Effects of grain's shape- and size-polydispersities, orientation, and area fraction on tortuosity and permeability of 2D granular media--颗粒学报PARTICUOLOGY

Cao, K., Chen, H., Khan, M. I., Li, M., & Liu, L. (2024). Effects of grain's shape- and size-polydispersities, orientation, and area fraction on tortuosity and permeability of 2D granular media. Particuology, 90, 535-557. https://doi.org/10.1016/j.partic.2024.01.016

Effects of grain's shape- and size-polydispersities, orientation, and area fraction on tortuosity and permeability of 2D granular media

Ke Cao ^a, Huisu Chen ^a *, Mohammad Iqbal Khan ^b *, Mingqi Li ^c *, Lin Liu ^d *

a Jiangsu Key Laboratory of Construction Materials, School of Materials Science and Engineering, Southeast University, Nanjing 211189, China
b Department of Civil Engineering, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
c School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, China
d College of Civil and Transportation Engineering, Hohai University, Nanjing, 210098, China

10.1016/j.partic.2024.01.016

Volume 90, July 2024, Pages 535-557

Received 22 November 2023, Revised 23 January 2024, Accepted 23 January 2024, Available online 6 February 2024, Version of Record 26 February 2024.

E-mail: chenhs@seu.edu.cn; miqbal@ksu.edu.sa; limingqi@hebut.edu.cn; liulin@hhu.edu.cn

Highlights

• 2D geometric tortuosities of various non-circular granular medias were derived.

• Effects of shape, orientation, and concavity on tortuosity were quantified.

• Shape and size polydispersities were included in modified Kozeny-Carman model.

• Grain composition's impact on 2D permeability was characterized.

Abstract

The microstructure of granular media, including grain's shape- and size-polydispersities, orientation, and area fraction can potentially affect its permeability. However, few studies consider the coupling effects of these features. This work employs geometrical probability and stereology to establish quantitative relationships between the above microstructural features and the geometric tortuosity of the two-dimensional granular media containing superellipse, superoval, and polygon grains. Then the lattice Boltzmann method (LBM) is used to determine the permeabilities of these granular media. By combining the tortuosity model and the LBM-derived permeabilities, modified K–C equations are formulated to predict the permeability and the shape factor, considering the grain's shape- and size-polydispersities, orientation, and area fraction. The reliability of these methods can be verified by comparing them with both our simulations and available experimental, theoretical, and numerical data reported in the literature. The findings implicate that the tortuosity and permeability of the granular media are strongly correlated with the grain's shape, orientation, and area fraction but unaffected by the size polydispersity and spatial arrangement of grains. Only circularity is not enough to derive a unified formula for considering the impact of grain shape on tortuosity and permeability, other shape parameters need to be explored in the future.

Graphical abstract

Keywords

Geometric tortuosity; Konzey-Carman equation; Shape and size ploydispersities; Grain orientation; Lattice Boltzmann method; Granular media

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