Diffusion of a binary mixture in a rotating cylinder

The diffusion of a binary mixture in an axially symmetric flow in a rotating cylinder is described by the diffusion equation in which mass transport by convection, concentration and pressure diffusion is taken into account. This equation is a nonlinear partial differential equation of elliptic type. Its finite difference form, obtained by an implicit upwind difference scheme, was solved by the method of optimized successive overrelaxation. The solution was applied to the problem of separation of uranium isotopes in a fast rotating counter-current centrifuge. The concentration distribution, the separation factor and separation power are calculated for prescribed flow quantities.