FLOW PAST PERIODIC ARRAYS OF SPHERES AT LOW-REYNOLDS-NUMBER

We calculate the force on a periodic array of spheres in a viscous flo w at small Reynolds number and for small volume fraction. This general izes the known results for the force on a periodic array due to Stokes flow (zero Reynolds number) and the Oseen correction to the Stokes fo rmula for the force, on a single sphere (zero volume fraction). We use a generalization of Hasimoto's approach that is based on an analysis of periodic Green's functions. We compare our results to the phenomeno logical ones of Kaneda for viscous flow past a random array of spheres .