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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 facilities with exemption of the amount of flow measuring instruments. Intrinsic differences in creating wave and currents between facilities are found. Flow velocities are up to 10% higher than the nominal values and wave amplitudes higher than the target values by up to a factor of 2. These discrepancies are related to the flow and wave generation methods used at each facility. When the flow velocity is measured besides the rotor, the velocity presents an increase of 8% compared to the upstream measurements.
Rodrigo Martinez; Benoît Gaurier; Stephanie Ordonez-Sanchez; Jean-Valéry Facq; Gregory Germain; Cameron Johnstone; Ivan Santic; Francesco Salvatore; Thomas Davey; Chris Old; Brian Sellar. Tidal Energy Round Robin Tests: A Comparison of Flow Measurements and Turbine Loading. Journal of Marine Science and Engineering 2021, 9, 425 .
AMA StyleRodrigo Martinez, Benoît Gaurier, Stephanie Ordonez-Sanchez, Jean-Valéry Facq, Gregory Germain, Cameron Johnstone, Ivan Santic, Francesco Salvatore, Thomas Davey, Chris Old, Brian Sellar. Tidal Energy Round Robin Tests: A Comparison of Flow Measurements and Turbine Loading. Journal of Marine Science and Engineering. 2021; 9 (4):425.
Chicago/Turabian StyleRodrigo Martinez; Benoît Gaurier; Stephanie Ordonez-Sanchez; Jean-Valéry Facq; Gregory Germain; Cameron Johnstone; Ivan Santic; Francesco Salvatore; Thomas Davey; Chris Old; Brian Sellar. 2021. "Tidal Energy Round Robin Tests: A Comparison of Flow Measurements and Turbine Loading." Journal of Marine Science and Engineering 9, no. 4: 425.
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 over the turbine swept area. Differences linked to blockage effects and turbulence characteristics between facilities are both responsible for 5 to 10% of the power coefficient gaps. The intrinsic differences between the tanks play a significant role as well. A first attempt is given to show how the wave-current interaction effects can be responsible for differences in the turbine performance. In these tanks, the simultaneous generation of wave and current is a key part often producing disruptions in both of these flow characteristics.
Benoît Gaurier; Stephanie Ordonez-Sanchez; Jean-Valéry Facq; Grégory Germain; Cameron Johnstone; Rodrigo Martinez; Francesco Salvatore; Ivan Santic; Thomas Davey; Chris Old; Brian Sellar. MaRINET2 Tidal Energy Round Robin Tests—Performance Comparison of a Horizontal Axis Turbine Subjected to Combined Wave and Current Conditions. Journal of Marine Science and Engineering 2020, 8, 463 .
AMA StyleBenoît Gaurier, Stephanie Ordonez-Sanchez, Jean-Valéry Facq, Grégory Germain, Cameron Johnstone, Rodrigo Martinez, Francesco Salvatore, Ivan Santic, Thomas Davey, Chris Old, Brian Sellar. MaRINET2 Tidal Energy Round Robin Tests—Performance Comparison of a Horizontal Axis Turbine Subjected to Combined Wave and Current Conditions. Journal of Marine Science and Engineering. 2020; 8 (6):463.
Chicago/Turabian StyleBenoît Gaurier; Stephanie Ordonez-Sanchez; Jean-Valéry Facq; Grégory Germain; Cameron Johnstone; Rodrigo Martinez; Francesco Salvatore; Ivan Santic; Thomas Davey; Chris Old; Brian Sellar. 2020. "MaRINET2 Tidal Energy Round Robin Tests—Performance Comparison of a Horizontal Axis Turbine Subjected to Combined Wave and Current Conditions." Journal of Marine Science and Engineering 8, no. 6: 463.
The flow developed on a tidal site can be characterized by combinations of turbulence, shear flows, and waves. Horizontal-axis tidal turbines are therefore subjected to dynamic loadings that may compromise the working life of the rotor and drive train components. To this end, a series of experiments were carried out using a 0.9 m horizontal-axis tidal turbine in a tow tank facility. The experiments included two types of regular waveforms, one of them simulating an extreme wave case, the other simulating a more moderate wave case. The second regular wave was designed to match the peak period and significant wave height of an irregular wave which was also tested. Measurements of torque, thrust, and blade-bending moments were taken during the testing campaign. Speed and torque control strategies were implemented for a range of operational points to investigate the influence that a control mode had in the performance of a tidal stream turbine. The results showed similar average power and thrust values were not affected by the control strategy, nor the influence of either the regular or irregular wave cases. However, it was observed that using torque control resulted in an increase of thrust and blade root bending moment fluctuations per wave period. The increase in fluctuations was in the order of 40% when compared to the speed control cases.
Stephanie Ordonez-Sanchez; Matthew Allmark; Kate Porter; Robert Ellis; Catherine Lloyd; Ivan Santic; Tim O’Doherty; Cameron Johnstone. Analysis of a Horizontal-Axis Tidal Turbine Performance in the Presence of Regular and Irregular Waves Using Two Control Strategies. Energies 2019, 12, 367 .
AMA StyleStephanie Ordonez-Sanchez, Matthew Allmark, Kate Porter, Robert Ellis, Catherine Lloyd, Ivan Santic, Tim O’Doherty, Cameron Johnstone. Analysis of a Horizontal-Axis Tidal Turbine Performance in the Presence of Regular and Irregular Waves Using Two Control Strategies. Energies. 2019; 12 (3):367.
Chicago/Turabian StyleStephanie Ordonez-Sanchez; Matthew Allmark; Kate Porter; Robert Ellis; Catherine Lloyd; Ivan Santic; Tim O’Doherty; Cameron Johnstone. 2019. "Analysis of a Horizontal-Axis Tidal Turbine Performance in the Presence of Regular and Irregular Waves Using Two Control Strategies." Energies 12, no. 3: 367.