Diffraction of a Solitary Wave by an Infinitely Long Breakwater with a Gap

The theme of this study is to apply a three-dimensional fully-nonlinear water-wave model to simulate a solitary wave striking upon a long breakwater with an opening. It is assumed the wave is non-breaking and the effect of surface tension is negligible. For the numerical method, the Laplace equation of the velocity potential with complete nonlinear boundary conditions is solved through a finite-difference algorithm developed in this study. The transient boundary-fitted grid system is incorporated in the solver to capture the free surface. As a solitary wave impacts upon an infinitely long breakwater with a gap, part of the waves are reflected back from the breakwater (Region I) while some waves transmit through the opening into the shadow region (Region II). The present numerical solutions are compared with published data for model verification. In addition, the wave diffraction patterns according to the factors of incident solitary-wave amplitude and gap width are examined and discussed.