The directional characteristics of breaking waves generated by the directional focusing in a wave basin

Abstract

A directional wave focusing is formulated and applied to generate three-dimensional breaking waves in multidirectional wave basin. Based on the theoretical development, an experimental scheme for the generation of directional breaking waves in model basin is established. The characteristics of breaking waves are analyzed in a view of focusing efficiency and the effects of associated parameters, such as the directional range, frequency width and center frequency, on the wave focusing are studied in detail. An experimental investigation of the maximum amplitude distribution, the evolution of time series and spectrums during the wave packet propagation, and the variation of the water surface parameters is extensively carried out. It reveals that the focusing wave characteristics are significantly influenced by the wave directionality and the breaking criteria for directional waves are distinctly different from those for unidirectional waves.