Turbulence modeling of a wave boundary layer on a rough bottom

The original k-ω model by Wilcox (WL) and two versions of blended k-ω/k-ε model, namely; Baseline (BSL) model and Shear Stress Transport (SST) model were applied to the wave boundary layers on a rough bottom. The model results were compared with the available experimental data. The three models show good agreement with the experimental data for velocity, turbulent kinetic energy and Reynolds stress. The SST model is superior in predicting shear velocity in one of the experimental cases. However, a detailed comparison revealed that SST model underestimates the friction factor for lower values of particle excursion length to roughness ratio, whereas, WL and BSL models showed good agreement with the experimental data. The results of this study would be useful for practicing engineers and researchers in choosing an appropriate model for calculating bottom shear stress.