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| Ikhennicheu, Maria; Germain, Gregory; Druault, Philippe; Gaurier, Benoit. |
| In high flow velocity areas like those suitable for marine energy application, bathymetry variations create strong velocity fluctuations in the water column. It is therefore essential to characterize the turbulence evolution in the wake of seabed elements which may impact the loads on tidal turbines. For that purpose, experiments are carried out in a flume tank with Re as high as achievable in Froude similitude, with bathymetry variations experimentally represented with various wall-mounted square elements of height H: a cylinder or a cube as unitary obstacles and combinations of these elements followed by an inclined floor to resemble smooth bathymetry changes. The onset flow is a simple boundary layer profile with height 1.3 H and a low turbulence... |
| Tipo: Text |
Palavras-chave: Turbulence; Experimental trials; Wall-mounted obstacles; PIV; LDV; Marine energy. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00502/61356/64997.pdf |
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| Gaurier, Benoit; Ordonez-sanchez, Stephanie; Facq, Jean-valery; Germain, Gregory; Johnstone, Cameron; Martinez, Rodrigo; Salvatore, Francesco; Santic, Ivan; Davey, Thomas; Old, Chris; Sellar, Brian. |
| This Round Robin Test program aims to establish the influence of the combined wave and current effect on the power capture and performance of a generic tidal turbine prototype. Three facilities offering similar range of experimental conditions have been selected on the basis that their dimensions along with the rotor diameter of the turbine translate into low blockage ratio conditions. The performance of the turbine shows differences between the facilities up to 25% in terms of average power coefficient, depending on the wave and current cases. To prevent the flow velocity increasing these differences, the turbine performance coefficients have been systematically normalized using a time-average disc-integrated velocity, accounting for vertical gradients... |
| Tipo: Text |
Palavras-chave: Marine energy; Wave and current interactions; Round Robin Tests; Flow measurements; Horizontal axis tidal turbine. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00635/74735/74725.pdf |
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| Mycek, Paul; Gaurier, Benoit; Germain, Gregory; Lothode, Corentin; Pinon, Gregory; Rivoalen, Elie. |
| The implantation and deployment of marine current turbine arrays depend on the understanding of their interactions. Based on a priori suggestions about the layout of marine energy converter arrays, we propose to highlight interactions effects between two horizontal axis marine current turbines, in open water. experimental trials were run in IFREMER’s wave and current flume tank in Boulogne-sur-Mer (France), on marine current turbine models. Our study focuses on setups were the second turbine is axially aligned, at different distances, in the wake of the first one. Interaction effects are pointed out both in terms of performance and wake characterisation by means of a comparison with results on a single turbine. This study shows that the downstream turbine... |
| Tipo: Text |
Palavras-chave: Marine energy; Horizontal axis marine current turbine arrays; Experimental trials; Laser Doppler velocimetry; Numerical simulation; Vortex method. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00143/25401/23557.pdf |
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| Fleming, L.e.; Mcdonough, N.; Austen, M.; Mee, L.; Moore, Michael; Hess, Philipp; Depledge, M.h.; White, M.; Philippart, Katja; Bradbrook, P.; Smalley, A.. |
| The European Marine Board recently published a position paper on linking oceans and human health as a strategic research priority for Europe. With this position paper as a reference, the March 2014 Cornwall Oceans and Human Health Workshop brought together key scientists, policy makers, funders, business, and non governmental organisations from Europe and the US to review the recent interdisciplinary and cutting edge research in oceans and human health specifically the growing evidence of the impacts of oceans and seas on human health and wellbeing (and the effects of humans on the oceans). These impacts are a complex mixture of negative influences (e.g. from climate change and extreme weather to harmful algal blooms and chemical pollution) and beneficial... |
| Tipo: Text |
Palavras-chave: Harmful algal blooms; Microbial pollution; Anthropogenic chemicals; Marine biotechnology; Climate change; Ocean acidification; Fisheries; Aquaculture; Seafood; Blue carbon; Marine energy; Blue gym; Ocean literacy; Risks; Benefits; EU Policy. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00192/30328/29066.pdf |
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| Martinez, Rodrigo; Gaurier, Benoit; Ordonez-sanchez, Stephanie; Facq, Jean-valery; Germain, Gregory; Johnstone, Cameron; Santic, Ivan; Salvatore, Francesco; Davey, Thomas; Old, Chris; Sellar, Brian G.. |
| A Round Robin Tests program is being undertaken within the EC MaRINET2 initiative. This programme studies the used facility influence can have on the performance evaluation of a horizontal axis tidal turbine prototype when it is operated under wave and current conditions. In this paper, we present the design of experiments that is used throughout the work programme and the results related to the flow characterisation obtained at the Ifremer wave and current circulating tank, the Cnr-Inm wave towing tank and the ocean research facility FloWave. These facilities have been identified to provide adequate geometric conditions to accommodate a 0.724 m diameter turbine operating at flow velocities of 0.8 and 1.0 m/s. The set-up is replicated in each of the... |
| Tipo: Text |
Palavras-chave: Marine energy; Wave and current interactions; Round Robin tests; Flow measurements; Horizontal axis tidal turbine; Uncertainty analysis. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00689/80090/83144.pdf |
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| Medina, Olmo Duran; Schmitt, Francois G.; Calif, Rudy; Germain, Gregory; Gaurier, Benoit. |
| The correlation between the flow turbulence and the performances of a marine current turbine is studied. First, the incoming flow encountered in the flume tank is characterized in the framework of fully developed turbulent cascades in the inertial range. The Reynolds number, the Kolmogorov dissipation scale and the integral scale, are estimated from flow measurements. The intermittency of the turbulence is characterized in the lognormal multifractal framework, and the influence of the turbulent flow on the turbine power is assessed. The rotor speed control unit characteristics used for the turbine regulation induces non-negligible effects on the turbine behavior under fluctuations loads. Even if the power spectrum does not reveal any scale invariance, a... |
| Tipo: Text |
Palavras-chave: Marine energy; Turbulence; Multifractal energy cascade; Intermittency; Turbine power production; High frequency data rate. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00385/49620/50134.pdf |
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| Lloyd, Catherine; Allmark, Matthew; Ordonez-sanchez, Stephanie; Martinez, Rodrigo; Johnstone, Cameron; Germain, Gregory; Gaurier, Benoit; Mason-jones, Allan; O'Doherty, Tim. |
| A comparison of a tidal turbine's performance and structural loads is conducted using lab-scale numerical models and experimental testing under multiple current-only and wave-current conditions at the IFREMER wave-current flume. Experimental testing, used to validate CFD models, was accomplished using a 0.9 m diameter, 3-bladed tidal turbine and had a blockage ratio of 8% while the turbine was submerged. Initial investigations analysed the performance and loads on the turbine under uniform and profiled current-only conditions. The presence of a profiled velocity gradient was found to have a negligible effect on the average performance characteristics; however, transient thrust, torque and out of plane bending moment loads experienced much greater... |
| Tipo: Text |
Palavras-chave: Tidal stream turbine; Wave-current interaction; Computational fluid dynamics; Regular waves; Experimental validation; Marine energy. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00678/78987/81381.pdf |
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