Assessing Quality of Boundary Layer Flows With the Diagnostic Plot

0503340 - ÚT 2020 RIV CZ eng C - Konferenční příspěvek (zahraniční konf.)
Jurčáková, Klára - Procházka, Pavel P. - Kellnerová, Radka
Assessing Quality of Boundary Layer Flows With the Diagnostic Plot.
Proceedings of Topical Problems of Fluid Mechanics 2019. Praha: Institute of Thermomechanics of the Czech Academy of Sciences, 2019, s. 101-108. ISBN 978-80-87012-69-7. ISSN 2336-5781.
[Topical Problems of Fluid Mechanics 2019. Prague (CZ), 20.02.2019-22.02.2019]
Grant CEP: GA ČR(CZ) GA18-09539S
Institucionální podpora: RVO:61388998
Klíčová slova: wind tunnel * turbulence intensity * rough-wall * friction velocity
Obor OECD: Applied mechanics
http://www.it.cas.cz/fm2015/im/admin/showfile/data/my/Papers/2019/15-TPFM2019.pdf

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*.
Trvalý link: http://hdl.handle.net/11104/0298409