Numerical simulation of the settling of polydisperse suspensions of spheres

The extension of Kynch's kinematical theory of ideal suspensions to polydis perse suspensions of spheres lends to a nonlinear system of conservation la ws for the volumetric concentration of each species. In this work, we consi der particle species different in sizes and densities, including the buoyan t case. We show that modern shock-capturing numerical schemes for the solut ion of systems of conservation laws can be employed as an efficient tool fo r the simulation of the settling and separation of polydisperse suspensions . This is demonstrated by comparison with published experimental and theore tical results and by simulating some hypothetical configurations. Particula r attention is focused on the emergence of rarefaction waves. (C) 2000 Else vier Science S.A, All lights reserved.