Coupling irregular particles and fluid: Complex dynamics of granular flows

Abstract

Granular materials are often encountered in nature, but the effect of their morphological properties is poorly understood when they are accompanied by fluid. This set of complexity brings the inertial, viscous, frictional, and elastic forces together whose connections remain debated. We report a novel coupled framework to study the effect of particle morphology on the dynamics of granular particles. The mechanical behavior is modeled by a new micro-mechanical model and is found to be greatly impeded by the morphology of particles. The movement difference caused by the particle shape is greatly alleviated by the presence of fluid. Our findings are demonstrated using a collapse process and we found that the dislocation is both hindered and enhanced by the viscous and lubrication effects of fluid, respectively. The results show that the effect of the fluid lubrication becomes dominant compared to the fluid viscous effect when particles become more irregular.