Modelling and feedback control of vortex shedding for drag reduction of a turbulent bluff body wake
File(s)IJHFF_v2.pdf (466.36 KB)
Accepted version
Author(s)
Brackston, RD
Wynn, A
Morrison, JF
Type
Journal Article
Abstract
Three-dimensional bluff body wakes are of key importance due to their relevance to the automotive industry. Such wakes have both large pressure drag and a number of coherent flow structures associated with them. Depending on the geometry, these structures may include both a bistability resulting from a spatial symmetry breaking (SB), and a quasi-periodic vortex shedding. The authors have recently shown that the bistability may be modelled by a Langevin equation and that this model enables the design of a feedback control strategy that efficiently reduces the drag through suppression of asymmetry. In this work the stochastic modelling approach is extended to the vortex shedding, capturing qualitatively both the forced and unforced behaviour. A control strategy is then presented that makes use of the frequency response of the wake, and aims to reduce the measured fluctuations associated with the vortex shedding. The strategy proves to be effective at suppressing fluctuations within specific frequency ranges but, due to amplification of disturbances at other frequencies, is unable to give drag reduction.
Date Issued
2018-04-06
Date Acceptance
2018-03-13
Citation
International Journal of Heat and Fluid Flow, 2018, 71, pp.127-136
ISSN
0142-727X
Publisher
Elsevier
Start Page
127
End Page
136
Journal / Book Title
International Journal of Heat and Fluid Flow
Volume
71
Copyright Statement
© 2018 Elsevier Inc. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Subjects
0901 Aerospace Engineering
0913 Mechanical Engineering
0915 Interdisciplinary Engineering
Mechanical Engineering & Transports
Publication Status
Published