Název:
Turbulent Boundary Layer generated Over Two Urban Roughnesses
Autoři:
Kellnerová, Radka ; Jaňour, Zbyněk Typ dokumentu: Příspěvky z konference Konference/Akce: Experimental Fluid Mechanics 2009, Liberec (CZ), 2009-11-25 / 2009-11-27
Rok:
2009
Jazyk:
eng
Abstrakt: As a basis for PIV measurement, turbulent characteristics of a flow were investigated by LDA over two different types of urban roughness in wind-tunnel. The roughness consists from long series of street canyons with unit aspect ratio. Different shapes of roof - flat and pitched - provide a different internal boundary layer above canyons. The latter one, generated by pitched roofs, is significantly more turbulent and thus slower then above flat roofs. Momentum flux and corresponding transport exhibits the largest deviation specially at the roof level. Ventilation in the streets is therefore distinct from each other. Quadrant analysis was applied for vertical profiles and cross-sectional areas in canyons in order to detect a domination of sweep or ejection events and to find a linkage to the third moment of velocity for both cases. The overall goal of the project is to find any of coherent structure produced by the roof edge as a low momentum region or an ejection formed by hairpin.
Klíčová slova:
flat and pitched roof; quadrant analysis; street canyon; wavelet analysis Číslo projektu: CEZ:AV0Z20760514 (CEP), OC 113 Poskytovatel projektu: GA MŠk Zdrojový dokument: Experimental Fluid Mechanics 2009, ISBN 978-80-7372-538-9
Instituce: Ústav termomechaniky AV ČR
(web)
Informace o dostupnosti dokumentu:
Dokument je dostupný v příslušném ústavu Akademie věd ČR. Původní záznam: http://hdl.handle.net/11104/0178169