Optimal Control of Vortex Shedding by an Electro-Magnetic Field (Keynote)

The goal of this work is to suppress vortex shedding in the flow past a cylinder by means of a Lorentz force generated by electrodes and magnets placed on the cylinder surface alternatively. Unlike previous control schemes that were based on a crude planar structure model for the expression of the Lorentz force, our algorithm is based on an expression of the Lorentz force utilizing the electrical and magnetic potential functions, and the cylindrical structure. Asymptotic methods are used to simplify the result. The new formulation, in particular, leads to a continuous force distribution around the cylinder surface. Optimal control theory is used to derive an active feedback control algorithm aiming at determining the optimal force at each time.