Pore-scale modelling of diffusion in unconsolidated porous structures
Date
2010
Authors
du Plessis E.
Woudberg S.
Prieur du Plessis J.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
A deterministic pore-scale model is used to predict the diffusivity ratio of unconsolidated porous media in which the diffusion process can be regarded as isotropic. The pore-scale model is based on a rectangular representative unit cell concept. A porosity-based weighted average of the two-dimensional and three-dimensional pore-scale models is proposed as a convenient model to predict the effective diffusion coefficient of isotropic systems. The diffusivity ratio of two-dimensionally staggered and non-staggered arrays of anisotropic solid rectangles is computed numerically and an existing weighted average model is applied to verify the numerical data. A particular case of a staggered array of solid squares, for which this weighted average model is no longer adequate, is outlined and the weighted average pore-scale model is proposed instead to predict the diffusivity ratio. The newly proposed pore-scale model and the present numerical results compare favourably with numerical data, experimental data and other predictive measures reported in the literature. © 2010 Elsevier Ltd. All rights reserved.
Description
Keywords
Anisotropic solids, Diffusion process, Diffusivity ratio, Effective diffusion coefficient, Effective diffusion coefficients, Experimental data, Isotropic systems, Mathematical modelling, Numerical data, Numerical results, Pore-scale model, Porous Media, Porous structures, Staggered arrays, Three-dimensional pores, Unconsolidated porous media, Unit cells, Weighted average models, Weighted averages, Diffusion, Granular materials, Microstructure, Numerical analysis, Porous materials, Scales (weighing instruments), Three dimensional, Mathematical models
Citation
Chemical Engineering Science
65
8
65
8