Vortex shedding mechanisms in single and dual bluff bodies

This paper presents studies of vortex shedding mechanisms in a single bluff body and two dual bluff body combination. These studies are based on video imaging of vortex shedding in open channel flow. Three thousand frames were analysed for each geometry under specified flow conditions and used to derive statistical distributions for the periods of individual cycle. For each of the combinations, the vortex mechanism for a typical half cycle is presented in six stages. The differences in mechanisms between the three geometries are highlighted and used to explain the differences in the statistical distribution of cycle periods. (C) 2002 Elsevier Science Ltd. All rights reserved.