This was part of Randomness in Topology and its Applications

The correspondence of max-flow to the absolute permeability of porous systems

Vanessa Robins, The Australian National University

Monday, March 20, 2023

Abstract: The absolute permeability of porous media quantifies the resistance of the material to fluid flow through it. This is an important parameter for various technological applications including ground water hydrology, hydrocarbon recovery, and microfluidics. There are scaling relationships between the geometric structure of a porous domain and its absolute permeability within a given class of structure. However, there exists no universal relationship between permeability and structure. We investigate the max-flow min-cut theorem to provide new insights into the structure of porous domains that most influence absolute permeability. The max-flow min-cut theorem states that the maximum flow through any network is exactly the sum of the edge weights that define the minimum cut. We hypothesize that the min-cut can be related to network permeability. We demonstrate that flow in porous media can be generalized and modeled as described by the max-flow min-cut theorem, which provides an approach to measure the absolute permeability of 3-dimensional digital images of porous media. The max-flow of a network is found to correspond to its absolute permeability for over four orders of magnitude and identifies structural regions that result in significant energy dissipation. The findings are beneficial for the design of porous materials, as a subroutine for digital rock studies, the simplification of large network models, and further fundamental studies on the structure and flow properties of porous media.