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Alan Fleming - One of the best experts on this subject based on the ideXlab platform.

  • Model predictive control-based power take-off control of an Oscillating Water Column wave energy conversion system
    IOP Conference Series: Earth and Environmental Science, 2017
    Co-Authors: Gimara Rajapakse, Alan Fleming, Shantha Gamini Jayasinghe, Farhad Shahnia
    Abstract:

    Australia's extended coastline asserts abundance of wave and tidal power. The predictability of these energy sources and their proximity to cities and towns make them more desirable. Several tidal current turbine and ocean wave energy conversion projects have already been planned in the coastline of southern Australia. Some of these projects use air turbine technology with air driven turbines to harvest the energy from an Oscillating Water Column. This study focuses on the power take-off control of a single stage unidirectional Oscillating Water Column air turbine generator system, and proposes a model predictive control-based speed controller for the generator-turbine assembly. The proposed method is verified with simulation results that show the efficacy of the controller in extracting power from the turbine while maintaining the speed at the desired level.

  • Phase Averaged Flow Analysis in an Oscillating Water Column Wave Energy Converter
    Journal of Offshore Mechanics and Arctic Engineering, 2013
    Co-Authors: Alan Fleming, Irene Penesis, Laurie Goldsworthy, Gregor Macfarlane, Neil Bose, Tom Denniss
    Abstract:

    The paper presents the application of phase averaging to experimental data obtained during scale model testing of a forward facing bent duct Oscillating Water Column (OWC). Phase averaging is applied to both wave probe data and a two-dimensional velocity field at the centerline plane of the OWC model obtained using particle imaging velocimetry (PIV). Results are presented for one monochromatic wave condition. The influence of varied wave frequency is briefly discussed.

  • UnderWater Geometry optimization for an Oscillating Water Column ocean wave energy converter
    2012
    Co-Authors: Alan Fleming, Irene Penesis, Gregor Macfarlane, Neil Bose, Scott Hunter
    Abstract:

    This paper describes an experimental programme designed for the comparison of the performance of Oscillating Water Column (OWC) underWater geometry. The process described utilises two-dimensional (2D) Particle Imaging Velocimetry (PIV) data in conjunction with wave probe and pressure transducer data to provide qualitative and quantitative information. At present the testing scheme is limited to monochromatic waves and 2D based assumptions. A method is presented for qualitative comparison of candidate geometry. It is concluded that average-kinetic energy fields are a suitable qualitative process for ranking of candidate geometry.

  • Phase Averaged Flow Analysis in an Oscillating Water Column Wave Energy Converter
    Volume 5: Ocean Space Utilization; Ocean Renewable Energy, 2011
    Co-Authors: Alan Fleming, Irene Penesis, Laurie Goldsworthy, Gregor Macfarlane, Neil Bose, Tom Denniss
    Abstract:

    This paper presents the application of phase averaging to experimental data obtained during scale model testing of a forward facing bent duct Oscillating Water Column (OWC). Phase averaging is applied to both wave probe data and a two dimensional velocity field at the centreline plane of the OWC model obtained using PIV. Results are presented for one monochromatic wave condition. The influence of varied wave frequency is briefly discussed.Copyright © 2011 by ASME

Tom Denniss - One of the best experts on this subject based on the ideXlab platform.

  • Phase Averaged Flow Analysis in an Oscillating Water Column Wave Energy Converter
    Journal of Offshore Mechanics and Arctic Engineering, 2013
    Co-Authors: Alan Fleming, Irene Penesis, Laurie Goldsworthy, Gregor Macfarlane, Neil Bose, Tom Denniss
    Abstract:

    The paper presents the application of phase averaging to experimental data obtained during scale model testing of a forward facing bent duct Oscillating Water Column (OWC). Phase averaging is applied to both wave probe data and a two-dimensional velocity field at the centerline plane of the OWC model obtained using particle imaging velocimetry (PIV). Results are presented for one monochromatic wave condition. The influence of varied wave frequency is briefly discussed.

