Numerical study of wave-induced flow and wave set-up on a platform reef with steep slope

Abstract

A 2D numerical model was developed in this study to investigate the wave-induced flow and wave set-up on a platform reef with steep frontal slope. The model solves the Reynolds Averaged Navier-Stokes (RANS) equations, with the classical k−ε turbulence closure model. The inflow boundary was modified by adding fluid replenishment to balance the water level in the numerical flume to ensure long-term simulation in the platform reef system. The numerical model was first validated by systematically comparing the wave breaking, flow structure, and mean water level against laboratory measurements. The validated model was employed to further analyze the detailed flow field and reveal the influence of the reef morphology on the wave-induced flow and wave set-up. The complex distribution pattern of wave-induced flow and wave set-up on the reef flat were found to be related to the Froude number. The results also reveal that reef slope and reef roughness will not only change the wave breaking morphology but also affect the distribution pattern of wave-induced flow and wave set-up.