Segregation in high concentration particulate flows

Particle segregation and associated problems such as inertial migration are of interest to a wide range of problems from industrial processes such as suction dredging and hydraulic conveyancing, to natural systems where sands and gravels are injected into surrounding sediments forming kilometre scale pipes and associated lateral networks. Segregation and inertial migration have long been studied in pipes but predominantly at low or very low concentrations, and typically for small particles that are in the Stokes regime. A key question is whether segregation processes vary as a function of concentration and particle size, in particularly at high concentrations (volumetric fractions of several tens of percent). This project will utilise laboratory models, and a range of visualisation / measurement techniques, including running experiments inside a Computer X-ray Tomography (CT) scanner, and using refractive index matched particles to enable internal Particle Imaging Velocimetry (PIV). In conjunction with the experimental programme, population balance modelling coupled to CFD will be utilised to examine the underlying processes of segregation within high concentration flows in conduits. Comparison can be made with the deposits of high concentration flows (likely approaching the packing limit) in natural systems where the type and magnitude of segregation can be readily observed.