spheres, sedimentation, sediments, equations of motion, stokes law, symmetry, particle size, numerical solution, multipoles, series expansion, viscosity, fluids
Exact periodic solutions are found for the relative motion of three spheres sedimenting in a Stokes fluid. Nearby solutions are found to be nearly periodic for a long time. Existence of the exact periodic solutions is proved using the point-particle approximation and symmetry properties of Stokes equations. Numerical simulations for finitie-sized particles are performed using a method of multipole expansions.
Sangani, Ashok S.; Caflisch, Russel E.; Lim, Chjan; and Luke, Jonathan H. C., "Periodic Solutions for Three Sedimenting Spheres" (1988). Biomedical and Chemical Engineering. Paper 16.