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Pneumatic power measurement of an oscillating water column converter

Thesis (MScEng)--Stellenbosch University, 2014.

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Bibliographic Details
Main Author: Kooverji, Bavesh
Other Authors: Van Niekerk, J. L.
Format: Thesis
Language:en_ZA
Published: Stellenbosch : Stellenbosch University 2014
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access_status_str Open Access
author Kooverji, Bavesh
author2 Van Niekerk, J. L.
author_browse Kooverji, Bavesh
Van Niekerk, J. L.
author_facet Van Niekerk, J. L.
Kooverji, Bavesh
author_sort Kooverji, Bavesh
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (MScEng)--Stellenbosch University, 2014.
format Thesis
id oai:scholar.sun.ac.za:10019.1/86662
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:41:42.083Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2014
publishDateRange 2014
publishDateSort 2014
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/86662 Pneumatic power measurement of an oscillating water column converter Kooverji, Bavesh Van Niekerk, J. L. Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering. Pneumatic power -- Measurement Wave mechanics Air-flow -- Measurement Oscillating Water Column -- Testing Dissertations -- Mechanical and mechatronic engineering Flumes Oscillations UCTD Theses -- Mechanical and mechatronic engineering Thesis (MScEng)--Stellenbosch University, 2014. ENGLISH ABSTRACT: A measurement device was developed to accurately determine the pneumatic power performance of an Oscillating Water Column (OWC) model in a wave flume. The analysis of the pneumatic power is significant due to the wave-topneumatic energy being the primary energy conversion process and where the most energy losses can be expected. The aim of the research study is to address the accurate pneumatic power measurement of unsteady and bidirectional airflow in OWC model experiments. The two fundamental measurements required for the pneumatic power measurement are the pressure difference over an orifice on the OWC model and the volumetric flow rate of air through the outlet. The designed, constructed and assembled measurement device comprised of a venturi flow meter, containing a hot-film anemometer, which could measure the pressure drop and the volumetric flow rate in one device. The assembled pneumatic power measurement device was calibrated in a vertical wind tunnel at steady state. The results from the calibration tests showed that the volumetric flow rate measurements from the pneumatic power measurement device was accurate to within 3 % of the wind tunnel’s readings. The pneumatic power measurement device was incorporated onto a constructed Perspex physical model of a simple OWC device. This assembled system was used as the test unit in the wave flume at Stellenbosch University (SUN). The results from the experimental tests underwent comparative analysis with three analytical OWC air-flow models which were simulated as three scenarios using Matlab Simulink. These results showed that the measurement device has the ability to measure the pneumatic power but there is difficulty in modelling the complex air-flow system of the OWC device. This results in varying levels of agreement between the experimental and simulated pneumatic power results. The research study has revealed that there is difficulty in designing an accurate device for a wide range of test parameters due to the variance in output values. The unsteady and bidirectional nature of the air flow is also difficult to accurately simulate using a one-dimensional analytical model. Recommendations for further investigation are for CFD systems to be used for the analysis of the air-flow in an OWC system and to be used to validate future pneumatic power measurement devices. AFRIKAANSE OPSOMMING: ‘n Meetinstrument was ontwikkel om die pneumatiese kraglewering van ‘n model van die Ossillerende Water Kolom (OWK) golfenergie omsetter in ‘n golf tenk akkuraat te meet. Dit is belangrik om die omskakeling van golf na pneumatiese energie te analiseer siende dat die grootste energieverlies in dié proses plaasvind. Die doel van hierdie navorsingsprojek was om die akkurate pneumatiese kragmeting van variërende en twee-rigting vloei van lug in ‘n OWK model na te vors. Die twee fundamentele metings wat benodig word vir die pneumatiese kragbepaling is die drukverskil oor die vloei vernouing en die volumetriese vloeitempo van lug deur die uitlaat van die toetstoestel. Die spesiaal ontwerpte meettoestel wat gebruik is in die eksperiment het bestaan uit ‘n venturi vloeimeter wat ‘n verhitte-film anemometer bevat het wat die drukverandering en die volumetriese vloeitempo kan meet in ‘n enkele instrument. Die pneumatiese kragmeting was gekalibreer in ‘n vertikale windtonnel waarin ‘n konstante vloei tempo geïnduseer was. Die kalibrasieproses het bevestig dat die meettoestel metings lewer met ‘n fout van minder as 3 % wanneer dit vergelyk word met die bekende konstante vloei tempo soos bepaal in die windtonnel. ‘n Fisiese model van ‘n vereenvoudigde OWK golfenergie omsetter was ontwerp en gebou uit Perspex om as toetstoestel te gebruik vir die evaluering van die ontwerpte pneumatiese kraglewering meettoestel. Die toetse was uitgevoer in ‘n golftenk by die Universiteit Stellenbosch (SUN). The toetsresultate was vergelyk met drie ander OWK lugvloei modelle wat gesimuleer was deur om die analitiese modelle op te stel en te simuleer in Matlab Simulink. Die vergelyking van modellering resultate het gewys dat die meettoestel die vermoë het om pneumatiese krag te meet. Daar was wel komplikasies met die modellering van die komplekse lugvloei in die OWK toestel, die resultate het geen definitiewe ooreenstemming gewys tussen die eksperimentele en gesimuleerde pneumatiese krag resultate nie. Die navorsingsprojek het gewys dat daar komplikasies is om ‘n enkel toestel te ontwerp wat oor ‘n wye bereik kan meet weens die variasie van die verskillende parameters. Die variërende en twee-rigting lugvloei is ook moeilik om akkuraat te simuleer met ‘n een-dimensionele analitiese simulasie model. Aanbevelings vir verdere navorsing sluit in om die lugvloei in die OWK stelsel te modelleer en te analiseer in ‘n drie-dimensionele model om die lesings van ‘n pneumatiese krag meettoestel te bevestig. 2014-04-16T17:31:18Z 2014-04-16T17:31:18Z 2014-04 Thesis http://hdl.handle.net/10019.1/86662 en_ZA Stellenbosch University xv, 113 p. : ill. application/pdf Stellenbosch : Stellenbosch University
spellingShingle Pneumatic power -- Measurement
Wave mechanics
Air-flow -- Measurement
Oscillating Water Column -- Testing
Dissertations -- Mechanical and mechatronic engineering
Flumes
Oscillations
UCTD
Theses -- Mechanical and mechatronic engineering
Kooverji, Bavesh
Pneumatic power measurement of an oscillating water column converter
title Pneumatic power measurement of an oscillating water column converter
title_full Pneumatic power measurement of an oscillating water column converter
title_fullStr Pneumatic power measurement of an oscillating water column converter
title_full_unstemmed Pneumatic power measurement of an oscillating water column converter
title_short Pneumatic power measurement of an oscillating water column converter
title_sort pneumatic power measurement of an oscillating water column converter
topic Pneumatic power -- Measurement
Wave mechanics
Air-flow -- Measurement
Oscillating Water Column -- Testing
Dissertations -- Mechanical and mechatronic engineering
Flumes
Oscillations
UCTD
Theses -- Mechanical and mechatronic engineering
url http://hdl.handle.net/10019.1/86662
work_keys_str_mv AT kooverjibavesh pneumaticpowermeasurementofanoscillatingwatercolumnconverter