Documents disponibles écrits par cet auteur

On the location in flow plan of erosion–deposition zones in sine-generated meandering streams / A. M. Ferreira Da Silva in Journal of hydraulic research, Vol. 46 extra issue (2008) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 46 extra issue (2008) . - p. 49-60 Titre : On the location in flow plan of erosion–deposition zones in sine-generated meandering streams Titre original : Sur la localisation dans le plan d'écoulement des zones d'érosion et de dépôt des courants à méandres Type de document : texte imprimé Auteurs : A. M. Ferreira Da Silva, Auteur ; T. El-Tahawy, Auteur Article en page(s) : p. 49-60 Note générale : Hydraulique Résumé en Français Langues : Anglais (eng) Mots-clés : Sine-generated  meandering  streams  Stream  curvature  Bed  deformation  Laboratory  runs  Location  of  erosion-deposition  zones  Determining  parameters 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 Résumé : This paper concerns the location in flow plan of the laterally adjacent erosion-deposition zones (“deeps” and “hills”) in sine-generated meandering streams. The aim of the paper is to gain insight into how the location of the aforementioned erosion-deposition zones is affected by stream sinuosity, as well as other geometric and flow-related parameters. For this purpose, a series of movable bed runs is carried out in a sine-generated channel having an intermediate value of the deflection angle , namely . This value extends the range of -values investigated by previous authors, who tended to focus mainly on the limiting cases of “small” and “large” values of ( and ). The runs started from a flat bed, which subsequently was allowed to develop until the equilibrium state, or a near-equilibrium state was achieved. The bed topography maps showing the bed surface at the end of the present runs were analysed together with those from previous authors’ runs. It is found that, all other conditions remaining the same, the -long erosion-deposition zone which in streams having small extends from any apex-section to the next consecutive apex-section , gradually moves upstream as increases from to – so that in the limiting case of large , this erosion-deposition zone extends from the crossover-section to the crossover-section ( and being the upstream- and downstream- crossover sections of the meander loop whose apex-section is ). For any specified , the location of the -long erosion-deposition zones appears to be affected mainly by meander wavelength relative to flow width, and perhaps also by the flow friction factor. A quantity characterizing the different distributions in flow plan of the erosion-deposition zones is introduced, and its mathematical form is investigated. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.journalhydraulicresearch.com [article] On the location in flow plan of erosion–deposition zones in sine-generated meandering streams = Sur la localisation dans le plan d'écoulement des zones d'érosion et de dépôt des courants à méandres [texte imprimé] / A. M. Ferreira Da Silva, Auteur ; T. El-Tahawy, Auteur . - p. 49-60. Hydraulique Résumé en Français Langues : Anglais (eng) in Journal of hydraulic research > Vol. 46 extra issue (2008) . - p. 49-60 Mots-clés : Sine-generated  meandering  streams  Stream  curvature  Bed  deformation  Laboratory  runs  Location  of  erosion-deposition  zones  Determining  parameters 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 Résumé : This paper concerns the location in flow plan of the laterally adjacent erosion-deposition zones (“deeps” and “hills”) in sine-generated meandering streams. The aim of the paper is to gain insight into how the location of the aforementioned erosion-deposition zones is affected by stream sinuosity, as well as other geometric and flow-related parameters. For this purpose, a series of movable bed runs is carried out in a sine-generated channel having an intermediate value of the deflection angle , namely . This value extends the range of -values investigated by previous authors, who tended to focus mainly on the limiting cases of “small” and “large” values of ( and ). The runs started from a flat bed, which subsequently was allowed to develop until the equilibrium state, or a near-equilibrium state was achieved. The bed topography maps showing the bed surface at the end of the present runs were analysed together with those from previous authors’ runs. It is found that, all other conditions remaining the same, the -long erosion-deposition zone which in streams having small extends from any apex-section to the next consecutive apex-section , gradually moves upstream as increases from to – so that in the limiting case of large , this erosion-deposition zone extends from the crossover-section to the crossover-section ( and being the upstream- and downstream- crossover sections of the meander loop whose apex-section is ). For any specified , the location of the -long erosion-deposition zones appears to be affected mainly by meander wavelength relative to flow width, and perhaps also by the flow friction factor. A quantity characterizing the different distributions in flow plan of the erosion-deposition zones is introduced, and its mathematical form is investigated. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.journalhydraulicresearch.com