Active flow control using a reduced order model and optimum control

An approach to developing active control strategies for separated ows is presented. The methodology proposed is applied to the incompressible unsteady wake ow behind a circular cylinder at Re = 100. Control action is achieved via cylinder rotation. Low order models which are amenable to control and which incorporate the full non-linear dynamics are developed using the Proper Orthogonal Decomposition (POD) technique. These models are generated from data provided by numerical simulation. The model predictions are found to be capable of describing control-induced departures from stationary conditions, making it feasible to envisage employing them for model-based control of the vortex-shedding ow. The use of these models and the resulting optimal control results are discussed.