  • Phase Averaged Flow Analysis in an Oscillating Water Column Wave Energy Converter
    Volume 5: Ocean Space Utilization; Ocean Renewable Energy, 2011
    Co-Authors: Alan Fleming, Irene Penesis, Laurie Goldsworthy, Gregor Macfarlane, Neil Bose, Tom Denniss
    Abstract:

    This paper presents the application of phase averaging to experimental data obtained during scale model testing of a forward facing bent duct Oscillating Water Column (OWC). Phase averaging is applied to both wave probe data and a two dimensional velocity field at the centreline plane of the OWC model obtained using PIV. Results are presented for one monochromatic wave condition. The influence of varied wave frequency is briefly discussed.Copyright © 2011 by ASME

Deborah Greaves - One of the best experts on this subject based on the ideXlab platform.

  • Experimental investigation of different geometries of fixed Oscillating Water Column devices
    Renewable Energy, 2017
    Co-Authors: Thomas Vyzikas, Samy Deshoulières, Matthew Barton, Olivier Giroux, Deborah Greaves, Dave Simmonds
    Abstract:

    publisher: Elsevier articletitle: Experimental investigation of different geometries of fixed Oscillating Water Column devices journaltitle: Renewable Energy articlelink: http://dx.doi.org/10.1016/j.renene.2016.11.061 content_type: article copyright: © 2016 Elsevier Ltd. All rights reserved.

  • air Water two phase flow modelling of hydrodynamic performance of an Oscillating Water Column device
    Renewable Energy, 2012
    Co-Authors: Yali Zhang, Qingping Zou, Deborah Greaves
    Abstract:

    Abstract A numerical method based on a two-phase level set with the global mass correction and immersed boundary method is developed here to simulate wave interaction with a semi-submerged chamber. An Oscillating Water Column, where power is extracted due to a normally incident wave forcing the free surface of the fluid between the front wall and rear wall to oscillate, is studied numerically to examine its hydrodynamic characteristics. The numerical results for an OWC under various wave conditions are compared with published experimental data by Morris-Thomas et al. [Morris-Thomas TM, Irvin RJ, Thiagarajan KP. An investigation into the hydrodynamic efficiency of an Oscillating Water Column. J Offshore Mech Arct Eng 2007;129:273–8] and theory by Evans and Porter [Evans DV, Porter R. Hydrodynamic characteristics of an Oscillating Water Column device. Appl Ocean Res 1995;17:155–64]. The flow field, free surface and pressure distribution are presented at different instants in time to reveal the energy loss clearly. The hydrodynamic efficiency predicted by the numerical results demonstrates a banded efficiency centred about a resonant peak and agrees with the physical experiment more closely than with the inviscid linear theory. The effect of the various wave conditions, immersion depth, thickness of the front wall of the chamber, vortex generation around the front wall in the Water and air chamber characteristics on the efficiency of wave energy extraction from the OWC is investigated.

  • Air–Water two-phase flow modelling of hydrodynamic performance of an Oscillating Water Column device
    Renewable Energy, 2012
    Co-Authors: Yali Zhang, Qingping Zou, Deborah Greaves
    Abstract:

    Abstract A numerical method based on a two-phase level set with the global mass correction and immersed boundary method is developed here to simulate wave interaction with a semi-submerged chamber. An Oscillating Water Column, where power is extracted due to a normally incident wave forcing the free surface of the fluid between the front wall and rear wall to oscillate, is studied numerically to examine its hydrodynamic characteristics. The numerical results for an OWC under various wave conditions are compared with published experimental data by Morris-Thomas et al. [Morris-Thomas TM, Irvin RJ, Thiagarajan KP. An investigation into the hydrodynamic efficiency of an Oscillating Water Column. J Offshore Mech Arct Eng 2007;129:273–8] and theory by Evans and Porter [Evans DV, Porter R. Hydrodynamic characteristics of an Oscillating Water Column device. Appl Ocean Res 1995;17:155–64]. The flow field, free surface and pressure distribution are presented at different instants in time to reveal the energy loss clearly. The hydrodynamic efficiency predicted by the numerical results demonstrates a banded efficiency centred about a resonant peak and agrees with the physical experiment more closely than with the inviscid linear theory. The effect of the various wave conditions, immersion depth, thickness of the front wall of the chamber, vortex generation around the front wall in the Water and air chamber characteristics on the efficiency of wave energy extraction from the OWC is investigated.

