Numerical Simulation Of Overtopping Against Sea Dikes With Fence Panels In Regular Waves

The Sea dike plays an important role in costal defense projects. It was used to protect the land in coastal area from the effects of waves and storm surges. The research on interaction of water waves and structures and overtopping discharge is one of the major problems in sea dikes design. This paper aims at establishing a numerical wave flume that could simulate the overtopping process in regular waves with accurate describing fence panels.Based on the Reynolds-averaged Navier-Stokes equations, the Volume of Fluid method and the RNG k-epsilon turbulence model, a numerical wave flume was formulated in the framework of two phase mixture flow model. The numerical model can simulate the overtopping process in regular waves against a sea dike with fence panels. Regular wave overtopping against a sea dike of simple profile was also simulated for validation of the numerical model. Comparing the computed overtopping discharge with published physical model data and other numerical results for the case without fence panels, it was proved that the numerical model can predict overtopping discharge reasonably.Numerical simulations of overtopping against sea dikes with fence panels were carried out. The computed depth averaged velocity of overtopping flows on the dike crest were obtained and compared with the physical model result. It shows that fence panels can reduce the max depth averaged velocity. The velocity fields and turbulent energy dissipation rate fields near the wall of sea dike with fence panels were discussed to look insight the effects of fence panels on the energy dissipation and the overtopping discharge reduction. Comparison of the overtopping discharge shows that sea dikes with fence panels can reduce about 20% overtopping discharge.