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| 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 |
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| Gaurier, Benoit; Druault, Ph.; Ikhennicheu, Maria; Germain, Gregory. |
| In the main tidal energy sites like Alderney Race, turbulence intensity is high and velocity fluctuations may have a significant impact on marine turbines. To understand such phenomena better, a three-bladed turbine model is positioned in the wake of a generic wall-mounted obstacle, representative of in situ bathymetric variation. From two-dimensional Particle Image Velocimetry planes, the time-averaged velocity in the wake of the obstacle is reconstructed in the three-dimensional space. The reconstruction method is based on Proper Orthogonal Decomposition and enables access to a representation of the mean flow field and the associated shear. Then, the effect of the velocity gradient is observed on the turbine blade root force, for four turbine locations... |
| Tipo: Text |
Palavras-chave: Tidal turbine; Blade force; Turbulent wake; Experimental trials; PIV; POD. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75535/76540.pdf |
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| Mycek, Paul; Gaurier, Benoit; Germain, Gregory; Pinon, Gregory; Rivoalen, Elie. |
| The future implantation of second generation marine current turbine arrays depends on the understanding of the negative interaction effects that exist between turbines in close proximity. This is especially the case when the turbines are axially aligned one behind another in the flow. In order to highlight these interaction effects, experiments were performed in a flume tank on 3-bladed 1/30th scale prototypes of horizontal axis turbines. This work focuses on the interactions between two horizontal axis marine current turbines, axially aligned with the upstream flow. Thrust and power coefficients function of the rotation speed of the downstream device are presented. Besides, the wake of each turbine is characterised so as to explain their behaviour. A... |
| Tipo: Text |
Palavras-chave: Marine current turbine; Performance; Wake; Turbulence; Array; Tidal turbine. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00175/28644/27110.pdf |
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| Boisseau, Amelie; Davies, Peter; Thiebaud, F.. |
| The development of ocean energy conversion systems places more severe requirements on materials than similar land-based structures such as wind turbines. Intervention and maintenance at sea are very costly, so for ocean energy supply to become economically viable long term durability must be guaranteed. Cyclic loading is a common feature of most energy conversion devices and composites are widely used, but few data are available concerning the fatigue behaviour in sea water of composite materials. This paper presents the results from an experimental study to fill this gap. The fatigue behavior of composite materials reinforced with different types of glass fibre is characterized in air and in sea water; the influence of testing in sea water rather than air... |
| Tipo: Text |
Palavras-chave: Composite material; Fatigue behaviour; Sea water ageing; Failure mechanism; Tidal turbine. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00134/24554/22685.pdf |
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| Boisseau, Amelie; Davies, Peter; Thiebaud, Frederic. |
| Composite material components will be an essential part of ocean energy recovery devices, and their long term durability in sea water must be guaranteed. Despite extensive experience for boat structures and wind turbines few data exist to design structures subjected to a combination of mechanical loads and sea water immersion. This paper presents the first results from an experimental study, performed jointly with fibre manufacturers, and a resin supplier, to fill this gap. The experimental study is completed by numerical modelling to simulate the coupling between water absorption and mechanical behaviour. Sea water ageing is shown to result in a drop in quasi-static mechanical properties and a change in flexural mode from compression to tension at longer... |
| Tipo: Text |
Palavras-chave: Composite material; Sea water ageing; Failure mechanism; Flexure; Tidal turbine. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00085/19578/17220.pdf |
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