Controlling capillary fingering using pore size gradients in disordered media
Abstract
Capillary fingering is a displacement process that can occur when a non-wetting fluid displaces a wetting fluid from a homogeneous disordered porous medium. Here, we investigate how this process is influenced by a pore size gradient. Using microfluidic experiments and computational pore-network models, we show that the non-wetting fluid displacement behavior depends sensitively on the direction and the magnitude of the gradient. The fluid displacement depends on the competition between a pore size gradient and pore-scale disorder; indeed, a sufficiently large gradient can completely suppress capillary fingering. By analyzing capillary forces at the pore scale, we identify a non-dimensional parameter that describes the physics underlying these diverse flow behaviors. Our results thus expand the understanding of flow in complex porous media, and suggest a new way to control flow behavior via the introduction of pore size gradients.
Cite
@article{arxiv.1907.09073,
title = {Controlling capillary fingering using pore size gradients in disordered media},
author = {Nancy B. Lu and Christopher A. Browne and Daniel B. Amchin and Janine K. Nunes and Sujit S. Datta},
journal= {arXiv preprint arXiv:1907.09073},
year = {2022}
}
Comments
In press, Physical Review Fluids (2019)