Numerical study of wave transmission over double submerged breakwaters using non-hydrostatic wave model

In the present work, a non-hydrostatic wave model SWASH (an acronym of Simulating WAves till SHore) is used to simulate the wave transmission over double trapezoidal submerged breakwaters. The numerical results were compared with the results of the physical model. The comparison indicated the capability of SWASH model to predict the wave transmission over double submerged breakwaters. Influencing factors such as breakwater spacing S/L0, where L0 is the deep-water wavelength, and current were investigated in detail. Moreover, the effects of current on wave transmission were also analyzed. When the relative submerged depth R/H, where R is the submerged depth and H is the wave height, remains at 1.0, the appropriate relative breakwater spacing S/L0 is about 1.11. Current has no obvious effect on the appropriate S/L0, but it will change the shape of wave spectrum. Dissipation of super harmonic wave components is more obvious than that of lower harmonic wave components.