The dramatically increasing requirements of mobility through road-, rail- and airborne transport systems in the future necessitate non-evolutionary impro- ments of transportation systems. Without severe implications concerning the environment or restrictions concerning the performance, these requirements will only be met by a concerted action of many disciplines. It is believed that with ACTIVE FLOW CONTROL a key technology exists to supply an important block in the mosaic to be laid in the pursuit of best and sustainable solutions. Manipulation of ?uid ?ows is highly advantageous in many cases. Aerodynamic or?uid?owsaroundorinsidebodies imposedrag,liftandmoments onthebody, removeor supply energy by convection. Flow-induced noise may be produced by the interaction of a body with the surrounding air. Moreover, the interaction with the body changes the state of the ?ow drastically. A neatly aligned laminar ?ow around a wing of an aircraft giving enough lift, can become highly irregular and separatedfrom the surface,with the result of a loss of lift. For cooling of - gines of transportand other systems highly irregular turbulent ?uid ?ows across the components are needed to guarantee a large heat transfer. In future engines of airplanes complying for example with the EU Vision 2020 an increased heat transfer, on the other hand, has to be avoided by all means in some parts of the engine. Turbine stages may be exposed here to extremely hot gases, needed for highe?ciency,whichwoulddestroythe blades. Inthis application,morelaminar ?ow regimes would be advantageous yielding a poorer heat transfer. Theirregular?owinacombustore. g.
This volume contains a well balanced combination of theoretical and experimental state-of-the-art results of Active Flow Control. It combines new developments in actuator technology, sensing, robust and optimal open- and closed-loop control and model reduction for control. Numerical and experimental applications are considered from aeronautics, turbo-machinery and combustors. The contributions to this book were presented at the conference Active Flow Control 2006, held September 27-29, 2006, at the Technische Universität Berlin, Germany. The conference was organized by the Collaborative Research Center SFB 557 ‘Control of complex turbulent shear flows’, which is funded by the DFG (German Research Foundation).
