Flow through an evolving porous media—compressed foam

Magnetic Resonance Imaging (MRI) techniques were applied such that they were able to provide simultaneously both 3D pore-scale velocity and microstructural data for polyurethane foam with water flowing through it. This necessitated the use of velocity gating of the relevant images in order to describe accurately the position of the solid foam walls; a pore thinning algorithm was used to differentiate individual pores within the foam pore space where minima in hydraulic radius defined pore boundaries. This methodology was then used to explore the effect of foam compression on both pore geometric characteristics and pore-scale velocity fields. Pore volumes were seen to decrease from 3.27 to 0.96 mm3 as porosity was reduced from 0.84 to 0.61 and increased flow channelling, adjacent to the containing cylinder, was observed. The velocity fields were compared with corresponding Lattice Boltzmann flow simulations with good agreement being produced.