Vortex simulation of active control strategies for transitional backward-facing step flows

In this work a vortex method is used to simulate an incompressible two-dimensional transitional flow over a backward-facing step. The simulations are validated for two different Reynolds numbers comparing to previous studies. Then, two different control strategies are implemented to modify the shedding, the recirculation zone behind the step and the transport in the channel. The first technique consists in using a pulsing inlet velocity and the second one is based on local oscillating jets implemented on the step vertical wall. The influence of these controls on several characteristic functionals related to the flow is carefully investigated. Both, open-loop and closed-loop active control approaches are performed in order to choose the most efficient control methods. (C) 2008 Elsevier Ltd. All rights reserved.