Hydrodynamic particle migration in a concentrated suspension undergoing flow between rotating eccentric cylinders

摘要

We report on experimental measurements and numerical predictions of shear-induced migration of particles in concentrated suspensions subjected to flow in the wide gap between a rotating inner cylinder placed eccentrically within a fixed outer cylinder (a cylindrical bearing). The suspensions consists of large, noncolloidal spherical particles suspended in a viscous Newtonian liquid. Nuclear magnetic resonance (NMR) imaging is used to measure the time evolution of concentration and velocity profiles as the flow induced particle migration from the initial, well-mixed state. A model originally proposed by Phillips et al. (1992) is generalized to two dimensions. The coupled equations of motion and particle migration are solved numerically using an explicit pseudo-transient finite volume formulation. While not all of the qualitative features observed in the experiments are reproduced by this general numerical implementation, the velocity predictions show moderately good agreement with the experimental data.