|
Titre :
|
An ordinary differential equation for velocity distribution and dip-phenomenon in open channel flows (2011)
|
|
Auteurs :
|
Absi, Rafik, Auteur
|
|
Type de document :
|
Article : texte imprimé
|
|
Dans :
|
Journal of hydraulic research (Vol. 49 N° 1, Janvier/Fevrier 2011)
|
|
Article en page(s) :
|
pp. 82-89
|
|
Note générale :
|
Hydraulique
|
|
Langues :
|
Anglais
|
|
Index. décimale :
|
627 (Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques)
|
|
Tags :
|
Dip-phenomenon Eddy viscosity Log-wake law Open channel flows Ordinary differential equation Semi-analytical solution Velocity distribution
|
|
Résumé :
|
An ordinary differential equation (ODE) for velocity distribution in open channel flows is presented based on an analysis of the Reynolds-averaged Navier-Stokes equations and a log-wake modified eddy viscosity distribution. This proposed equation allows to predict the velocity-dip-phenomenon, i.e. the maximum velocity below the free surface. Two different degrees of approximations are presented, a semi-analytical solution of the proposed ODE, i.e. the full dip-modified-log-wake law (fDMLW-law) and a simple dip-modified-log-wake law (sDMLW-law). Velocity profiles of the two laws and the numerical solution of the ODE are compared with experimental data. This study shows that the dip correction is not efficient for a small Coles' parameter, accurate predictions require larger values. The sDMLW-law shows reasonable agreement and seems to be an interesting tool of intermediate accuracy. The fDMLW-law, with a parameter for dip-correction obtained from an estimation of dip positions, provides accurate velocity profiles.
|
|
DEWEY :
|
627
|
|
ISSN :
|
0022-1686
|
|
En ligne :
|
http://www.informaworld.com/smpp/content~db=all~content=a933344782~frm=titlelink
|
