Shear induced migration during suspension transport in regular and random porous media

Suspension transport in porous media is crucial in various industrial and natural processes, influenced by the intricate structure and interactions within the porous framework. This study investigates suspension transport in regular and random porous media using numerical simulations based on a continuum Diffusive Flux Model. The flow visualization experiments with Micro Particle Image Velocimetry were also conducted in porous micromodels. We have analysed the velocity and particle concentration fields to gain insights into the transport dynamics. In regular arrangements, specific configurations caused wavy flow paths that enhanced particle migration. The random porous media forced particles through multiple tortuous pathways, clustering near pore throats instead of migrating toward the centre, typical of channel flows. Our numerical results closely matched the experimental data. The experiments also assessed single-particle dynamics and concentrated suspension flows, demonstrating that initial particle positions significantly affect trajectory outcomes, consistent with prior Stokesian dynamics simulations. Particles near the grains experienced prolonged retention due to complex paths and strong hydrodynamic interactions. Higher particle concentrations resulted in cluster formation, leading to velocity drift, while dilute suspensions showed significant fluctuations, highlighting the concentration-dependent transport behaviour in porous media.