Numerical studies of submerged moored box-type floating breakwaters with different shapes of cross-sections using SPH

Numerical investigations and optimizations of typical submerged box-type floating breakwaters using SPH

Numerical and experimental investigation on the hydrodynamic characteristics of an arc-shaped plate-type breakwater under the action of long-period waves

A comparative study of the hydrodynamic characteristics of permeable twin-flat-plate and twin-arc-plate breakwaters based on physical modeling

Experimental study on the dynamic response of a water ballast type floating breakwater

Experimental investigation on hydrodynamic effectiveness of a water ballast type floating breakwater

Comprehensive experimental and numerical studies have been undertaken to investigate wave energy dissipation performance and main influencing factors of a lower arc-plate breakwater. The numerical model, which considers nonlinear interactions between waves and the arc-plate breakwater, has been constructed by using the velocity wavegenerating method, the volume of fluid (VOF) method and the finite volume method. The results show that the relative width, relative height and relative submergence of the breakwater are three main influencing factors and have significant influence on wave energy dissipation of the lower arc-plate open breakwater. The transmission coefficient is found to decrease with the increasing relative width, and the minimum transmission coefficient is 0.15 when the relative width is 0.45. The reflection coefficient is found to vary slightly with the relative width, and the maximum reflection coefficient is 0.53 when the relative width is 0.45. The transmission and reflection coefficients are shown to increase with the relative wave height for approximately 85% of the experimental tests when the relative width is 0.19−0.45. The transmission coefficients at relative submergences of −0.04, −0.02 and 0 are clearly shown to be greater than those at relative submergences of 0.02 and 0.04, while the reflection coefficient exhibits the opposite relationship. After the wave interacts with the lower arc-plate breakwater, the wave energy is mainly converted into transmission, reflection and dissipation energies. The wave attenuation performance is clearly weakened for waves with greater heights and longer periods.

Wave Attenuation Performance and the Influencing Factors of A Lower Arc-Plate Breakwater

A process-based 3D numerical model for surfzone hydrodynamics and beach evolution was established. Comparisons between the experimental data and model results proved that the model could effectively describe the hydrodynamics, sediment transport feature and sandbar migration process in the surfzone with satisfactory precision. A series of numerical simulations on the wave breaking and shoaling up to a barred beach were carried out based on the model system. Analyzed from the model results, the wave-induced current system in the surfzone consists of two major processes, which are the phase-averaged undertow caused by wave breaking and the net drift caused by both of the nonlinear wave motion and surface roller effect. When storm waves come to the barred beach, the strong offshore undertow along the beach suppresses the onshore net drift, making the initial sandbar migrate to the seaside. Under the condition of calm wave environment, both the undertow and net drift flow to the shoreline at the offshore side of the sandbar, and then push the initial sandbar to the shoreline. The consideration of surface roller has significant impact on the modeling results of the sandbar migration. As the roller transfer rate increases, the sandbar moves onshore especially under the storm wave condition.

Numerical modeling of the undertow structure and sandbar migration in the surfzone

In this study, wave generation is simulated using the velocity wave generation method. A damping wave dissipation region is established to eliminate wave reflection at the flume tail. Fluid motion is described using the Navier–Stokes equations. The water free surface is captured using the volume of fluid method. A 2D numerical model for the interactions between waves and plate-type open breakwaters is constructed using the finite volume method, and their correctness is validated by experimental results. Based on these models, two plate-type open breakwaters are compared in terms of the wave transmission coefficient (Kt), wave reflection coefficient (Kr), wave energy dissipation coefficient (Kd) and wave energy distribution. By comprehensively considering Kt, Kr, Kd and the wave energy distribution, the double-arc plate-type open breakwater is found to exhibit higher wave dissipation performance.

Weijun Guo

Papers

Experimental investigation on hydrodynamic effectiveness of a water ballast type floating breakwater

Wave Attenuation Performance and the Influencing Factors of A Lower Arc-Plate Breakwater

Numerical modeling of the undertow structure and sandbar migration in the surfzone

Numerical study of the wave dissipation performance of two plate-type open breakwaters based on the Navier–Stokes equations