Who: Dr. Miles Morgan
Affiliation: Complex Fluids Research Group, Swansea University, Wales, UK
When: April 22th, between 13:00 and 14:00 CET (Norway time)
Where: https://uio.zoom.us/j/69096081290?pwd=bg1XKTMKjweeHqxM77VmAfbOLPD0o6.1
Title: Flow regimes and instabilities in a fluid-driven granular silo
Abstract: Fluid-driven flow of granular materials can generate complex behaviour and instabilities in natural and industrial systems. Here we study a submerged silo in which imposed fluid flow drains a dense bed of sedimenting grains. As the flow rate increases, the system exhibits several regimes, including porous flow, classical silo discharge, viscous fingering, and the formation of narrow wormhole-like channels. Once formed, these channels rapidly propagate toward the outlet and act as a bypass through the surrounding packing. Balancing empirical models of surface and internal flow predicts the height at which wormholes emerge as a function of grain size and imposed flow rate, providing insight into fluid-grain interactions in geophysical and industrial systems.