Jamming transition and emergence of fracturing in wet granular media

Abstract

We study fluid-induced deformation of granular media, and the fundamental role of capillarity and wettability on the emergence of fracture patterns. We develop a hydromechanical computational model, coupling a "moving capacitor" dynamic network model of two-phase flow at the pore scale with a discrete element model of grain mechanics. We simulate the slow injection of a less viscous fluid into a frictional granular pack initially saturated with a more viscous, immiscible fluid. We study the impact of wettability and initial packing density, and find four different regimes of the fluid invasion: cavity expansion and fracturing, frictional fingers, capillary invasion, and capillary compaction. We explain fracture initiation as emerging from a jamming transition, and synthesize the system's behavior in the form of a phase diagram of jamming for wet granular media.

Wettability and Lenormand's diagram

“…2020), while accounting for the wettability effects, when combined with discrete element method (known as DEM) models (Meng et al. 2020).…”

Modeling Multiphase Flow Within and Around Deformable Porous Materials: A Darcy‐Brinkman‐Biot Approach

“…Third, as currently implemented, the multiphase DBB framework only represents continuum‐level elastic or plastic solid mechanics that can be described from an Eulerian frame of reference. As such, it cannot be used to model large elastic deformations or phenomena originating from sub‐REV heterogeneities such as fluidization or granular mechanics (Meng et al., 2020), except insofar as they are captured in an averaged manner at the REV scale. Fourth, the use of the CSF as a representation of capillary forces within solid‐free regions enforces mass conservation, but it creates a diffuse fluid‐fluid interface that may generate spurious and parasitic currents.…”

Modeling Multiphase Flow Within and Around Deformable Porous Materials: A Darcy-Brinkman-Biot Approach

“…Third, as currently implemented, the multiphase DBB framework only represents continuum-level elastic or plastic solid mechanics that can be described from an Eulerian frame of reference. As such, it cannot be used to model large elastic deformations or phenomena originating from sub-REV heterogeneities such as fluidization or granular mechanics (Meng et al, 2020), except insofar as they are captured in an averaged manner at the REV scale. Fourth, the use of the CSF as a representation of capillary forces within solid-free regions enforces mass conservation, but it creates a diffuse fluid-fluid interface that may generate spurious and parasitic currents.…”