Abstract
This paper presents experimental results from tests carried out in the Ifremer free surface circulation flume tank. The objective of this work is to validate the numerical work conducted under a PhD programme for the characterization of flow perturbations induced by marine current turbines. For that purpose, we used a tri-bladed horizontal axis turbine. The work is dedicated to measure the behaviour of the system and to characterize the wake emitted by the turbine. The efficiency of the turbine is quantified by the measurement of the thrust and the amount of power generated by the rotor for various inflow conditions, while the wake will be characterized by Laser Doppler Velocimetry.
Particular attention is paid to the flow characteristic effects (velocity gradient, flow orientation, etc) on the performance of a 0.70 m diameter turbine. The load predictions on the structure and the measured performance of the turbine over its working range of currents (0.6 to 1.5 m/s) and rotational speed is within 5% of TGL’s analytical model. The trials showed that this kind of turbine is sensitive to the quality of the incoming flow and a misalignment of a fixed turbine can cause significant losses. The turbulence intensity effects on turbine behaviour are also characterized in this paper.