Deformable porous media

A major challenge in modelling multiphase flow in highly deformable systems is that deformation enables the emergence of completely new flow phenomena that do not have an analogue in the rigid case, the most striking of which is the ability of the non-wetting fluid to form open (solid-free) pathways and cavities. Additionally, capillary compression of the solid skeleton by an invading fluid phase can itself deform the pore structure, potentially leading to a 'self-clogging' behaviour. We have explored these phenomena by combining theoretical approaches with simple table-top experiments using packings of hydrogel beads or soft fibrillar sponges as the deformable porous medium.

Various biological and chemical processes lead to the nucleation and growth of non-wetting fluid bubbles within the pore space of a soft granular medium. The non-wetting nature of these bubbles makes it energetically costly for them to invade narrow pore throats between solid grains. If the solid skeleton is sufficiently deformable, these non-wetting bubbles can instead displace the solid to form macroscopic cavities that are much larger than the pore size. 

During my PhD, I used a combination of theoretical and experimental approaches to build towards a quantitative understanding of the parameters that control the total volume of cavities, their size distribution, and the dynamics of their formation and collapse. Understanding these processes is important for explaining the macroscopic mechanics of the composite three-phase system and its interactions with the surrounding environment.

See here for a recorded talk I gave as part of the Porous Media Tea Time Talks series, and here for our paper on the thermo-mechanics of cavity formation.