SUPPRESSION OF VORTEX SHEDDING BEHIND A CIRCULAR CYLINDER BY ANOTHER CONTROL CYLINDER AT LOW REYNOLDS NUMBERS

A. Dipankar, T.K. Sengupta and S.B. Talla

Abstract

Vortex shedding behind a cylinder can be controlled by placing another control cylinder, at low Reynolds numbers, has been demonstrated experimentally in \cite{SS90}. These authors also provided preliminary numerical results, modeling the control cylinder by innovative application of boundary conditions on some selective nodes. There are no other computational and theoretical studies that has explored the physical mechanism. In the present work, using an over-set grid method, we report and verify numerically, the experimental results for flow past a pair of cylinders, as in \cite{SS90}. Apart from providing accurate solution of Navier-Stokes equation, we also employ an energy-based receptivity analysis method of \cite{SDS03} to discus some aspects of the physical mechanism behind vortex shedding and its control. These results are compared with the flow picture developed using a dynamical system approach based on proper orthogonal decomposition (POD) technique.