Numerical simulation of non-colloidal suspension flows in a parallel-plate geometry

The current work puts forward a numerical study of non-colloidal suspension flows in a parallel-plate geometry. The inhomogeneous Euler-Euler model applied to the continuity and momentum equations is used to solve the two-phase flow problem. The aim is at the investigation of particle motion in the suspensions flow and its consequence on the measured apparent viscosity. In contrast with prior works that dealt with neutrally buoyant flows, buoyancy is now taken into account. Good agreement was obtained between measured and computed particle distributions. Analysis of this distribution reveals that not only the particle motion but also the apparent viscosity depends on whether the lower or the upper plate is rotating. Comparisons between buoyant and non-buoyant flows were performed to understand the reasons behind the particle motion. Numerical experiments were conducted by rotating the upper or lower parallel plates and varying Reynolds number, particle volume fraction, density ratio and particle size. It can be anticipated that the particle motion in buoyant flows is mainly driven by a combination of gravity and a secondary flow perpendicular to the main circumferential flow.