Hydrodynamic performance of a new box-type breakwater with superstructure: Experimental study and SPH simulation

This paper proposes a new box-type breakwater with superstructure arranged near free surface. The hydrody-namic performance of this new breakwater is studied through experimental tests and numerical simulations. A series of laboratory tests are carried out to measure the transmission coefficient, reflection coefficient and energy dissipation coefficient of the breakwater. A numerical model solving wave interaction with the proposed breakwater is developed by using delta-SPH (Smoothed Particles Hydrodynamics) method, which can give a better understanding on the energy-dissipating process. The numerical model is validated by comparing the numerical results with the experimental data. Based on the experimental and numerical results, the hydrodynamic per-formance of the proposed breakwater is compared with that of the box-type breakwater, and the multi-parameter analyses are conducted to clarify the deck width effect on the hydrodynamic performance of the proposed breakwater. The results show that compared with the box-type breakwater, the proposed breakwater can dissipate more wave energy and thus has lower transmission and reflection coefficients. The wave energy dissipation by the proposed breakwater is mainly due to the turbulence, wave breaking and vortex shedding. A larger deck width for the proposed breakwater is more conducive to dissipating the energy of longer period waves.