On a discontinuity in the laminar regime of the flow around a circular cylinder

Department of Physics and Astronomy, University of Edinburgh - Edinburgh, UK

Received: 31 October 1995
Accepted: 7 March 1996

Abstract

There has been a long-standing controversy as to the existence of a transition in the laminar regime of the flow around a circular cylinder. This was thought to be marked by a discontinuity in the Strouhal-Reynolds number relationship, but it is now known that this discontinuity disappears when the flow is two-dimensional. It has since been proposed (Green and Gerrard 1991) that there is still a transition, but one which is indicated by a discontinuity in the strength of the shed vortices. This letter presents results which show that the assumption which enabled Green and Gerrard to measure vortex strengths is invalid and that there is no discontinuity present. We conclude that no transition exists in the laminar regime.