Diffusion of Brownian hard spheres in shear flow

Abstract

The tracer diffusivity of Brownian hard spheres in a shear flow is studied by numerical simulation. The trajectories are calculated by Stokesian dynamics with a diffusion tensor containing both lubrication and many hydrodynamic interactions. We study a monolayer of spheres as a function of the Peclet number $Pe = \dot \gamma {a^2}/{D_0}$. Without shear flow we recover, using only hydrodynamics, the pair distribution function of the equivalent system of kinetic hard disks. The behaviour of long time self diffusion varies drastically with the Peclet number. A qualitative interpretation of this behaviour is given in relation to the change of local structure in the suspension.