Numerical Study of Wave Dynamics over Island Reefs Based on Smoothed Particle Hydrodynamics Method

Coastal areas are suffering from an increasing number of hazards like storm surge or flooding. Luckily, reefs can reduce the risk because of their particular wave dynamic characteristics. In this study, a numerical wave flume is established to simulate the topography of fringing reefs around islands. The smoothed particle hydrodynamics- (SPH-) finite particle method (FPM) scheme is used to deal with Navier–Stokes equations, and the boundary repulsion method is used to deal with the solid wall boundary. The wave propagating and breaking processes over island reefs under regular wave incidence are simulated. The results are compared with the experimental results in the literature, showing that the numerical model can simulate the wave propagating process on the island reef terrain very well. The wave propagation over the island reef terrain experienced the processes of shoaling, breaking, reforming, and so on, and most waves break in the plunging form. The processes of wave-induced setup accompanied with wave breaking before and after the reef ridge were also simulated.