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Combined transmission and diffraction around a floating breakwater Garceau, Nathalie

Abstract

Wave conditions on the sheltered side of a floating breakwater are commonly approximated by supperposing the results of the transmitted wave field across the breakwater, and the diffracted wave field around the ends of the breakwater, both obtained separately. This thesis describes an experimental and numerical investigation of the suitability of this approach. To evaluate the wave field downwave of the breakwater, three set of laboratory tests were conducted. One relates diffraction around a fixed breakwater extending to the seabed; another to the two-dimensional case of wave transmission across a breakwater located at the water surface; and the third to the three-dimensional case of combined wave transmission and diffraction past a breakwater at the water surfaces. The experiments were carried out for a rectangular caisson with three wave conditions and for both a fixed and freely floating breakwater. Three numerical models of a rectangular breakwater based on linear potential theory were used to predict results relating to transmission coefficient in the case of wave transmission only, wave diffraction only and combined wave transmission and diffraction. The results from the laboratory experiments and the numerical models were compared to validate the numerical models. Also, the addition of the transmission and diffraction solutions were compared with the combined solution, on the basis of experimental results as well as numerical results. The numerical and experimental results have indicated that the superposition approximation generally overestimates the combined situation, particularly for longer waves.

Item Metadata

Title
Combined transmission and diffraction around a floating breakwater
Creator
Garceau, Nathalie
Publisher
University of British Columbia
Date Issued
1997
Description
Wave conditions on the sheltered side of a floating breakwater are commonly approximated by supperposing the results of the transmitted wave field across the breakwater, and the diffracted wave field around the ends of the breakwater, both obtained separately. This thesis describes an experimental and numerical investigation of the suitability of this approach. To evaluate the wave field downwave of the breakwater, three set of laboratory tests were conducted. One relates diffraction around a fixed breakwater extending to the seabed; another to the two-dimensional case of wave transmission across a breakwater located at the water surface; and the third to the three-dimensional case of combined wave transmission and diffraction past a breakwater at the water surfaces. The experiments were carried out for a rectangular caisson with three wave conditions and for both a fixed and freely floating breakwater. Three numerical models of a rectangular breakwater based on linear potential theory were used to predict results relating to transmission coefficient in the case of wave transmission only, wave diffraction only and combined wave transmission and diffraction. The results from the laboratory experiments and the numerical models were compared to validate the numerical models. Also, the addition of the transmission and diffraction solutions were compared with the combined solution, on the basis of experimental results as well as numerical results. The numerical and experimental results have indicated that the superposition approximation generally overestimates the combined situation, particularly for longer waves.
Extent
5488354 bytes
Genre
Thesis/Dissertation
Type
Text
File Format
application/pdf
Language
eng
Date Available
2009-03-12
Provider
Vancouver : University of British Columbia Library
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
DOI
10.14288/1.0050241
URI
http://hdl.handle.net/2429/5950
Degree
Master of Applied Science - MASc
Program
Civil Engineering
Affiliation
Applied Science, Faculty of; Civil Engineering, Department of
Degree Grantor
University of British Columbia
Graduation Date
1997-05
Campus
UBCV
Scholarly Level
Graduate
Aggregated Source Repository
DSpace

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For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.