Influence of Particulate Geometry on Permeability of Porous Materials

Abstract

The durability of porous materials -- especially when exposed to deleterious environs -- depend on their permeability. This paper takes a closer look at the governing equations of fluid flow in porous media, and examines the role of particulate geometry on liquid water permeability of porous materials. A three dimensional (3D) microstructural model is used to generate 3D microstructures of the materials. Microstructures featuring particulates with single or binary combination of geometries (i.e., spherical, cubical/cuboidal, cylindrical, and irregular), and a wide range of porosities and particulate numbers, are evaluated to elucidate their influence on permeability. A numerical model based on the lattice Boltzmann method (LBM) is used to calculate permeability of porous materials using their 3D microstructures as inputs. Results obtained from the LBM simulations show that permeability is significantly affected by geometry of the particulates - especially when the porosity is low and/or the number of particulates in the microstructure is small (e.g., < < 100). High-aspect ratio particles (e.g., cylinders) - on account of their very low sphericity and superior ability to disrupt fluid flow - consistently produce lower permeability compared to equivalent-volume particulates (e.g., spheres) that have higher sphericity. The dependency of permeability on particulate geometry decreases at higher porosities and with increasing number of particulates in the microstructure. By clarifying the dependency of permeability on particulate geometry, outcomes of this study aid in quantification of errors - in permeability estimations - that arise on account of geometric (e.g., spherical) assumptions made in various microstructural models.

Department(s)

Civil, Architectural and Environmental Engineering

Second Department

Materials Science and Engineering

Comments

Funding for this research was provided by the University of Missouri Research Board [UMRB], and the National Science Foundation [NSF, CMMI: 1661609].

Keywords and Phrases

3D microstructure modeling; Particulate geometry; Permeability; The lattice Boltzmann method

International Standard Serial Number (ISSN)

0032-5910; 1873-328X

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2019 Elsevier B.V., All rights reserved.

Publication Date

01 Mar 2019

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