ABSTRAKT

Random migrations of non-Brownian neutrally buoyant particles in the flow of a dilute suspension in a periodic Couette cell is simulated on the basis of a dipole model. A diffusivity is due to far-field collective hydrodynamic interactions. Large-scale fluctuations of particle concentration induce fluid velocity disturbances with a lengthscale comparable to the cell size. The calculated self-diffusivity coefficient is linear in particle volume content and agrees well with the experimental data.