Suppression of vortex shedding inspired by a low-dimensional model

In this paper, we show by two-dimensional numerical simulation that it is p ossible to control vortex shedding behind a circular cylinder by inserting two small vortex perturbations in the flow. The control has the effect of s uppressing vortex shedding, making the flow converge toward a stable, symme tric bubble at Reynolds number Re = 100. Similar results are obtained at hi gher Reynolds number values, e.g. Re = 1000, although the required strength of the control vortices is higher than at Re = 100. At all Reynolds number s investigated here, it is also possible to choose the control parameters i n order to alter vortex shedding by generating a reversed Karman vortex str eet. Our control technique is inspired by the linear stability analysis of a potential vortex model which we report in the present manuscript. The mod el is used here to give us insight into the control problem and the similar ity between the model and the real, viscous flow remains qualitative. (C) 2 000 Academic Press.