TIGER Research Paper - Étude de la génération de turbulence par un fond complexe et effets potentiels sur une hydrolienne
A. Goy, P. Mercier, S. Guillou
Tidal turbines use the power of tidal streams to produce energy. Strong tidal streams are highly turbulent. The characterization of turbulence, due to interactions between the flow and the seabed, is essential for the tidal turbine design and tidal turbine farm installation. This study proposes to simulate and analyse the turbulence generated by the seabed using the Lattice Boltzmann Method. To allow for a comparison with experiments, the problem is addressed at a 1/20 scale. The seabed is modelled by canonical obstacles representative of the largest macro-roughnesses that can be observed on the real seabed of Alderney Race near La Hague Cape. This study focuses on the differences between the flow around an isolated squared base cylinder and the combination of the same cylinder with the addition of a cube upstream. The flow characteristics are studied by instantaneous and average flows, signal treatment and 3D visualisation. The comparison of signal treatment between the cylinder only and the cube upstream reveals different large eddy release frequencies, trajectories and intensities. The cube’s wake absorbs a part of the turbulence generated by the centre of the cylinder leading to a more homogeneous turbulence in the flow.