Bertrand Levaché | Searcharxiv

arXiv2017

Forced imbibition in porous media: a fourfold scenario

We establish a comprehensive description of the patterns formed when a wetting liquid displaces a viscous fluid confined in a porous medium. Building on model microfluidic experiments, we evidence four imbibition scenarios all yielding different large-scale morphologies. Combining high-resolution imaging and confocal microscopy, we show that they originate from two liquid-entrainment transitions and a Rayleigh-Plateau instability at the pore scale. Finally, we demonstrate and explain the long-time coarsening of the resulting patterns.

cond-mat.soft↗

arXiv2014

Revisiting the Saffman-Taylor experiment: imbibition patterns and liquid-entrainment transitions

We revisit the Saffman-Taylor experiment focusing on the forced-imbibition regime where the displacing fluid wets the confining walls. We demonstrate a new class of invasion patterns that do not display the canonical fingering shapes. We evidence that these unanticipated patterns stem from the entrainement of thin liquid films from the moving meniscus. We then theoretically explain how the interplay between the fluid flow at the contact line and the interface deformations results in the destabilization of liquid interfaces moving past solid surfaces. In addition, this minimal model conveys a unified framework which consistently accounts for all the liquid-entrainment scenarios that have been hitherto reported.

cond-mat.soft↗