Numerical simulation of scour at the rear side of a coastal revetment

This paper presents the results of a numerical modeling study on the scouring of unprotected rear side material of a rubble mound coastal revetment due to the overtopping of solitary-like waves utilizing a coupled hydro-morphodynamic computational fluid dynamics (CFD) model. Three cases having various wave heights are tested with six different turbulence models together with different wall functions. The hydrodynamic results (free-surface elevations, overtopping volumes, and jet thicknesses) and morphological results (scour profile and scour hole properties) are compared with the existing experimental data to evaluate the performances of different turbulence models and wall functions. It is found that the numerical model can predict the hydrodynamic and morphological results with a high level of accuracy when the appropriate turbulence model and wall function are used. The importance of turbulence in the scouring processes and the turbulence modeling approach in hydro-morphodynamic CFD simulations are highlighted.