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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

On the use of computational models for wave climate assessment in support of the wave energy industry

Hiles, Clayton E. 02 November 2011 (has links)
Effective, economic extraction of ocean wave energy requires an intimate under- standing of the ocean wave environment. Unfortunately, wave data is typically un- available in the near-shore (<150m depth) areas where most wave energy conversion devices will be deployed. This thesis identities, and where necessary develops, ap- propriate methods and procedures for using near-shore wave modelling software to provide critical wave climate data to the wave energy industry. The geographic focus is on the West Coast of Vancouver Island, an area internationally renowned for its wave energy development potential. The near-shore computational wave modelling packages SWAN and REF/DIF were employed to estimate wave conditions near-shore. These models calculate wave conditions based on the off-shore wave boundary conditions, local bathymetry and optionally, other physical input parameters. Wave boundary condition were sourced from theWaveWatchIII off-shore computational wave model operated by the National Oceanographic and Atmospheric Administration. SWAN has difficulty simulating diffraction (which can be important close to shore), but is formulated such that it is applicable over a wide range of spatial scales. REF/DIF contains a more exact handling of diffraction but is limited by computational expense to areas less than a few hundred square kilometres. For this reason SWAN and REF/DIF may be used in a complementary fashion, where SWAN is used at an intermediary between the global-scale off-shore models and the detailed, small scale computations of REF/DIF. When operating SWAN at this medium scale a number of other environmental factors become important. Using SWAN to model most of Vancouver Island's West Coast (out to the edge of the continental shelf), the sensitivity of wave estimates to various modelling param- eters was explored. Computations were made on an unstructured grid which allowed the grid resolution to vary throughout the domain. A study of grid resolution showed that a resolution close to that of the source bathymetry was the most appropriate. Further studies found that wave estimates were very sensitive to the local wind condi- tions and wave boundary conditions, but not very sensitive to currents or water level variations. Non-stationary computations were shown to be as accurate and more computationally efficient than stationary computations. Based on these findings it is recommended this SWAN model use an unstructured grid, operate in non-stationary mode and include wind forcing. The results from this model may be used directly to select promising wave energy development sites, or as boundary conditions to a more detailed model. A case study of the wave climate of Hesquiaht Sound, British Columbia, Canada (a small sub-region of the medium scale SWAN model) was performed using a high resolution REF/DIF model. REF/DIF was used for this study because presence of a Hesquiaht Peninsula which has several headlands around which diffraction was thought to be important. This study estimates the most probable conditions at a number of near-shore sites on a monthly basis. It was found that throughout the year the off-shore wave power ranges from 7 to 46kW/m. The near-shore typically has 69% of the off-shore power and ranges from 5 to 39kW/m. At the near-shore site located closest to Hot Springs Cove there is on average 13.1kW/m of wave power, a significant amount likely sufficient for wave power development. The methods implemented in this thesis may be used by groups or individuals to assess the wave climate in near-shore regions of the West Coast of Vancouver Island or other regions of the world where wave energy extraction may be promising. It is only with detailed knowledge of the wave climate that we can expect commercial extraction of wave energy to commence. / Graduate
32

Novel design and implementation of a permanent magnet linear tubular generator for ocean wave energy conversion /

Prudell, Joseph H. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 105-106). Also available on the World Wide Web.
33

Towards reliable and survivable ocean wave energy converters /

Brown, Adam C. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 45-48). Also available on the World Wide Web.
34

Investigation and comparison of generators for dynamic operation in ocean buoys /

Schacher, Anthony Clinton. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2005. / Printout. Includes bibliographical references (leaf 89). Also available online.
35

Towards reliable and survivable ocean wave energy converters

Brown, Adam C. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2010. / Title from PDF title page (viewed Aug. 22, 2009). Includes bibliographical references (leaves 45-48).
36

Estimating oceanic internal wave energy from seismic reflector slope spectra

Helfrich, L. Cody. January 2008 (has links)
Thesis (M.S.)--University of Wyoming, 2008. / Title from PDF title page (viewed on June 24, 2009). Includes bibliographical references.
37

A linear test bed for characterizing the performance of ocean wave energy converters /

Hogan, Peter M. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 125-126). Also available on the World Wide Web.
38

Optimal design of Hagen-Cockerall raft

Haren, Pierre January 1979 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 120-121. / by Pierre Haren. / M.S.
39

ENERGY OF THE SEA: AN OFFSHORE MARINE RESEARCH FACILITY

CRIPE, BENJAMIN IAN 28 June 2007 (has links)
No description available.
40

Co-design Investigation and Optimization of an Oscillating-Surge Wave Energy Converter

Grasberger, Jeffrey Thomas 19 January 2023 (has links)
Ocean wave energy has the potential to play a crucial role in the shift to renewable energy. In order to improve wave energy conversion techniques, a recognition of the sub-optimal nature of traditional sequential design processes due to the interconnectedness of subsystems such as the geometry, power take-off, and controls is necessary. A codesign optimization in this paper seeks to include effects of all subsystems within one optimization loop in order to reach a fully optimal design for an oscillating-surge wave energy converter. A width and height sweep serves as a brute force geometry optimization while optimizing the power take-off components and controls using a pseudo-spectral method for each geometry. An investigation of electrical power and mechanical power maximization also outlines the contrasting nature of the two objectives to illustrate electrical power maximization's importance for identifying optimality. The codesign optimization leads to an optimal design with a width of 12 m and a height of 10 m. The power take-off and controls systems are also examined more in depth to identify important areas for increased focus during detailed design. Ultimately, the codesign optimization leads to a 61.4% increase in the objective function over the optimal design from a sequential design process while also requiring about half the power take-off torque. / Master of Science / Ocean wave energy has the potential to play a crucial role in the shift to renewable energy sources. The Earth's vast oceans have immense energy potentials throughout the world, which often follow the seasonal trends of electricity demand in temperate climates. Wave energy harvesting is a technology which has been studied significantly, but has not yet experienced commercial success, partially due to the lack of convergence on a type of wave energy converter. In order to improve wave energy conversion techniques and support the convergence on a particular type, a recognition of the sub-optimal nature of traditional sequential design processes due to the interconnectedness of subsystems is necessary. A codesign optimization in this paper seeks to include effects of all subsystems within one optimization loop in order to reach a fully optimal design for an oscillating-surge wave energy converter. A width and height sweep serves as a brute force geometry optimization while optimizing the power take-off and control components for each geometry. The codesign optimization leads to an optimal design with a width of 12 m and a height of 10 m. Ultimately, the codesign optimization leads to a 62% increase in performance over the result from a sequential design process.

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