Solitary wave interaction with porous breakwaters is studied by using a two-dimensional numerical model. In this model, flows outside of porous media are described by Reynolds-averaged Navier-Stokes equations. For porous flows, the spatially averaged Navier-Stokes equations, in which the effect of porous media is considered by including additional inertia and drag forces, are derived and implemented. The drag force is modeled according to Morison’s equation assuming uniform spherical particles within porous media. The corresponding drag force coefficient is expressed as the function of Reynolds number and hence the proposed porous flow model is valid in a wide range of porous flow regimes, i.e., laminar (linear friction), transitional, and turbulent (nonlinear friction) flows. The numerical model is validated against available theories and experimental data for both long wave and solitary wave interaction with porous breakwaters. The model is then employed to study solitary wave interaction with fully eme...

Numerical study of solitary wave interaction with porous breakwaters

Wave transformation due to multiple bottom-standing porous barriers

Experimental study on the performance of the multiple-layer breakwater

A study on the improvement for the problem of wave transmission in deeply submerged break- water is carried out in this paper. In the theoretical analysis the complex eigenfunction approach is employed. In this study the submerged breakwater is assumed to be a rectangular form and vertically stratified with multislice porous material. Theoretical computations are performed for both single-slice (nonstratified) and mul- tislice submerged breakwaters. Half of the water depth is selected as the submergence of the breakwater. The computational results show that, for a single-slice breakwater, the transmission coefficient could be effectively reduced, while the porosity of structure material is as high as 0.8 and the thickness-depth ratio b/h =2 0 (b is the structure thickness, and h is the water depth). A large transmission coefficient can be predicted for a deeply submerged breakwater without sufficient thickness-depth ratio. However, this problem could be improved by adopting a multislice structure concept in which the breakwater structures with more slices are more effective in reducing the transmission coefficient.

Cheng-Chung Chieu

Papers

A highly wave dissipation offshore breakwater