1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2. Southern Illinois Univ. Carbondale, Carbondale, IL (United States)

Publication Date:

Thu Aug 20 00:00:00 EDT 2015

Research Org.:

Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:

1512907

Alternate Identifier(s):

OSTI ID: 1212331

Report Number(s):

SAND-2015-8001J
Journal ID: ISSN 0031-9007; PRLTAO; 666888

Grant/Contract Number:  

AC04-94AL85000

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review Letters

Additional Journal Information:

Journal Volume: 115; Journal Issue: 8; Journal ID: ISSN 0031-9007

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS