Stabilization of vortices in the wake of a circular cylinder using harmonic forcing

Phys Rev E Stat Nonlin Soft Matter Phys. 2011 Jun;83(6 Pt 2):066308. doi: 10.1103/PhysRevE.83.066308. Epub 2011 Jun 10.

Abstract

We explore whether vortex flows in the wake of a fixed circular cylinder can be stabilized using harmonic forcing. We use Föppl's point vortex model augmented with a harmonic point source-sink mechanism which preserves conservation of mass and leaves the system Hamiltonian. We discover a region of Lyapunov-stable vortex motion for an appropriate selection of parameters. We identify four unique parameters that affect the stability of the vortices: the uniform flow velocity, vortex equilibrium positions, forcing amplitude, and forcing frequency. We assess the robustness of the controller using a Poincaré section.