Periodic saltation under extreme tidal currents: an experimental study

Gaspard Minster 1, 2 France Floc’h Alexandre Valance Nicolas Le Dantec Amandine Nicolle 3, 2 Jean-François Filipot Benoit Zerr 1, 2
1 Lab-STICC_ENSTAB_CID_PRASYS
Lab-STICC - Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance
2 Pôle STIC_OSM
ENSTA Bretagne
Abstract : In extreme tidal environment and specifically in the Alderney race (English Channel, France), the ambition to install hydrokinetic turbines requires knowledge on the pebbles concentration in the water column. Some evidences of the presence of such coarse sediments at one meter above the bed have been found. An experimental study is realized in a free surface flume for high Stokes number. With fast camera the trajectories of hundreds of spherical particles are analyzed. This study focuses on the characterization of the critical Shields number to intermittent and saltation regime and on the coefficient of restitution between the impact and the rebound velocity . The critical Shields number is identified experimentally at 0.2. The restitution coefficient shows little dependence on the impact angle. Finally, the experimental maximum height reached by the spherical particles proves that lift and inertia forces are not negligible.
Type de document :
Communication dans un congrès
Coastal Dynamics, Jun 2017, Copenhague, Denmark. Coastal Dynamics 2017 Paper No. 058, 2017
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https://hal-ensta-bretagne.archives-ouvertes.fr/hal-01698481
Contributeur : Amandine Nicolle <>
Soumis le : jeudi 1 février 2018 - 12:52:03
Dernière modification le : mercredi 19 décembre 2018 - 15:26:08

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  • HAL Id : hal-01698481, version 1

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Gaspard Minster, France Floc’h, Alexandre Valance, Nicolas Le Dantec, Amandine Nicolle, et al.. Periodic saltation under extreme tidal currents: an experimental study . Coastal Dynamics, Jun 2017, Copenhague, Denmark. Coastal Dynamics 2017 Paper No. 058, 2017. 〈hal-01698481〉

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