Progressive Waves on Swirling Cavity Flow in a Circular Pipe

Abstract

The behavior of progressive waves moving through a circular pipe containing a rotating flow of water with an axial cavity is studied both theoretically and experimentally. The theoretical solution is based on an empirical relation for the rotational velocity distribution in the water along a radius between the cavity and the pipe wall, where this relation is in the form of a quadratic function fitted to experimental data. The frequencies of the progressive waves are determined experimentally from observation of the wave motion on the surface of the axial cavity. Comparison with the frequencies predicted by the theoretical solution show a satisfactory agreement. The agreement is much poorer if the rotational velocity is simply assumed to be equivalent to that induced by a potential flow vortex along the axis of the pipe.