A Caltech Library Service

Feedback control of vortex shedding from an inclined flat plate

Joe, Won Tae and Colonius, Tim and MacMynowski, Douglas G. (2011) Feedback control of vortex shedding from an inclined flat plate. Theoretical and Computational Fluid Dynamics, 25 (1-4). pp. 221-232. ISSN 0935-4964.

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item:


Open- and closed-loop control of vortex shedding in two-dimensional flow over a flat plate at high angle of attack is numerically investigated at a Reynolds number of 300. Unsteady actuation is modeled as a body force near the leading or trailing edge and is directed either upstream or downstream. For moderate angles of attack, sinusoidal forcing at the natural shedding frequency results in phase locking, with a periodic variation of lift at the same frequency, leading to higher unsteady lift than the natural shedding. However, at sufficiently high angles of attack, a subharmonic of the forcing frequency is also excited and the average lift over the forcing period varies from cycle-to-cycle in a complex manner. It is observed that the periods with the highest averaged lift are associated with particular phase differences between the forcing and the lift, but that this highest-lift shedding cycle is not always stably maintained with open-loop forcing.We design a feedback algorithm to lock the forcing with the phase shift associated with the highest period-averaged lift. It is shown that the compensator results in a stable phase-locked limit cycle for a broader range of forcing frequencies than the open-loop control, and that it is able to stabilize otherwise unstable high-lift limit cycles that cannot be obtained with open-loop control. For example, at an angle of attack of 40◦, the feedback controller can increase the averaged magnitude of force on the plate by 76% and increase the averaged lift coefficient from 1.33 to 2.43.

Item Type:Article
Related URLs:
URLURL TypeDescription
Colonius, Tim0000-0003-0326-3909
MacMynowski, Douglas G.0000-0003-1987-9417
Additional Information:© 2010 Springer-Verlag. Received: 27 August 2009; Accepted: 6 April 2010; Published online: 10 July 2010. Communicated by T. Colonius. This work was 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:Flow control; Vortex shedding; Post stall; Feedback control; Flat plate
Issue or Number:1-4
Record Number:CaltechAUTHORS:20110613-140739970
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:23993
Deposited By: Tony Diaz
Deposited On:16 Jun 2011 17:31
Last Modified:03 Oct 2019 02:52

Repository Staff Only: item control page