FN Archimer Export Format PT J TI On the spectral behaviour of the turbulence-driven power fluctuations of horizontal-axis turbines BT AF DESKOS, Georgios PAYNE, Gregory S. GAURIER, Benoit GRAHAM, Michael AS 1:1;2:2;3:3;4:4; FF 1:;2:;3:PDG-REM-RDT-LCSM;4:; C1 Natl Renewable Energy Lab, Natl Wind Technol Ctr, Golden, CO 80401 USA. Ecole Cent Nantes, Lab Rec Hydrodynam Energet & Environm Atmosper, 1 Rue Noe, F-44300 Nantes, France. IFREMER, Marine Struct Lab, 150 Quai Gambetta,BP 699, F-62321 Boulogne, France. Imperial Coll London, Dept Aeronaut, London SW7 2AZ, England. C2 NATL RENEWABLE ENERGY LAB, USA ECOLE CENT NANTES, FRANCE IFREMER, FRANCE IMPERIAL COLL LONDON, UK SI BOULOGNE SE PDG-REM-RDT-LCSM IN WOS Ifremer UPR copubli-france copubli-europe copubli-int-hors-europe IF 3.627 TC 18 UR https://archimer.ifremer.fr/doc/00655/76710/78175.pdf LA English DT Article DE ;flow-structure interactions AB In this article we consider the spectral behaviour of turbulence-driven power fluctuations for a single horizontal-axis turbine. To this end, a small-scale instrumented axial-flow hydrokinetic turbine model (diameter = 0.724 m) is deployed in the long water flume situated in the laboratory facilities of IFREMER in Boulogne-sur-Mer, France, and synchronous measurements of the upstream velocity and the rotor are collected for different tip-speed ratios. The study confirms previous findings suggesting that the power spectra follow the velocity spectra behaviour in the large scales region and a steeper power law slope behaviour (-11/3) over the inertial frequency sub-range. However, we show that both the amplitude of the power spectra and low-pass filtering effect over the inertial sub-range also depend on the rotor aero/hydrodynamics (e.g. dC(L)/d alpha) and the approaching flow deceleration and not solely on the rotational effects. In addition, we present a novel semi-analytical model to predict the dominant blade-passing frequency harmonics in the high-frequency regime using the rotationally sampled spectra technique. For all calculations, the distortion of incoming turbulence is taken into account. PY 2020 PD DEC SO Journal Of Fluid Mechanics SN 0022-1120 PU Cambridge Univ Press VL 904 IS A13 UT 000575471200001 DI 10.1017/jfm.2020.681 ID 76710 ER EF