Analysis of the wave energy dissipation in the interaction between waves and horizontal plate breakwaters through the smoothed particle hydrodynamics

This paper presents a numerical comparison of the wave energy dissipation behaviors of a Horizontal Plate Breakwater (HPB), a Perforated HPB (PHPB), a Downward Twin HPB (DTHPB), and an Upward Twin HPB (UTHPB) through the Large Eddy Simulation (LES) model introduced in the Smoothed Particle Hydrodynamics (SPH) by Di Mascio et al. [Phys. Fluids 29, 035102 (2017)], known as δ-LES-SPH model. The majority of existing studies in this context concentrate on the analysis of structures' hydrodynamic coefficients, while an in-depth analysis of the wave dissipation process involved in the wave-structure interaction is lacking. The analyses presented in this paper address this research gap by considering the interactions between waves and the HPB, PHPB, DTHPB, and UTHPB through the calculation and comparison of the time evolutions of the dissipated wave energy of the water body in the vicinity of these structures. The numerical results demonstrate that for the HPB, the wave energy is dissipated in a violent manner in the water body above and behind the structure. In contrast, for the PHPB, the outflow from the slots on the structure collides with the water body in the vicinity of the slots, resulting in the dissipation of wave energy due to the presence of large velocity gradients. The similarity in the wave energy dissipation behavior of the HPB and DTHPB is evident, and the hydrodynamic coefficients including reflection, transmission, and wave energy dissipation coefficients of these two structures show insignificant differences. The UTHPB, on the other hand, exhibits a different wave energy dissipation behavior. One of the horizontal plate structures placed at the still water level results in a shallow water effect and wave breaking that occurs above the UTHPB to a lesser extent than that observed above the HPB.