Název:
Assessing Quality of Boundary Layer Flows With the Diagnostic Plot
Autoři:
Jurčáková, Klára ; Procházka, Pavel P. ; Kellnerová, Radka Typ dokumentu: Příspěvky z konference Konference/Akce: Topical Problems of Fluid Mechanics 2019, Prague (CZ), 20190220
Rok:
2019
Jazyk:
eng
Abstrakt: 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*.
Klíčová slova:
friction velocity; rough-wall; turbulence intensity; wind tunnel Číslo projektu: GA18-09539S (CEP) Poskytovatel projektu: GA ČR Zdrojový dokument: Proceedings of Topical Problems of Fluid Mechanics 2019, ISBN 978-80-87012-69-7, ISSN 2336-5781