Permeability of a bubble assembly: From the very dry to the wet limit

TL;DR

This study measures the permeability of bubble assemblies across dry and wet regimes, demonstrating that classical models for packed spheres can be applied to deformable bubbles with mobile and non-mobile interfaces over a wide liquid fraction range.

Contribution

It extends permeability data for foam from dry to wet limits and validates classical sphere packing models for deformable bubbles with different interface mobilities.

Findings

Permeability curves connect foam and sphere suspension regimes.

Kozeny-Carman model applies to a wide range of liquid fractions.

Permeability depends on interface mobility and porosity.

Abstract

We measure the permeability of a fluidized bed of monodispersed bubbles with soap solution characteristic of mobile and non-mobile interfaces. These experimental data extend the permeability curves previously published for foam in the dry limit. In the wet limit, these data join the permeability curves of a hard sphere suspension at porosity equal to 0.4 and 0.6 in the cases of mobile and non-mobile interfaces respectively. We show that the model of permeability proposed by Kozeny and Carman and originally validated for packed beds of spheres (with porosity around 0.4) can be successfully applied with no adjustable parameters to liquid fractions from 0.001 up to 0.85 for systems made of monodisperse and deformable entities with non-mobile interfaces.