[article]
Titre : |
Scour upstream of a circular orifice under constant head |
Type de document : |
texte imprimé |
Auteurs : |
David N. Powell, Auteur ; Abdul A. Khan, Auteur |
Année de publication : |
2012 |
Article en page(s) : |
pp. 28-34 |
Note générale : |
Hydraulique |
Langues : |
Anglais (eng) |
Mots-clés : |
Circular orifice Local scour Scour mechanism shape Vortex action |
Résumé : |
The transport mechanism as well as the extent and the shape of the scour upstream of a circular orifice is investigated under steady flow conditions for different sediment sizes and heads on the orifice. The main mechanism of sediment transport is found to be vortex-related, appearing randomly within the scour hole. The scour length, maximum scour width, and maximum scour depth are evaluated for various sediment sizes and under different heads on the orifice. The non-dimensional scour depth profiles along the orifice centreline are found to be similar. The non-dimensional scour depth profiles across the width of the scour hole at various locations upstream of the orifice are found to be similar as well. The flow characteristics related to the scaled centreline longitudinal velocity and the scaled position of the maximum longitudinal velocity are found to approach those for the unbounded orifice at the equilibrium scour condition. |
DEWEY : |
627 |
ISSN : |
0022-1686 |
En ligne : |
http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.637821 |
in Journal of hydraulic research > Vol. 50 N° 1 (Janvier/Février 2012) . - pp. 28-34
[article] Scour upstream of a circular orifice under constant head [texte imprimé] / David N. Powell, Auteur ; Abdul A. Khan, Auteur . - 2012 . - pp. 28-34. Hydraulique Langues : Anglais ( eng) in Journal of hydraulic research > Vol. 50 N° 1 (Janvier/Février 2012) . - pp. 28-34
Mots-clés : |
Circular orifice Local scour Scour mechanism shape Vortex action |
Résumé : |
The transport mechanism as well as the extent and the shape of the scour upstream of a circular orifice is investigated under steady flow conditions for different sediment sizes and heads on the orifice. The main mechanism of sediment transport is found to be vortex-related, appearing randomly within the scour hole. The scour length, maximum scour width, and maximum scour depth are evaluated for various sediment sizes and under different heads on the orifice. The non-dimensional scour depth profiles along the orifice centreline are found to be similar. The non-dimensional scour depth profiles across the width of the scour hole at various locations upstream of the orifice are found to be similar as well. The flow characteristics related to the scaled centreline longitudinal velocity and the scaled position of the maximum longitudinal velocity are found to approach those for the unbounded orifice at the equilibrium scour condition. |
DEWEY : |
627 |
ISSN : |
0022-1686 |
En ligne : |
http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.637821 |
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