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Design and development of a novel wave energy converter

Thesis (PhD)--Stellenbosch University, 2013.

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Main Author: Joubert, James Rattray
Other Authors: Van Niekerk, J. L.
Format: Thesis
Language:en_ZA
Published: Stellenbosch : Stellenbosch University 2013
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access_status_str Open Access
author Joubert, James Rattray
author2 Van Niekerk, J. L.
author_browse Joubert, James Rattray
Van Niekerk, J. L.
author_facet Van Niekerk, J. L.
Joubert, James Rattray
author_sort Joubert, James Rattray
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (PhD)--Stellenbosch University, 2013.
format Thesis
id oai:scholar.sun.ac.za:10019.1/85817
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:44:39.798Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2013
publishDateRange 2013
publishDateSort 2013
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/85817 Design and development of a novel wave energy converter Joubert, James Rattray Van Niekerk, J. L. Retief, G. de F. Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering. Wave-power-extracting-caisson-breakwater Ocean wave power Wave energy conversion Electric power production Dissertations -- Mechanical and mechatronic engineering Theses -- Mechanical and mechatronic engineering Thesis (PhD)--Stellenbosch University, 2013. ENGLISH ABSTRACT: The design, development and evaluation of a novel wave energy converter (WEC) device, called the ShoreSWEC, in a South African port development is presented. Based on the device requirements, site selection criteria were specified and applied to identify a suitable deployment location. A wave modeling procedure was developed to determine the operational wave conditions and available wave power resource at the selected location. The site was found to have a low mean annual average resource of approximately 2.3 kilowatt per meter wave crest (kW/m) due to its relatively sheltered location. The wave model was further used to determine design storm conditions and a structural stability analysis of the device was conducted. Experimental tests were performed to evaluate the hydrodynamic conversion efficiency of a single chamber of the device at its most conservative orientation, under a variety of wave energy conditions. The effect of a floor incline and an additional chamber on the performance of the system was investigated. The incline improved efficiency for low wave heights, making it ideal for the low wave power resource conditions of the site, whilst the multi-chamber system experienced increased performance at high wave periods. A comparison between the ShoreSWEC and a conventional oscillating water column (OWC) WEC showed that the OWC extracted 72% more energy, highlighting the sensitivity of performance on device orientation. A three-dimensional (3D) numerical model of the experimental setup was developed. The numerical model provided comparable water surface elevations inside the flume and chamber, yet predicted significantly higher internal chamber pressures and overall efficiency. The electricity generation potential of a 10 chamber ShoreSWEC at the specified location, approximated from the experimental results and 11 years of hindcast wave data, was found to be 6 kW on average for a 15 kW capacity system. Results of this study highlighted the need for greater understanding of the hydrodynamic characteristics of a full length device. Experimental tests in a 3D wave basin on a scaled full length ShoreSWEC model are therefore recommended. Once conducted, South Africa will be one step closer to the deployment of the full scale SWEC device. AFRIKAANSE OPSOMMING: Die ontwerp, ontwikkeling en evaluasie van ‘n unieke golfenergieomsetter (GEO), genaamd die ShoreSWEC, in ‘n Suid-Afrikaanse haweontwikkeling word aangebied. Terrein evaluasie kriteria, gebaseer op die omsettervereistes, is ontwikkel en toegepas om die mees belowende terrein te identifiseer. ‘n Golfmodeleringsprosedure is ontwikkel om die operasionele golfkondisies en beskikbare golfdrywinghulpbron te bepaal. Daar is gevind dat die terrein ‘n lae gemiddelde golfdrywing van bykans 2.3 kilowat per meter golfkruin het as gevolg van die beskutte ligging. Die golfmodel is verder gebruik om ontwerpstormkondisies te bepaal en ‘n stabiliteitsanalise was op die toestel struktuur uitgevoer. Eksperimentele toetse van verskeie golfenergie kondisies is gedoen om die hidrodinamiese omsettingseffektiwiteit van ‘n enkel kamer van die toestel te bepaal teen sy konserwatiefste orientasie. Die effek van ‘n vloerhelling en ‘n addisionele kamer op die uitsette van die sisteem is ondersoek. Die helling het effektiwiteit verbeter vir lae golfhoogtes wat dit ideaal maak vir die lae hulpbron by die terrein, terwyl die veelvoudige-kamer-sisteem beter gevaar het by hoë golfperiodes. ‘n Vergelyking tussen die ShoreSWEC en ‘n konvensionele ossilerende waterkolom (OWK) GEO het gewys dat die OWK 72% meer energie onttrek. Dit beklemtoon die sisteem se sensitiwiteit vir die inkomende golfrigting. ‘n Drie-dimensionele (3D) numeriese model van die eksperimentele opstelling is ontwikkel. Die numeriese model het aansienlik hoër drukke binne die kamer, en gevolglik algehele effektiwiteit, voorspel as die eksperimentele toetse. Die elektriese opwekkingskapasiteit van ‘n 10 kamer ShoreSWEC by die terrein, gebaseer op die eksperimentele resultate en 11 jaar se golfdata, is bereken as 6 kW gemiddeld vir ‘n 15 kW kapasiteit stelsel. Die bevindinge van hierdie studie het die behoefte aan ‘n beter begrip van die hidrodinamiese eienskappe van ‘n vollengte sisteem beklemtoon. Eksperimentele toetse in ‘n 3D golfbak op ‘n geskaleerde vollengte ShoreSWEC model word dus aanbeveel. Sodra dit voltooi is, sal Suid-Afrika een stap nader wees aan die ontplooiing van ‘n volskaalse SWEC toestel. Doctoral 2013-05-03T09:22:55Z 2013-12-13T17:14:35Z 2013-05-03T09:22:55Z 2013-12-13T17:14:35Z 2013-12 Thesis http://hdl.handle.net/10019.1/85817 en_ZA Stellenbosch University xviii, 150 p. : ill. application/pdf Stellenbosch : Stellenbosch University
spellingShingle Wave-power-extracting-caisson-breakwater
Ocean wave power
Wave energy conversion
Electric power production
Dissertations -- Mechanical and mechatronic engineering
Theses -- Mechanical and mechatronic engineering
Joubert, James Rattray
Design and development of a novel wave energy converter
title Design and development of a novel wave energy converter
title_full Design and development of a novel wave energy converter
title_fullStr Design and development of a novel wave energy converter
title_full_unstemmed Design and development of a novel wave energy converter
title_short Design and development of a novel wave energy converter
title_sort design and development of a novel wave energy converter
topic Wave-power-extracting-caisson-breakwater
Ocean wave power
Wave energy conversion
Electric power production
Dissertations -- Mechanical and mechatronic engineering
Theses -- Mechanical and mechatronic engineering
url http://hdl.handle.net/10019.1/85817
work_keys_str_mv AT joubertjamesrattray designanddevelopmentofanovelwaveenergyconverter