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Flow structures in a shallow channel with lateral bed-roughness variation

Akutina, Y. 1; Moulin, F.; Rouzes, M.; Eiff, O. 1
1 Institut für Hydromechanik (IFH), Karlsruher Institut für Technologie (KIT)

Abstract:

Highly heterogeneous floodplains can give rise to secondary flow structures responsible for the bulk of lateral momentum exchange. Quantifying the redistribution of momentum is required to predict lateral profiles of flow velocity and the associated water level in a river. In the work herein, we focus on studying secondary flow structures and the momentum redistribution associated with a lateral bed-roughness variation in a channel with low relative submergence of the roughness elements, h/k = 3, 2 and 1.5, where h is the flow depth and k is the roughness height. A series of laboratory experiments were performed in a flume containing rows of cubes. They were arranged in two types of regular patterns, with higher and lower frontal density, and placed side by side such that the bed roughness varies in the lateral direction. The measurements were performed using stereoscopic PIV in a vertical cross plane spanning between the two roughness types. The time-averaged and turbulence statistics of the three components of the velocity field were analyzed. First, we focus on the intensity of the secondary currents. As the flow becomes shallower (lower relative submergence), the cross-stream velocity normalized by the streamwise velocity increases. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000086601
Veröffentlicht am 16.10.2018
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Hydromechanik (IFH)
KIT-Zentrum Klima und Umwelt (ZKU)
Publikationstyp Proceedingsbeitrag
Publikationsjahr 2018
Sprache Englisch
Identifikator ISSN: 2267-1242
urn:nbn:de:swb:90-866017
KITopen-ID: 1000086601
Erschienen in 9th International Conference on Fluvial Hydraulics, River Flow 2018; Lyon-Villeurbanne; France; 5 September 2018 through 8 September 2018. Ed.: A. Paquier
Verlag EDP Sciences
Seiten Art. Nr.: 02051
Serie E3S Web of Conferences ; 40
Nachgewiesen in Dimensions
Scopus
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