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Tidal energy device hydrodynamics in non-uniform transient flows / JOHN CHAPMAN

Swansea University Author: JOHN CHAPMAN

Abstract

Tidal energy devices convert the flow of water induced by the tidal cycle into useful energy. Presently the most common type of tidal energy device is a horizontal axis zero head turbine. Conceptually the form of these devices is similar to modern wind turbine systems. This thesis presents the devel...

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Published: 2008
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
URI: https://cronfa.swan.ac.uk/Record/cronfa42229
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spelling 2020-09-03T09:42:59.9294185 v2 42229 2018-08-02 Tidal energy device hydrodynamics in non-uniform transient flows b105dfb01764241e776d1cf9ea6d0c07 JOHN CHAPMAN JOHN CHAPMAN true false 2018-08-02 Tidal energy devices convert the flow of water induced by the tidal cycle into useful energy. Presently the most common type of tidal energy device is a horizontal axis zero head turbine. Conceptually the form of these devices is similar to modern wind turbine systems. This thesis presents the development of a flexible code that models the hydrodynamic behaviour of a tidal stream turbine rotor and its supporting structure in a non-uniform, time varying flow. Blade Element Momentum Theory (BEMT) is reviewed and its implementation is discussed. Corrections to the theory are reviewed in the context of operation in an ocean environment. The completed model operates in a three-dimensional representation of the ocean and includes the calculation of supporting structure loads using Morison's equation. The flow regime either includes boundary layer effects and a calculated wave climate or can be taken from data measured with an ADCP. Specific model features are introduced that allow realistic appraisal of the system's performance and load regime as well as specific situations such as braking of the rotor. The capability of the code is then demonstrated using a non-uniform, time varying flow and the importance of this in the design of turbine systems is discussed. The novel features introduced in this thesis are; the inclusion of non rotor-normal inflow in the BEMT equations, a new, robust approach to solving the BEMT equations and a novel blade-off modelling approach. A calibrated marine tower shadow model, a novel procedure for comparing the performance of alternative device concepts and a method to input ADCP data directly to the model system were also novel steps introduced in the thesis. E-Thesis Environmental engineering.;Ocean engineering.;Fluid mechanics.;Alternative Energy. 31 12 2008 2008-12-31 COLLEGE NANME COLLEGE CODE Swansea University Doctoral Ph.D 2020-09-03T09:42:59.9294185 2018-08-02T16:24:28.4953823 Faculty of Science and Engineering School of Engineering and Applied Sciences - Uncategorised JOHN CHAPMAN 1 0042229-02082018162438.pdf 10797931.pdf 2018-08-02T16:24:38.2000000 Output 22482748 application/pdf E-Thesis true 2018-08-02T00:00:00.0000000 false
title Tidal energy device hydrodynamics in non-uniform transient flows
spellingShingle Tidal energy device hydrodynamics in non-uniform transient flows
JOHN CHAPMAN
title_short Tidal energy device hydrodynamics in non-uniform transient flows
title_full Tidal energy device hydrodynamics in non-uniform transient flows
title_fullStr Tidal energy device hydrodynamics in non-uniform transient flows
title_full_unstemmed Tidal energy device hydrodynamics in non-uniform transient flows
title_sort Tidal energy device hydrodynamics in non-uniform transient flows
author_id_str_mv b105dfb01764241e776d1cf9ea6d0c07
author_id_fullname_str_mv b105dfb01764241e776d1cf9ea6d0c07_***_JOHN CHAPMAN
author JOHN CHAPMAN
author2 JOHN CHAPMAN
format E-Thesis
publishDate 2008
institution Swansea University
college_str Faculty of Science and Engineering
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hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Engineering and Applied Sciences - Uncategorised{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Engineering and Applied Sciences - Uncategorised
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description Tidal energy devices convert the flow of water induced by the tidal cycle into useful energy. Presently the most common type of tidal energy device is a horizontal axis zero head turbine. Conceptually the form of these devices is similar to modern wind turbine systems. This thesis presents the development of a flexible code that models the hydrodynamic behaviour of a tidal stream turbine rotor and its supporting structure in a non-uniform, time varying flow. Blade Element Momentum Theory (BEMT) is reviewed and its implementation is discussed. Corrections to the theory are reviewed in the context of operation in an ocean environment. The completed model operates in a three-dimensional representation of the ocean and includes the calculation of supporting structure loads using Morison's equation. The flow regime either includes boundary layer effects and a calculated wave climate or can be taken from data measured with an ADCP. Specific model features are introduced that allow realistic appraisal of the system's performance and load regime as well as specific situations such as braking of the rotor. The capability of the code is then demonstrated using a non-uniform, time varying flow and the importance of this in the design of turbine systems is discussed. The novel features introduced in this thesis are; the inclusion of non rotor-normal inflow in the BEMT equations, a new, robust approach to solving the BEMT equations and a novel blade-off modelling approach. A calibrated marine tower shadow model, a novel procedure for comparing the performance of alternative device concepts and a method to input ADCP data directly to the model system were also novel steps introduced in the thesis.
published_date 2008-12-31T03:52:33Z
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score 11.037581