David G. Dorrell - One of the best experts on this subject based on the ideXlab platform.

  • Multi–chamber Oscillating Water Column wave energy converters and air turbines: A review
    'Wiley', 2019
    Co-Authors: Shalby M, David G. Dorrell, Walker P
    Abstract:

    © 2018 John Wiley & Sons, Ltd. The Oscillating Water Column (OWC) is a more common type of wave energy converter (WEC) that has been the subject of the study and development for several decades. Multi–chamber Oscillating Water Column (MC–OWC) devices or arrays have the advantage of being more efficient in energy extraction compared to a single chamber system, particularly in more chaotic sea states. A variety of single and array OWC devices have been proposed and studied on a small–scale, whereas few large–scale devices have been tested under ocean wave conditions. This paper provides a concise review of the current state of MC–OWC device development in laboratory conditions. The review highlights explicitly the main stages of MC–OWC device development for one ongoing study as an example. This review was based on the available information in the literature from 2003 to 2012, in addition, further work is presented as part of the current study at the University of Technology Sydney. This study is from 2015 to 2018. The discussion shows the challenges that a device needs to overcome to be more competitive with other WECs in the global of wave energy converter area

  • Modelling of the multi-chamber Oscillating Water Column in regular waves at model scale
    Energy Procedia, 2017
    Co-Authors: Mohammad Shalby, Paul D. Walker, David G. Dorrell
    Abstract:

    Abstract This paper studies the reliability of numerical models used for estimating multi-chamber Oscillating Water Column (MC-OWC) response in the time-domain. The model for the internal Water surface level and instantaneous pressure inside the chamber at regular waves conditions using a hybrid system of hydrodynamic and thermodynamic rigid piston models without power take-off. Reliability is assessed using experimental data obtained from a wave tank used in the model concept validation. The results show the method could be extended to describe the hydrodynamics of the MC-OWC in regular and irregular wave conditions.

  • A Multichamber Oscillating Water Column Using Cascaded Savonius Turbines
    IEEE Transactions on Industry Applications, 2010
    Co-Authors: David G. Dorrell, Min-fu Hsieh, Chi-chien Lin
    Abstract:

    This paper describes a small segmented Oscillating Water Column (OWC) with three sections and the modelling techniques that can be used to simulate its performance. The turbine uses cascaded Savonius rotors and the unit is developed and tested for validation of the performance algorithms. It is shown that the systems can be easily described and developed. It would be suitable for a shoreline location such as a harbor wall, where waves are random and not orthogonal to the Column. Conversion rates in the region of 20% are tabulated for the system with an output of 25-W peak. A full algorithm used for the system is put forward and solved using the Runge-Kutta-Nystrom (RKN) method.

  • A multi-chamber Oscillating Water Column using cascaded Savonius turbines
    2009 IEEE Energy Conversion Congress and Exposition, 2009
    Co-Authors: David G. Dorrell, Min-fu Hsieh, Chi-chien Lin
    Abstract:

    This paper describes a small segmented Oscillating Water Column with three sections and the modeling techniques that can be used to simulate its performance. The turbine uses cascaded Savonius rotors and the unit is developed and tested for validation of the performance algorithms. It is shown that the systems can be easily described and developed. It would be suitable for a shoreline location such as a harbor wall, where waves are random and not orthogonal to the Column. Conversion rates in the region of 20 % are tabulated for the system with an output of 25 W peak. A full algorithm used for the system is put forward and solved using the Runge-Kutta- Nystrom Method.

