Skene, CS orcid.org/0000-0003-0994-2013, Yeh, C-A, Schmid, PJ et al. (1 more author) (2022) Sparsifying the resolvent forcing mode via gradient-based optimisation. Journal of Fluid Mechanics, 944. A52. ISSN 0022-1120
Abstract
We consider the use of sparsity-promoting norms in obtaining localised forcing structures from resolvent analysis. By formulating the optimal forcing problem as a Riemannian optimisation, we are able to maximise cost functionals whilst maintaining a unit-energy forcing. Taking the cost functional to be the energy norm of the driven response results in a traditional resolvent analysis and is solvable by a singular value decomposition (SVD). By modifying this cost functional with the L1 -norm, we target spatially localised structures that provide an efficient amplification in the energy of the response. We showcase this optimisation procedure on two flows: plane Poiseuille flow at Reynolds number Re=4000 , and turbulent flow past a NACA 0012 aerofoil at Re=23000 . In both cases, the optimisation yields sparse forcing modes that maintain important features of the structures arising from an SVD in order to provide a gain in energy. These results showcase the benefits of utilising a sparsity-promoting resolvent formulation to uncover sparse forcings, specifically with a view to using them as actuation locations for flow control.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This article has been published in a revised form in Journal of Fluid Mechanics [http://doi.org/10.1017/jfm.2022.519]. This version is free to view and download for private research and study only. Not for re-distribution, re-sale or use in derivative works. © The Author(s), 2022. Published by Cambridge University Press. |
Keywords: | shear-flow instability, instability control |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mathematics (Leeds) > Applied Mathematics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 13 Jul 2022 13:33 |
Last Modified: | 06 Jan 2023 01:14 |
Status: | Published |
Publisher: | Cambridge University Press |
Identification Number: | 10.1017/jfm.2022.519 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:188910 |
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