dc.contributor
Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental
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Universitat Politècnica de Catalunya. LIM/UPC - Laboratori d'Enginyeria Marítima
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Universitat Politècnica de Catalunya. GITS - Modelització Integral de Conques i Transport de Sediments
dc.contributor.author
Mujal Colilles, Anna
dc.contributor.author
Christensen, Kenneth T.
dc.contributor.author
Bateman Pinzón, Allen
dc.contributor.author
Garcia, Marcelo Horacio
dc.identifier
Mujal -Colilles, A., Christensen, K. T., Bateman, A., Garcia, M. H. Coherent structures in oscillatory flows within the laminar-to-turbulent transition regime for smooth and rough walls. "Journal of hydraulic research", Abril 2016, vol. 54, núm. 5, p. 503-515.
dc.identifier
https://hdl.handle.net/2117/97719
dc.identifier
10.1080/00221686.2016.1174960
dc.description.abstract
This is an Accepted Manuscript of an article published by Taylor & Francis Group in [Journal of hydraulic research] on [2016], available online at: http://www.tandfonline.com/10.1080/00221686.2016.1174960
dc.description.abstract
We investigate coherent structures present in oscillatory boundary layers over smooth and rough beds for Reynolds numbers between 103 and 104, in the transition to turbulence regime. A two-camera 2D- particle image velocimetry (PIV) system was used to visualize coherent structures in an oscillatory-flow tunnel. The obtained results show that smooth-bed flow is populated by vortex-tube structures that are formed due to the Kelvin–Helmholtz instability. Three types of coherent structures are observed in the rough-wall experiments: vortices randomly distributed in space; turbulent bursts – spatial structures without a clear shape compared to vortices but with a longer life than the former; and shear layers of vortices originating due to flow separation from some of the grains on the bed. The reported study contributes to the description of coherent structures in oscillatory flows that are captured with the PIV technique, particularly a new structure in flows over rough beds in the transition to turbulence regime.
dc.description.abstract
Peer Reviewed
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Postprint (author's final draft)
dc.format
application/pdf
dc.relation
http://www.tandfonline.com/doi/full/10.1080/00221686.2016.1174960
dc.subject
Àrees temàtiques de la UPC::Física::Física de fluids::Flux de fluids
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Turbulence--Measurement
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Boundary layer turbulence
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coherent structures
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oscillatory flows
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particle image velocimetry (PIV)
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transition to turbulence
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Turbulència -- Mesurament
dc.title
Coherent structures in oscillatory flows within the laminar-to-turbulent transition regime for smooth and rough walls
