عنوان مقاله [English]
Incompressible viscous flow with moving free surface is an important phenomenon in nature which has broad application in engineering. For these flows, determination of the temporal and spatial position of this moving free surface under unsteady or non-uniform conditions is very difficult. One of the most complicated phenomena in the coastal zone is wave breaking. The study of these waves is of importance in many applications, such as destructive impact forces on marine structures, and cross-shore and long-shore sediment transport. Being highly nonlinear, transient and complex, a theoretical analysis of wave impact would be impossible without numerical simulations. In this study, fluid is considered as viscous and incompressible. Therefore, Navier-Stokes and continuity are considered as governing equations. To solve these equations, a finite volume method, based on the PISO algorithm, is used. The effect of turbulence was considered using the standard k-$varepsilon$ model. A two dimensional VOF model, using Donor-Acceptor algorithm as a simple line interface construction method, was developed for free surface modeling. A piston-type wave maker and Goring formula are used in the left lateral boundary condition to generate a shallow water solitary wave. A sloped beach is considered in right lateral boundary condition to simulate breaking wave. A pontoon floating breakwater is exposed to an incident wave. Euler equation is used to estimate pressure exerted on pontoon floating breakwater. To validate the present model, a dam break test is adopted as a benchmark. The results are compared with available data and show the accuracy of the developed model. Then, the velocity and pressure field, due to the interaction of a solitary wave and moored floating breakwater, was obtained, using a coupled VOF and N-S solver. To compare the effect of wave breaking force on the structure, the pontoon floating breakwater is located in and out of the breaking wave zone. The results showed that the breaking solitary wave implies much greater force than the non-breaking wave on the floating breakwater.