Permeability of foam-filled granular packing: Numerical modeling

This study presents a numerical model of foam confined in granular media. It shows that, permeability decreases as the bubble-to-grain size ratio increases, due to the redistribution of liquid from the pore core to the grain-grain contacts and grain walls. It improves on previous analytical models and matches experimental data, highlighting the important role of geometrical confinement and wall plateau edges in liquid flow. The work also compares gas-liquid interfacial models and shows that a Navier slip condition - with a slip length ~2% of the bubble size - accurately accounts for the liquid permeability of bulk foam, providing an alternative to the Lemlich interfacial viscosity approach.