Turbulent Free Surface Flow over a Gravel Bed

Turbulence in open-channel flow over a rough bed is very complex. Although many investigations have been undertaken, the current understanding of the roughness effect on the turbulent properties is still limited. In this paper, a numerical model study of turbulent free surface flow over a gravel bed is presented. A three-dimensional turbulent free surface flow model was developed to study the roughness effect on the turbulence properties and free surface. The model has been applied to an experiment of flow over a gravel bed and the predictions agree closely with the experimental data, thus it can be considered as a complementary approach to experimental investigations to gain further insight into the turbulent flow dynamics.