  • a small segmented Oscillating Water Column using a savonius rotor turbine
    IEEE International Conference on Sustainable Energy Technologies, 2008
    Co-Authors: Chi-chien Lin, David G. Dorrell, Min-fu Hsieh
    Abstract:

    This paper outlines a project which addresses the use of a small segmented Oscillating Water Column with three sections. The turbine utilises cascaded Savonius rotors (one for each section) and this system is developed and tested for validation of the performance algorithms. It is shown that the systems can be easily described and a system developed that can generate. It would be suitable for a shoreline location such as a harbour wall, where waves are random and not orthogonal to the Column. Conversion rates in the region of 20 % are tabulated for the system with an output of 25 W peak. The paper will give a full algorithm for the system while the digest outlines some crucial points with regards to the sizing and operation of the Column with respect to the wave frequency and wavelength. The turbine is fully characterized - the generator is a brushless permanent magnet machine connected to a diode bridge rectifier and variable load.

Yali Zhang - One of the best experts on this subject based on the ideXlab platform.

  • air Water two phase flow modelling of hydrodynamic performance of an Oscillating Water Column device
    Renewable Energy, 2012
    Co-Authors: Yali Zhang, Qingping Zou, Deborah Greaves
    Abstract:

    Abstract A numerical method based on a two-phase level set with the global mass correction and immersed boundary method is developed here to simulate wave interaction with a semi-submerged chamber. An Oscillating Water Column, where power is extracted due to a normally incident wave forcing the free surface of the fluid between the front wall and rear wall to oscillate, is studied numerically to examine its hydrodynamic characteristics. The numerical results for an OWC under various wave conditions are compared with published experimental data by Morris-Thomas et al. [Morris-Thomas TM, Irvin RJ, Thiagarajan KP. An investigation into the hydrodynamic efficiency of an Oscillating Water Column. J Offshore Mech Arct Eng 2007;129:273–8] and theory by Evans and Porter [Evans DV, Porter R. Hydrodynamic characteristics of an Oscillating Water Column device. Appl Ocean Res 1995;17:155–64]. The flow field, free surface and pressure distribution are presented at different instants in time to reveal the energy loss clearly. The hydrodynamic efficiency predicted by the numerical results demonstrates a banded efficiency centred about a resonant peak and agrees with the physical experiment more closely than with the inviscid linear theory. The effect of the various wave conditions, immersion depth, thickness of the front wall of the chamber, vortex generation around the front wall in the Water and air chamber characteristics on the efficiency of wave energy extraction from the OWC is investigated.

  • Air–Water two-phase flow modelling of hydrodynamic performance of an Oscillating Water Column device
    Renewable Energy, 2012
    Co-Authors: Yali Zhang, Qingping Zou, Deborah Greaves
    Abstract:

    Abstract A numerical method based on a two-phase level set with the global mass correction and immersed boundary method is developed here to simulate wave interaction with a semi-submerged chamber. An Oscillating Water Column, where power is extracted due to a normally incident wave forcing the free surface of the fluid between the front wall and rear wall to oscillate, is studied numerically to examine its hydrodynamic characteristics. The numerical results for an OWC under various wave conditions are compared with published experimental data by Morris-Thomas et al. [Morris-Thomas TM, Irvin RJ, Thiagarajan KP. An investigation into the hydrodynamic efficiency of an Oscillating Water Column. J Offshore Mech Arct Eng 2007;129:273–8] and theory by Evans and Porter [Evans DV, Porter R. Hydrodynamic characteristics of an Oscillating Water Column device. Appl Ocean Res 1995;17:155–64]. The flow field, free surface and pressure distribution are presented at different instants in time to reveal the energy loss clearly. The hydrodynamic efficiency predicted by the numerical results demonstrates a banded efficiency centred about a resonant peak and agrees with the physical experiment more closely than with the inviscid linear theory. The effect of the various wave conditions, immersion depth, thickness of the front wall of the chamber, vortex generation around the front wall in the Water and air chamber characteristics on the efficiency of wave energy extraction from the OWC is investigated.