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Evaluation of wave-turbulence decomposition methods applied to experimental wave and grid-generated turbulence data

Citation

Perez, L and Cossu, R and Grinham, A and Penesis, I, Evaluation of wave-turbulence decomposition methods applied to experimental wave and grid-generated turbulence data, Ocean Engineering, 218 Article 108186. ISSN 0029-8018 (2020) [Refereed Article]

Copyright Statement

2020 Elsevier Ltd. All rights reserved

DOI: doi:10.1016/j.oceaneng.2020.108186

Abstract

Tidal energy turbines are significantly impacted by surface gravity waves and high turbulence levels, which lead to increased blade loads and consequent device fatigue. Accurately describing turbulence quantities is a key factor to improve numerical models and ensure the minimum necessary device longevity. The application of an appropriate wave-turbulence decomposition technique substantially improves estimates and must be debated by the tidal energy community. This work analyses two wave-turbulence decomposition techniques: i) linear wave theory and ii) Synchrosqueezing Wavelet Transform (SWT) based on physical modelling. The experiments were conducted in a towing tank and the physical model used Froude scaling to simulate wave heights and frequencies based on field measurements from a tidal energy candidate site in Australia. Turbulence was generated using a grid with 47 mm openings replicating turbulence intensities of 17%, 23% and 25%. Both decomposition techniques present limitations in wave frequencies above 0.7 Hz. Our results suggest that the SWT technique is more versatile and more efficient under various conditions. Restrictions to the linear wave theory method are discussed with regards to ADCP geometry and possible non-linearity. The variability obtained from the waveturbulence decomposition techniques emphasizes the importance of establishing guidelines for turbulence characterization in tidal energy sites.

Item Details

Item Type:Refereed Article
Keywords:grid turbulence, wave-turbulence decomposition, wave-current interaction, tidal energy site assessment
Research Division:Engineering
Research Group:Maritime engineering
Research Field:Ocean engineering
Objective Division:Energy
Objective Group:Renewable energy
Objective Field:Tidal energy
UTAS Author:Penesis, I (Professor Irene Penesis)
ID Code:145286
Year Published:2020
Web of Science® Times Cited:1
Deposited By:NC Maritime Engineering and Hydrodynamics
Deposited On:2021-07-14
Last Modified:2021-09-16
Downloads:0

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