Experimental study on kinetic energy conversion of horizontal axis tidal stream turbine. (November 2016)

• Record Type: Journal Article
• Authors: Seo, Jeonghwa; Lee, Seung-Jae; Choi, Woo-Sik; Park, Sung Taek; Rhee, Shin Hyung
• Is Part Of: Renewable energy. Volume 97(2016)
• Page Start: 784
• Page End: 797
• Publication Date: 2016-11
• Subjects: Tidal stream turbine -- Hydrokinetic energy -- Wake measurement -- Particle image velocimetry -- Towing tank; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2016.06.041
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: The present study aims to understand the energy conversion mechanism of a 100 kW horizontal axis tidal stream turbine by analyzing thrust, torque, and wake flow measurements. The scale ratio of the turbine model was 1/20 and model tests for power and wake measurements were conducted in a towing tank facility. Wake fields were measured by a towed underwater stereoscopic particle image velocimetry (SPIV) system. The chord-length based Reynolds number at 40% of the radius of the turbine ranged from 53, 000 to 63, 000 in the test conditions. The turbine model showed the highest power coefficient at a tip speed ratio (TSR) of 3.5, and the magnitude of power coefficient was 0.278. Three TSR conditions were selected for SPIV measurement after power measurement tests, representing heavy loading, highest efficiency, and light loading, respectively. In the wake field measurement results, conversion of kinetic energy of the turbine wake was investigated, decomposing it into effectively extracted work, loss due to the drag on the turbine system, kinetic energy of the time-mean axial flow, local flow structures, turbulence, and secondary flow loss. In high TSR conditions with a small angle of attack onto the turbine blade, the secondary flow loss was minimized. Highlights: Wake and force measurements of a HATST model were conducted in the towing tank. The measurements were characterized by a small blockage ratio and high Reynolds number. Energy conversion mechanism of a HATST was analyzed with measured data. Turbulence generation consumes only a small portion of the inflow kinetic energy.