Hydrodynamic processes on beach: Wave breaking, up-rush, and backwash

This paper presents two-dimensional numerical predictions of wave breaking, up-rush, and backwash in inner surf and swash zones and analyzes the hydrodynamic processes involved. In the numerical simulations, the Reynolds Averaged Navier–Stokes (RANS) equations, a non-linear k–ε turbulence closure, and a piecewise linear interface construction volume of fluid (PLIC-VOF) method are employed. On the basis of a series of model calibration using experimental data, plunging and spilling breakers are simulated at different wave parameters and slope angles. The numerical results indicate that there are non-linear interactions between hydrodynamic characteristics in surf zones such as wave breaking heights and those in swash zones such as up-rush heights, and the breaker type plays an important role in hydrodynamic processes in the two zones.

Research highlights
► Hydrodynamic phenomena in surf and swash zones are simultaneously simulated.
► There is non-linear interaction between flow fields in the two zones.
► The flow fields in inner surf and swash zones are strongly affected by breaker types.
► The hydrodynamics in inner surf and swash zones is described by ξ0, Re, Fr and St.
► The maximums of turbulent kinetic energy and dissipation rates increase with ξ0.