Summary: | 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. === Applied Science, Faculty of === Civil Engineering, Department of === Graduate
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