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Accueil > Actualités > Séminaires > Séminaires 2024

Mardi 18 Juin 11h00 - LEGI Salle K118

Maelys Magnier, LHyMar

Experimental study of the tidal current and the wave effects on the vortex dynamics caused by a seabed obstacle for tidal turbine development

In the current context of climate change and geopolitical crisis, it is more necessary than ever to reduce our energy consumption and produce it as cleanly and locally as possible, particularly from renewable energy sources. Among those sources, tidal currents are of high-interest thanks to their predictability. However, the unsteady and turbulent nature of tidal currents makes them complex to harness and requires detailed knowledge of the operating conditions and stresses encountered by tidal turbines. In this work, we have studied, in a controlled environment, the spatio-temporal properties of different types of flow that may be encountered in sites with high tidal energy potential : sheared, turbulent, with or without swell, independently or in interaction with each other. Based on geometric and Froude similarities with the hydrodynamic conditions of the English Channel, various grid arrangements are used to generate characteristic velocity and turbulence gradients, in the flume tank of Ifremer A bottom obstacle, representative of the Alderney Race bathymetry, is used to generate large-scale turbulent structures. Those different types of flow are first studied independently in order to characterise them thoroughly. An extensive study of the interactions between the wake generated by the bottom obstacle and the swell is then proposed. The results show that energy is exchanged at different levels, from the initialisation of the wake to its development in the water column. This study enables us to determine the swell parameters influencing the development of the vortex structures generated by the obstacle over a wide range of co-current and counter-current swells.

Contact Nathanaël Machicoane for more information or to schedule a discussion with the seminar speaker.