Original title: Assessing Quality of Boundary Layer Flows With the Diagnostic Plot
Authors: Jurčáková, Klára ; Procházka, Pavel P. ; Kellnerová, Radka
Document type: Papers
Conference/Event: Topical Problems of Fluid Mechanics 2019, Prague (CZ), 20190220
Year: 2019
Language: eng
Abstract: We experimentally investigated turbulent boundary layers over 4 rough surfaces and 1 smooth surface by particle image velocimetry for a range a free stream velocities. The obtained mean velocity vertical profiles were universally scaled by roughness length z₀ and friction velocity u*, but both parameters have to be obtained from the fit of the logarithmic or composite velocity pro le to the experimental data. Diagnostic plot, which relates turbulence intensity with the mean velocity showed good collapse of different free stream velocities for each surface. It became fully universal in its modified version when the roughness function was taken into an account. We found that turbulence intensities over our surfaces are higher than any published one and that they dependent on roughness length z₀*.
Keywords: friction velocity; rough-wall; turbulence intensity; wind tunnel
Project no.: GA18-09539S (CEP)
Funding provider: GA ČR
Host item entry: Proceedings of Topical Problems of Fluid Mechanics 2019, ISBN 978-80-87012-69-7, ISSN 2336-5781

Institution: Institute of Thermomechanics AS ČR (web)
Document availability information: Fulltext is available at external website.
External URL: http://www.it.cas.cz/fm2015/im/admin/showfile/data/my/Papers/2019/15-TPFM2019.pdf
Original record: http://hdl.handle.net/11104/0298409

Permalink: http://www.nusl.cz/ntk/nusl-399117


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