Details

Autor(en) / Beteiligte

• Xu, Wenxiang
• Zhang, Kaixing
• Zhang, Yufeng
• Jiang, Jinyang

Titel

Packing Fraction, Tortuosity, and Permeability of Granular‐Porous Media With Densely Packed Spheroidal Particles: Monodisperse and Polydisperse Systems

Ist Teil von

• Water resources research, 2022-02, Vol.58 (2), p.n/a

Ort / Verlag

Washington: Blackwell Publishing Ltd

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Wiley Blackwell Single Titles

Beschreibungen/Notizen

• The geometrical and topological configurations of particles have great influences on their surrounding pore tortuosity and the permeability of granular‐porous media. In this work, we develop a relaxation iteration scheme to create random dense packings of different anisotropic‐shaped spheroidal particles with monodispersity and polydispersity in sizes, which manifest the effects of particle shape, fineness, and size distribution on the random packing fraction of particles. Subsequently, we propose a direction‐guided rapidly exploring random tree (DGRRT) algorithm to probe the geometrical tortuosity of complex pore space interstitial to spheroidal particles. A non‐linear pore tortuosity prediction model that relies on the specific surface area and packing fraction of particles, is developed to suit for polydisperse and monodisperse spheroidal particle systems. We further investigate the permeability of granular‐porous media through the lattice Boltzmann method (LBM) of fluid flow. These proposed methods can accurately predict the tortuosity and permeability by comparing against available experimental, theoretical, and numerical results reported in literature. Moreover, the effects of particle packing fraction (i.e., porosity), shape, fineness, and size distribution on the pore tortuosity and permeability of granular‐porous media are evaluated. The results reveal that these microstructural configurations have important influences on the permeability and tortuosity. Our results give an intrinsic interplay between the geometrical tortuosity and permeability of monodisperse and polydisperse particle systems, which have implications for a broad range of scientific disciplines, including the properties of rocks, sandstones and soils, and the design of ultra‐high performance concrete. Plain Language Summary Random packing of spheroidal particles arises in a variety of problems, involving precipitation of salt crystals during CO2 sequestration in rock and intrusion of fresh water in aquifers by saline water. The packing properties are also crucial to explore the effects of particle configurations on the pore tortuosity interstitial to particles and the permeability of porous media. This contribution develops a relaxation iteration scheme to realize random dense packings of monodisperse and polydisperse spheroidal particles. The maximum random packing fraction approaches 0.844 that is the highest packing fraction of spheroidal particles yet simulated. Subsequently, a direction‐guided rapidly exploring random tree algorithm is proposed to obtain the pore tortuosity. A non‐linear tortuosity model that relies on the specific surface area and packing fraction of particles, is derived. Moreover, the lattice Boltzmann method is presented to explore the effective permeability of spheroidal particle packings. The results elucidated that the particle shape, packing fraction, size distribution, and non‐uniformity coefficient have significant effects on the permeability of systems studied. Our numerical models and findings can provide insights on designing the geometrical configurations of particles for regulating their surrounding pore tortuosity, and further for optimizing the physical and mechanical properties of porous media in practice. Key Points Relaxation iteration scheme generates random dense packings of spheroids with monodispersity and polydispersity in sizes An accurate and efficient direction‐guided rapidly exploring random tree algorithm and a non‐linear model are developed for the pore tortuosity around mono‐/poly‐disperse spheroids Effects of particle shape, fineness, and particle size distribution on the particle packing fraction, pore tortuosity and permeability are quantitatively evaluated