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arXiv · 2203.02334

Local thermodynamic description of isothermal single-phase flow in porous media

Olav Galteland·Michael T. Rauter·Mina S. Bratvold·Thuat T. Trinh·Dick Bedeaux·Signe Kjelstrup
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Abstract

Darcy's law for porous media transport is given a new local thermodynamic basis in terms of the grand potential of confined fluids. The local effective pressure gradient is determined using non-equilibrium molecular dynamics, and the hydraulic conductivity and permeability are investigated. The transport coefficients are determined for single-phase flow in face-centered cubic lattices of solid spheres. The porosity changed from that in the closest packing of spheres to near unity in a pure fluid, while the fluid mass density varied from that of a dilute gas to a dense liquid. The permeability varied between \SI{5.7e-20}{\meter^2} and \SI{5.5e-17}{\meter^2}, showing a porosity-dependent Klinkenberg effect. Both transport coefficients depended on the average fluid mass density and porosity but in different ways. These results set the stage for a non-equilibrium thermodynamic investigation of coupled transport of multi-phase fluids in complex media.

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Olav Galteland, Michael T. Rauter, Mina S. Bratvold, Thuat T. Trinh, Dick Bedeaux, Signe Kjelstrup. 2022-03-04. Local thermodynamic description of isothermal single-phase flow in porous media. https://arxiv.org/abs/2203.02334

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