Turbulent flows in straight compound open-channel with a transverse embankment on the floodplain
Ecoulements turbulents en lit composé droit avec une digue transversale sur la plaine d'inondation
Peltier, Y. ; Proust, S. ; Rivière, N. ; Paquier, A. ; Shiono, K.
Type de document
Article de revue scientifique à comité de lecture
Affiliation de l'auteur
IRSTEA LYON UR HHLY FRA ; IRSTEA LYON UR HHLY FRA ; UNIVERSITE DE LYON UMR 5509 LMFA LABORATOIRE DE MECANIQUE DES FLUIDES ET D'ACOUSTIQUE LYON FRA ; IRSTEA LYON UR HHLY FRA ; LOUGHBOROUGH UNIVERSITY GBR
Résumé / Abstract
The present study deals with turbulent flows in an asymmetrical compound channel with an embankment set on the floodplain, perpendicularly to the longitudinal direction. The main purpose of this study was to assess how a rapidly varied flow affects interaction between the floodplain flow and the main channel flow. In addition to rapid changes in the water level and velocity across the compound channel that have a great influence on the boundary shear stress distribution, the embankment, through two recirculation zones developing upstream and downstream, is also responsible for strong lateral mass exchange between the main channel and the floodplains (channel sub-sections). The lateral velocity can indeed reach 50% of the longitudinal velocity, which modifies the characteristics of the mixing layer developing between the channel sub-sections. Depth-averaged Reynolds shear stresses five times greater than those measured for reference.
Journal of Hydraulic Research, vol. 51, num. 4, p. 446 - 458