Sedimentation of Compact Clusters of Uniform Spheres

Abstract

Two systems of spheres sedimenting in a viscous medium have received considerable attention: (1) initially uniform dispersions containing a large number of particles; (2) single spheres (the Stokes case). Although most of the workers in the first field have used the Stokes relationship to interpret their results there has been very little work on the sedimentation of clusters containing only a few particles such as might be considered necessary to justify the extrapolation. The work recorded here was initiated, in part, to fill this lacuna. The results obtained show that the process of sedimentation of even a few spheres is a complex process which possesses a number of interesting features.