Permeability of porous foamy materials

TL;DR

This study investigates how open wall amount and aperture size influence the permeability of solid foams, using FEM simulations, pore-network modeling, and experimental validation to develop and confirm a predictive permeability model.

Contribution

It introduces a power-law relationship between permeability and aperture size, along with a low-cost pore-network model validated experimentally.

Findings

Permeability follows a power-law with aperture size.

Pore-network model accurately reproduces FEM results.

Experimental validation confirms the theoretical model.

Abstract

In this paper, we study the effects of both the amount of open cell walls and their aperture sizes on solid foams permeability. FEM flow simulations are performed at both pore and macroscopic scales. For foams with fully interconnected pores, we obtain a robust power-law relationship between permeability and membrane aperture size. This result owns to the local pressure drop mechanism through the membrane aperture as described by Sampson for fluid flow through a circular orifice in a thin plate. Based on this local law, pore-network simulation of simple flow is used and is shown to reproduce successfully FEM results. This low computational cost method allowed to study in detail the effects of the open wall amount on percolation, percolating porosity and permeability. A model of effective permeability is proposed and shows ability to reproduce the results of network simulations. Finally, an experimental validation of the theoretical model on well controlled solid foam is presented.