Resolving energy losses for non-uniform flows in compound channel

Autor: Proust, Sébastien, Paquier, André, Riviere, N., Bousmar, D.
Přispěvatelé: Hydrologie-Hydraulique (UR HHLY), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon, MINISTERE WALLON DE L'EQUIPEMENT ET DES TRANSPORTS CHATELET BEL, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Irstea Publications, Migration
Jazyk: angličtina
Rok vydání: 2008
Předmět:
Zdroj: 4th International Conference on Fluvial Hydraulics. River Flow 2008
4th International Conference on Fluvial Hydraulics. River Flow 2008, Sep 2008, Izmir, Turkey. pp.437-445
Popis: International audience; The aim of this paper is to evaluate the relative weights of three sources of energy loss for non-uniform flows in compound channel: (1) the bed friction; (2) the momentum transfer due to turbulent exchange between the main channel and the floodplains; and (3) the momentum transfer due to mass exchange between the subsections. Energy losses are resolved using a quasi-1D model, namely the Independent Subsections Method (ISM). The ISM computes the water level and the subsection-averaged velocities in the main channel and in the floodplains, simultaneously. This method was tested and validated against experimental measurements in three straight geometries and in eight non-prismatic geometries (skewed floodplains, diverging and converging compound channels). Using the ISM simulations of 46 flows, energy losses due to turbulent exchanges (St), to bed friction (Sf), and to mass exchanges (Sm) are estimated. The relative weights of the dissipation terms at the interfaces between the main channel and the floodplains (St and Sm) and of the mass conservation terms (denoted Ma) are then compared. The results show to what extent the mass conservation and the momentum transfer control the flow depth and the discharge in the floodplain.
Databáze: OpenAIRE