Modification of Vortex Shedding in the Synchronization Range

Abstract

One aspect of the synchronization phenomenon, which has attracted little attention so far, is the timing of vortex shedding in relation to the displacement of a bluff body. Systematic analysis of flow visualization within the synchronization range revealed that the jump in fluctuating forces had a simple fluid mechanics origin. The oscillating cylinder imposed not only its frequency to the wake behind it but also the timing of the vortex shedding. In the lower region of the synchronization range, the vortex formed on one side of the cylinder was shed when the cylinder was near to the maximum amplitude on the opposite side. This timing changed suddenly in the upper synchronization range where the vortex of the same circulation as before was shed when the cylinder reached the maximum amplitude on the same side.