Effects of turbulence models on numerical simulations of wave breaking and run-up on a mild slope beach

The performance of the standard k-ɛ model, the high-Reynolds-number k-ω model, the 1-equation k model, and the non-friction Euler model is examined against the case of wave run-up on a mild slope. A numerical model based on N-S equations and Volume Of Fluids (VOF) method is employed. Comparisons of elevation, velocity and shear stress are made among the four turbulence models against experimental data of wave run-up on a mild slope beach. It is found that before wave breaking on the slope, the outputs of the four different turbulence models agree reasonably well with each other. This suggests that during the run-up process the turbulence effect is negligible before wave breaking. Moreover, in the wave breaking zone, both the standard k-ɛ model and the high-Reynolds-number k-ω model predict the mean velocity field quite well, but generally under-predict the velocity and turbulent kinetic energy using wall functions on the solid slope surface.