|
|
|
|
|
| Mallat, Bachar; Germain, Gregory; Billard, Jean-yves; Gaurier, Benoit. |
| The bubble sweep-down phenomenon around oceanographic research vessels generates acoustic disturbances. A specific experimental protocol in a wave and current circulating tank is used to study this phenomenon around a 1/30 scale ship model in a configuration with current, waves and ship motions. 3D visualizations of the bubble clouds and Stereo-PIV (Particle Image Velocimetry) measurements results, both obtained in the bow vicinity of the ship model, are presented in this paper. The behaviour of the breaking wave with bubble generation is studied and the spatial evolution of the bubble clouds is investigated. It is demonstrated that the bubble cloud generation is mainly conditioned by the ascending vertical velocity of the flow near the bow. It is observed... |
| Tipo: Text |
Palavras-chave: Bubble sweep-down; Breaking wave; Bow wave; Fluid-structure interaction; Flume tank. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00453/56423/58534.pdf |
| |
|
|
| Leonardi, Sophie; Rubin, Alex; Meillat, Marc; Coppin, Franck; Delpech, Jean-paul; Morandeau, Fabien; Larnaud, Pascal. |
| Ce rapport fait la synthèse des travaux réalisés en 2008 et en 2009 au cours du programme Selecmer. Celui-ci, réalisé à l'initiative des professionnels de la pêche en partenariat avec l'Ifremer, avait pour objectif de travailler à améliorer la sélectivité du chalut de fond qu'ils utilisent afin de diminuer les rejets des individus hors-tailles1, en particulier pour le merlan, tout en limitant les pertes commerciales immédiates. Une première phase a consisté à tester l'efficacité de fenêtres à mailles carrées. La deuxième phase a eu pour objectif de développer une grille sélective. Des essais en bassin et des campagnes vidéo en mer ont permis d'apporter des ajustements aux dispositifs sélectifs. L'ensemble des essais de sélectivité à bord des navires de... |
| Tipo: Text |
Palavras-chave: Professional fishermen; Square mehs; Flume tank; Selective grid; North Sea; Channel; Bottom trawl; Selectivity; Fishing; Professionnels; Mailles carrées; Campagnes à la mer; Bassin d'essais; Grille sélective; Mer du Nord; Manche; Chalut de fond; Sélectivité; Pêche. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/rapport-6776.pdf |
| |
|
| |
|
|
| Davies, Peter; Germain, Gregory; Gaurier, Benoit; Boisseau, Amelie; Perreux, Dominique. |
| The long term reliability of tidal turbines is critical if these structures are to be cost-effective. Optimised design requires a combination of material durability models and structural analyses. Composites are a natural choice for turbine blades but there are few data available to predict material behaviour under coupled environmental and cycling loading. This paper addresses this problem, by introducing a multi-level framework for turbine blade qualification. At the material scale static and cyclic tests have been performed, both in air and in seawater. The influence of ageing in seawater on fatigue performance is then quantified and much lower fatigue lives are measured after ageing. At a higher level flume tank tests have been performed on three-blade... |
| Tipo: Text |
Palavras-chave: Composite; Fatigue; Ageing; Tidal turbine; Flume tank; Finite-element model. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00079/19053/20068.pdf |
| |
|
|
| Mycek, Paul; Gaurier, Benoit; Germain, Gregory; Pinon, Gregory; Rivoalen, Elie. |
| The ambient turbulence intensity in the upstream flow plays a decisive role in the behaviour of horizontal axis marine current turbines. Experimental trials, run in the IFREMER flume tank in Boulogne-Sur-Mer (France) for two different turbulence intensity rates, namely 3% and 15%, are presented. They show, for the studied turbine configuration, that while the wake of the turbine is deeply influenced by the ambient turbulence conditions, its mean performances turn out to be slightly modified. The presented conclusions are crucial in the view of implanting second generation turbines arrays. In addition, complete and detailed data sets (wake profiles and performance graphs) are made available to the scientific community in order to encourage further... |
| Tipo: Text |
Palavras-chave: Marine current turbine; Performance; Wake; Turbulence; Experiment; Flume tank. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00175/28647/27171.pdf |
| |
|
| |
|
| |
|
|
|
