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(Article of periodic en Anglais - 2011)

Document title

Flow modelling in gravel-bed rivers: rethinking the bottom boundary condition

Authors(s) and Affiliation(s)

RAMESHWARAN P. (1) ; NADEN P.S. (1) ; LAWLESS M. (2) ;
(1) Centre for Ecology and Hydrology, Oxfordshire, Wallingford, ROYAUME-UNI
(2) IBA Consulting-Engineers & Scientists, North Yorkshire, Skipton, ROYAUME-UNI

Abstract

A key problem in computational fluid dynamics (CFD) modelling of gravel-bed rivers is the representation of multi-scale roughness, which spans the range from grain size, through bedforms, to channel topography. These different elements of roughness do not clearly map onto a model mesh and use of simple grain-scale roughness parameters may create numerical problems. This paper presents CFD simulations for 3 cases: a plane bed of fine gravel, a plane bed of fine gravel including large, widely-spaced pebble clusters, and a plane gravel bed with smaller, more frequent, protruding elements. Here, the spatially-averaged velocity and eddy viscosity are used to investigate the applicability of the model, compared with using the explicit high-resolution topography. The results show the ability of the model to capture the spatially-averaged flow field and, thus, illustrate its potential for representing flow processes in natural gravel-bed rivers. Finally, practical data requirements for implementing such a model for a field example are given

Source

Article of periodic

published at : Earth surface processes and landforms / ISSN 0197-9337 / CODEN ESPLDB

Editor : Wiley, Chichester - ROYAUME-UNI (1981)

Millesime : 2011, vol. 36, no10 [pp. 1350-1366]

Bibliographic references : 1 p.

Collation : 15 fig., 9 tabl.

Language

Anglais

INIST-CNRS, Cote INIST : 17355

Digital Object Identifier

Go to electronic document thanks to its DOI : doi:10.1002/esp.2158

Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI), 2012
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