Simon Illingworth (Energy)
Feedback control of the cylinder wake at low Reynolds numbers is
investigated. The control arrangement consists of a velocity probe in
the cylinder's wake for sensing, together with blowing and suction on
the cylinder's surface for actuation. Using data from direct numerical
simulations as the starting point, reduced-order models of the
cylinder wake are formed at a number of Reynolds numbers. Using these
models, feedback controllers are designed using H_infinity
loop-shaping techniques. Applying these controllers in direct
numerical simulations, vortex shedding is completely suppressed up to
Reynolds numbers of 100. As well as showing the efficacy of the
feedback controllers, the presentation also addresses some of the
challenges of control.
