Nonlinear multiphase flow in hydrophobic porous media. (10th March 2022)

• Record Type: Journal Article
• Authors: Zhang, Yihuai; Bijeljic, Branko; Blunt, Martin J.
• Is Part Of: Journal of fluid mechanics. Volume 934(2022)
• Publication Date: 2022-03-10
• Subjects: multiphase flow; Fluid mechanics -- Periodicals; 532.005
• DOI: 10.1017/jfm.2021.1148
• Languages: English
• ISSNs: 0022-1120

Abstract

Abstract: Abstract : Multiphase flow in porous materials is conventionally described by an empirical extension to Darcy's law, which assumes that the pressure gradient is proportional to the flow rate. Through a series of two-phase flow experiments, we demonstrate that even when capillary forces are dominant at the pore scale, there is a nonlinear intermittent flow regime with a power-law dependence between pressure gradient and flow rate. Energy balance is used to predict accurately the start of the intermittent regime in hydrophobic porous media. The pore-scale explanation of the behaviour based on the periodic filling of critical flow pathways is confirmed through 3D micron-resolution X-ray imaging.