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Bed-load transport in obliquely dune-covered riverbeds / Jan Sieben in Journal of hydraulic research, Vol. 49 N° 3 (Mai/Juin 2011) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 49 N° 3 (Mai/Juin 2011) . - pp. 317-324 Titre : Bed-load transport in obliquely dune-covered riverbeds Type de document : texte imprimé Auteurs : Jan Sieben, Auteur ; Arno M. Talmon, Auteur Année de publication : 2011 Article en page(s) : pp. 317-324 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Bed-load  transport  Dune  Fixed-bed  experiment  Helical  wake  flow  Oblique  bed  form  River 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 : In rivers, dune crest patterns are not always perpendicular to the main flow direction, because deviations up to around 20° have been observed. These can affect the direction of sediment transport, but the available predictors for models do not account for this effect. Therefore, laboratory tests on sediment transport over artificial dunes oblique to the flow direction were conducted. The largest effect is due to helical flow at the lee side of a dune and from flow near the reattachment point. These three-dimensional features are lumped into a preliminary predictor to account for the direction of bed-load in models for two-dimensional river morphology with depth-averaged flow. To include dynamic bed-form orientation, an additional model for bed-form orientation is proposed. These concepts require further validation with mobile-bed observations and subsequent tests with numerical simulations. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.566252 [article] Bed-load transport in obliquely dune-covered riverbeds [texte imprimé] / Jan Sieben, Auteur ; Arno M. Talmon, Auteur . - 2011 . - pp. 317-324. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 49 N° 3 (Mai/Juin 2011) . - pp. 317-324 Mots-clés : Bed-load  transport  Dune  Fixed-bed  experiment  Helical  wake  flow  Oblique  bed  form  River 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 : In rivers, dune crest patterns are not always perpendicular to the main flow direction, because deviations up to around 20° have been observed. These can affect the direction of sediment transport, but the available predictors for models do not account for this effect. Therefore, laboratory tests on sediment transport over artificial dunes oblique to the flow direction were conducted. The largest effect is due to helical flow at the lee side of a dune and from flow near the reattachment point. These three-dimensional features are lumped into a preliminary predictor to account for the direction of bed-load in models for two-dimensional river morphology with depth-averaged flow. To include dynamic bed-form orientation, an additional model for bed-form orientation is proposed. These concepts require further validation with mobile-bed observations and subsequent tests with numerical simulations. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.566252