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Optimized Control of Vortex Shedding From an Inclined Flat Plate

Joe, Won Tae and Colonius, Tim and MacMynowski, Douglas G. (2009) Optimized Control of Vortex Shedding From an Inclined Flat Plate. In: 39th AIAA Fluid Dynamics Conference, 22–25 June 2009, San Antonio, TX.

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Optimal control theory is combined with the numerical simulation of an incompressible viscous flow to control vortex shedding in order to maximize lift. A two-dimensional flat plate model is considered at a high angle of attack and a Reynolds number of 300. Actuation is provided by unsteady mass injection near the trailing edge and is modeled by a compact body force. The adjoint of the linearized perturbed equations is solved backwards in time to obtain the gradient of the lift to changes in actuation (the jet velocity), and this information is used to iteratively improve the controls. The optimized control waveform is nearly periodic and locked to vortex shedding. We investigate how features of the optimized waveform modify the vortex shedding and lead to higher lift, and compare the results with sinusoidal open- and closed-loop control from a previous study. In the cases investigated, the optimized control is able to achieve higher average lift than the sinusoidal forcing with lower momentum coefficients. In order to obtain a practically implementable control scheme, the optimized waveform is also implemented in a simple closed-loop controller where the control signal is shifted or deformed periodically to adjust to the (instantaneous) frequency of the lift fluctuations. The feedback utilizes a narrowband filter and an Extended Kalman Filter to robustly estimate the phase of vortex shedding and achieve phase-locked, high lift flow states. Finally, the sensitivity of the flow to the phase shift and other features of the optimized waveform are examined.

Item Type:Conference or Workshop Item (Paper)
Related URLs:
URLURL TypeDescription
Colonius, Tim0000-0003-0326-3909
MacMynowski, Douglas G.0000-0003-1987-9417
Additional Information:© 2009 by Won Tae Joe, Tim Colonius, and Douglas G. MacMynowski. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. Work supported by a Multidisciplinary Research Initiative from the United States Air Force Office of Scientific Research (FA9550-05-1-0369, Program Manager: Dr. Fariba Fahroo).
Funding AgencyGrant Number
Air Force Office of Scientific Research (AFOSR)FA9550-05-1-0369
Subject Keywords:Fluid Dynamics
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Other Numbering System NameOther Numbering System ID
AIAA Paper2009-4027
Record Number:CaltechAUTHORS:20190717-102318383
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:97197
Deposited By: Melissa Ray
Deposited On:18 Jul 2019 16:42
Last Modified:16 Nov 2021 17:29

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