Pore-scale modeling of fluid-particles interaction and emerging poromechanical effects

TL;DR

This paper introduces a combined DEM and pore-scale finite volume model to simulate fluid-particle interactions in granular materials, capturing poromechanical effects and phase transitions with validation against classical theories.

Contribution

It develops a novel coupled DEM-PFV model that accurately represents microscale interactions and poromechanical effects in granular materials, including phase transitions.

Findings

Model accurately simulates oedometer tests and poromechanical effects.

Demonstrates the analogy between DEM-PFV coupling and Biot's theory.

Successfully handles phase transitions in granular systems.

Abstract

A micro-hydromechanical model for granular materials is presented. It combines the discrete element method (DEM) for the modeling of the solid phase and a pore-scale finite volume (PFV) formulation for the flow of an incompressible pore fluid. The coupling equations are derived and contrasted against the equations of conventional poroelasticity. An analogy is found between the DEM-PFV coupling and Biot's theory in the limit case of incompressible phases. The simulation of an oedometer test validates the coupling scheme and demonstrates the ability of the model to capture strong poromechanical effects. A detailed analysis of microscale strain and stress confirms the analogy with poroelasticity. An immersed deposition problem is finally simulated and shows the potential of the method to handle phase transitions.