A fractal analytical model for Kozeny-Carman constant and permeability of roughened porous media composed of particles and converging-diverging capillaries

Seepage of particles in porous media has attracted considerable attention due to its extensive existence in nature. In this work, we have derived a novel fractal model for Kozeny-Carman (KC) constant and dimensionless permeability of roughened porous media composed of particles and converging-diverging capillaries. The model for KC constant and dimensionless permeability involves structural parameters of the media, such as porosity (phi), fractal dimensions (dT and df), relative roughness (xi), and the fluctuation amplitude (k) of capillary cross-section size. We systematically investigated the influence of the parameters above on the KC constant and the dimensionless permeability. An increase in fluctuation amplitude leads to an increase in the KC and a decrease in dimensionless permeability. In addition, the influence of the fluctuation amplitude on the KC constant and the dimensionless permeability will be more obvious with an increase in porosity. Furthermore, the effect of the fluctuation amplitude of capillary bundles on permeability satisfies the physical law. Comparisons with the experimental data in literature verifies the accuracy of the proposed fractal model. Thus, the proposed model may further reveal the physical mechanism of the fluid flow in roughened porous media, providing a better theoretical basis for various practical applications, such as petroleum engineering and fuel-cell industry.

Automated summary

This study investigates the seepage of particles in porous media and proposes a novel fractal model for the Kozeny-Carman constant and dimensionless permeability of roughened porous media. The model considers structural parameters such as porosity, fractal dimensions, relative roughness, and fluctuation amplitude of capillary cross-section size. The results show that increasing fluctuation amplitude leads to an increase in the Kozeny-Carman constant and a decrease in dimensionless permeability. Furthermore, the proposed model is validated by experimental data and can provide a theoretical basis for various practical applications in petroleum engineering and the fuel-cell industry.