eCite Digital Repository

Wave-turbulence decomposition methods applied to tidal energy site assessment

Citation

Perez, L and Cossu, R and Couzi, C and Penesis, I, Wave-turbulence decomposition methods applied to tidal energy site assessment, Energies, 13, (5) Article 1245. ISSN 1996-1073 (2020) [Refereed Article]


Preview
PDF
5Mb
  

Copyright Statement

Copyright 2020 by the authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/

DOI: doi:10.3390/en13051245

Abstract

High levels of turbulence have been proven to substantially increase the blade loadings on tidal turbines, outlining the need of properly characterizing turbulence parameters in tidal energy sites. The presence of long surface gravity waves may cause a significant bias on the estimation of these parameters, which requires wave-turbulence decomposition methods that are currently missing from guidelines. Here, three techniques of decomposing wave and turbulence are tested: the stopband filter (SB), moving average filter (MA), and synchrosqueezing wavelet transform (SWT). The study site, Banks Strait, Tasmania, is a 16 km wide channel that presents high potential for tidal energy generation. Wave peak periods at the study site were found to vary mostly between 7 and 12 s, with maximum exceeding 15 s. Turbulence intensities (TI), turbulent kinetic energy (TKE), and integral scales are quantified. Our results indicate differences between the estimates obtained from each method. The MA highly underestimates turbulence, resulting in TI values which were nearly 50% lower than those obtained from other decomposition methods. While TI and TKE estimated from the SB and the SWT techniques are quite similar, integral length scales are considerably underestimated by the SB. These findings reveal that the SWT is a more reliable method because of the more accurate estimates of turbulence parameters and indicate the need of establishing guidelines which address wave-turbulence decomposition in tidal stream energy site assessments. Despite having shown to be quite a versatile technique, further investigation of its applicability in data from other prospective tidal energy sites is necessary to fully assess the generality of the SWT technique.

Item Details

Item Type:Refereed Article
Keywords:tidal energy, site assessment, wave-current interaction, turbulence, integral length scales, wave-turbulence decomposition
Research Division:Engineering
Research Group:Maritime engineering
Research Field:Ocean engineering
Objective Division:Energy
Objective Group:Renewable energy
Objective Field:Tidal energy
UTAS Author:Couzi, C ( Camille Couzi)
UTAS Author:Penesis, I (Professor Irene Penesis)
ID Code:145291
Year Published:2020
Web of Science® Times Cited:6
Deposited By:NC Maritime Engineering and Hydrodynamics
Deposited On:2021-07-14
Last Modified:2021-09-21
Downloads:1 View Download Statistics

Repository Staff Only: item control page