Rheology of confined non-Brownian suspensions

We study the rheology of confined suspensions of neutrally buoyant rigid monodisperse spheres in plane-Couette flow using Direct Numerical Simulations. We find that if the width of the channel is a (small) integer multiple of the sphere's diameter, the spheres self-organize into two-dimensional layers that slide on each other and the suspension's effective viscosity is significantly reduced. Each two-dimensional layer is found to be structurally liquid-like but their dynamics is frozen in time.Comment: Submitted to PRL. Supplemental Material added as an appendix. Includes links to youtube video

Numerical simulations of particle suspensions in conned geometries

Particle suspensions are ubiquitous in industry and natural phenomena. With the rapid development of micro-devices it becomes increasingly important to understand the behavior of owing particle suspensions in conned geometries. Here, we perform numerical simulations of particles suspended in a channel in the inertial regime, when particle and uid inertia cannot be neglected. We study the variations of the suspension's e ective viscosity and microstructure with connement