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Investigations on 3D effects and correlation between wave height and lip submergence of an offshore stationary OWC wave energy converter


Elhanafi, A and MacFarlane, G and Fleming, A and Leong, Z, Investigations on 3D effects and correlation between wave height and lip submergence of an offshore stationary OWC wave energy converter, Applied Ocean Research, 64 pp. 203-216. ISSN 0141-1187 (2017) [Refereed Article]

Copyright Statement

Copyright 2017 Elsevier Ltd.

DOI: doi:10.1016/j.apor.2017.03.002


Understanding the hydrodynamic interactions between ocean waves and the oscillating water column (OWC) wave energy converter is crucial for improving the device performance. Most previous relevant studies have focused on testing onshore and offshore OWCs using 2D models and wave flumes. Conversely, this paper provides experimental results for a 3D offshore stationary OWC device subjected to regular waves of different heights and periods under a constant power take–off (PTO) damping simulated by an orifice plate of fixed diameter. In addition, a 3D computational fluid dynamics (CFD) model based on the RANS equations and volume of fluid (VOF) surface capturing scheme was developed and validated against the experimental data. Following the validation stage, an extensive campaign of computational tests was performed to (1) discover the impact of testing such an offshore OWC in a 2D domain or a wave flume on device efficiency and (2) investigate the correlation between the incoming wave height and the OWC front wall draught for a maximum efficiency via testing several front lip draughts for two different rear lip draughts under two wave heights and a constant PTO damping. It is found that the 2D and wave flume modelling of an offshore OWC significantly overestimate the overall power extraction efficiency, especially for wave frequencies higher than the chamber resonant frequency. Furthermore, a front lip submergence equal to the wave amplitude affords maximum efficiency whilst preventing air leakage, hence it is recommended that the front lip draught is minimized.

Item Details

Item Type:Refereed Article
Keywords:offshore oscillating water column, OWC, experimental and CFD results, wave energy, 3D effects, front and rear lip effects
Research Division:Engineering
Research Group:Maritime engineering
Research Field:Ocean engineering
Objective Division:Energy
Objective Group:Renewable energy
Objective Field:Wave energy
UTAS Author:Elhanafi, A (Dr Ahmed Elhanafi)
UTAS Author:MacFarlane, G (Associate Professor Gregor MacFarlane)
UTAS Author:Fleming, A (Dr Alan Fleming)
UTAS Author:Leong, Z (Dr Zhi Leong)
ID Code:115288
Year Published:2017
Web of Science® Times Cited:41
Deposited By:NC Maritime Engineering and Hydrodynamics
Deposited On:2017-03-15
Last Modified:2018-04-19

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