Impact of Turbulence Generators on Turbulent Characteristics and Structures

0471312 - ÚT 2018 RIV CZ eng C - Konferenční příspěvek (zahraniční konf.)
Kellnerová, Radka - Jurčáková, Klára - Jaňour, Zbyněk
Impact of Turbulence Generators on Turbulent Characteristics and Structures.
Topical Problems of Fluid Mechanics 2017. Prague: Institute of Thermomechanics AS CR, v. v. i., 2017 - (Šimurda, D.; Bodnár, T.), s. 185-194, č. článku 024. ISBN 978-80-87012-61-1. ISSN 2336-5781.
[Topical Problems of Fluid Mechanics 2017. Prague (CZ), 15.02.2017-17.02.2017]
Grant CEP: GA ČR GA15-18964S
Institucionální podpora: RVO:61388998
Klíčová slova: turbulence generator * wind channel * vorticity * quadrant analysis
Obor OECD: Fluids and plasma physics (including surface physics)
http://www.it.cas.cz/fm2015/im/admin/showfile/data/my/Papers/2017/24-TPFM2017.pdf

The turbulent generators are routinely used to produce very turbulent flows. Special type of vertically slenderize spires are applied to enhance turbulent diffusion from the surface upwards in order to increase the boundary layer depth. This paper studies the influence of variable upstream distance of generators on formation of both vortical and non-vortical organized structures within a test section. The 2-component 2-dimensional time-resolved particle image velocimetry measurement of the flow was performed in the wind channel with very rough surface. Intermittent flow dynamics was evaluated by means of higher order moments, vorticity, quadrant and wavelet analysis. The downstream evolution of the flow suggests that equilibrium between roughness- and spires-produced turbulence was reached at the distance of 7 spires height.

Trvalý link: http://hdl.handle.net/11104/0273597