Numerical Simulation of Hydrodynamics and Sediment Transport in the Surf and Swash Zone Using OpenFOAM®

Abstract

This study focuses on the numerical investigation of the 3D hydrodynamic processes of coastal zones such as wave breaking, wave-induced currents, and sediment transport, using the multiphase, interFoam solver of OpenFOAM® (a state-of-the-art, open-source CFD numerical tool). The numerical scheme is suitably framed by initial conditions of wave propagation and absorption using waves2Foam wave library. The turbulence closure problem is handled using a buoyancy modified k–ω SST model. In order to predict the sediment transport rate due to waves and currents (bed load, sheet flow, and suspended load over ripples), a transport-rate formula involving unsteady aspects of the sand transport phenomenon is implemented. For the suspended load in the surf zone, the Bailard formula is adopted after considering that the dissipation mechanism is the wave breaking. Results concerning wave height, longshore current, turbulence kinetic energy, and sediment transport are compared against experimental data and semi-empirical expressions.