Numerical Simulation of Breaking and Post-Breaking Wave Deformation Process Around a Submerged Breakwater

A numerical wave model for two-dimensional wave field in the vertical plane is proposed in this study. The model combines a VOF method with a non-reflective wave generator in addition to the open boundary treatment based on an added dissipation zone to achieve stable computations. Not only wave breaking due to a submerged breakwater, but also post-breaking wave deformation are numerically investigated using the proposed model. Extensive laboratory experiments were also conducted to verify the validity of the model. The breaking characteristics and the frequency spectra of wave amplitude are examined for various incident wave conditions and breakwater configurations. The computed and measured results have revealed that second harmonic free wave component is generated in the region of non-breaking reformed wave, and that a breaking wave-induced circulating flow is formed at the onshore side of the submerged breakwater. It is demonstrated that the proposed numerical wave model can reproduce well the wave deformation before and after wave breaking through comparison with the experimental results.