Dolcetti, G. orcid.org/0000-0002-0992-0319, Horoshenkov, K.V. orcid.org/0000-0002-6188-0369, Krynkin, A. orcid.org/0000-0002-8495-691X et al. (1 more author) (2016) Frequency-wavenumber spectrum of the free surface of shallow turbulent flows over a rough boundary. Physics of Fluids, 28 (10). 105105. ISSN 1070-6631
Abstract
Data on the frequency-wavenumber spectra and dispersion relation of the dynamic water surface in an open channel flow are very scarce. In this work, new data on the frequency-wavenumber spectra were obtained in a rectangular laboratory flume with a rough bottom boundary, over a range of subcritical Froude numbers. These data were used to study the dispersion relation of the surface waves in such shallow turbulent water flows. The results show a complex pattern of surface waves, with a range of scales and velocities. When the mean surface velocity is faster than the minimum phase velocity of gravity-capillary waves, the wave pattern is dominated by stationary waves that interact with the static rough bed. There is a coherent three-dimensional pattern of radially propagating waves with the wavelength approximately equal to the wavelength of the stationary waves. Alongside these waves, there are freely propagating gravity-capillary waves that propagate mainly parallel to the mean flow, both upstream and downstream. In the flow conditions where the mean surface velocity is slower than the minimum phase velocity of gravity-capillary waves, patterns of non-dispersive waves are observed. It is suggested that these waves are forced by turbulence. The results demonstrate that the free surface carries information about the underlying turbulent flow. The knowledge obtained in this study paves the way for the development of novel airborne methods of non-invasive flow monitoring.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Civil and Structural Engineering (Sheffield) The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Mechanical Engineering (Sheffield) |
Funding Information: | Funder Grant number KNOWLEDGE TRANSFER PARTNERSHIP KTP009218 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL (EPSRC) UNSPECIFIED ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL (EPSRC) EP/N029437/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 22 Nov 2016 15:56 |
Last Modified: | 06 Nov 2018 11:03 |
Published Version: | https://doi.org/10.1063/1.4964926 |
Status: | Published |
Publisher: | AIP Publishing |
Refereed: | Yes |
Identification Number: | 10.1063/1.4964926 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:108067 |