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An example of active circulation control of the unsteady separated flow past a semi-infinite plate

Published online by Cambridge University Press:  26 April 2006

L. Cortelezzi
Affiliation:
Department of Engineering Science, California Institute of Technology, Pasadena, CA 91125, USA Present address: Department of Mathematics, University of California, Los Angeles. CA 90024-1555 USA.
A. Leonard
Affiliation:
Graduate Aeronautical Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
J. C. Doyle
Affiliation:
Department of Electrical Engineering, California Institute of Technology, Pasadena, CA 91125, USA

Abstract

Active circulation control of the two-dimensional unsteady separated flow past a semiinfinite plate with transverse motion is considered. The rolling-up of the separated shear layer is modelled by a point vortex whose time-dependent circulation is predicted by an unsteady Kutta condition. A suitable vortex shedding mechanism introduced. A control strategy able to maintain constant circulation when a vortex is present is derived. An exact solution for the nonlinear controller is then obtained. Dynamical systems analysis is used to explore the performance of the controlled system. The control strategy is applied to a class of flows and the results are discussed. A procedure to determine the position and the circulation of the vortex, knowing the velocity signature on the plate, is derived. Finally, a physical explanation of the control mechanism is presented.

Type
Research Article
Copyright
© 1994 Cambridge University Press

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