Flow in spiral channels of small curvature and torsion

Abstract

We compute the flow in an open helical (or spiral) channel and must, as part of the solution process, find the free surface shape which is dependent on geometrical and flow parameters. We extend work on closed spiral flows to open spiral flows, seeking for helically symmetric solutions as a first step towards solving what could be a full three-dimensional problem. For completely general channel geometries numerical methods must be used. A particular difficulty is determining the points of contact of the free surface with the channel walls. We consider channels of small curvature, small torsion and semicircular cross-section and compare with an analytic solution obtainable under these conditions. © 2001 Kluwer Academic Publishers.