Stokes flow down a wall into an infinite pool

Abstract

The two-dimensional flow of a thin film down a vertical or tilted plane wall into an infinite pool is studied in the Stokes approximation, the principal aim being to determine the shape of the fluid surface. Results are obtained for fluids with or without surface tension. Earlier results by Ruschak, that the surface tension gives rise to thickness variation of the film, are confirmed. For small or vanishing surface tension a dip of the pool surface is found to exist close to the wall. The case of a wall moving downwards is also considered.