Modeling of emerged semi-circular breakwater performance against solitary waves using SPH method

Abstract

The semicircular breakwater (SBW) is a composite breakwater consisting of a hollow empty reinforced concrete caisson seated on the rubble mound breakwater. In this research, smoothed particle hydrodynamics (SPH) method was used to examine the run-up and overtopping of solitary waves on SBW. At first the SPH model was validated for regular wave–SBW interaction against experimental results. Comparisons showed that the present modified numerical model has a good agreement with experimental data. Parametric study was then performed on the effect of water depth and wave height of the single solitary waves and height of the rubble mound on wave run-up. Furthermore, double solitary waves were generated to study their interaction with SBW by the model. Run-up and reflection coefficient for double solitary wave–structure interaction was then investigated. The results show that in sum run-up in double solitary wave mode is smaller than that of single solitary wave. Moreover, the second solitary wave run-up is smaller than that of the first solitary wave in double solitary wave train. Overtopping discharge of double solitary wave is nearly constant for τ/T greater than 1.3, where τ/T is the ratio of time distance between wave crests of double wave to effective period of single solitary wave. Also overtopping discharge decreases with increasing in τ/T for its value smaller than 1.3. The results show that this model is a useful tool for simulating the interaction of solitary waves–structures with complicated geometry.