2‐D Depth‐Averaged Flow Computation near Groyne

The depth‐averaged velocity and bottom shear stress distributions in a rectangular channel near a groyne are computed by using a 2‐D depth averaged model. The model uses a hybrid finite difference scheme and an iterative method to solve the governing equations of flow and turbulence transport. Due to streamline curvature effects in the region near the groyne tip, a correction factor is incorporated into the k‐ε turbulence model that significantly improves the agreement between the computed and experimental data of the velocities and of the streamline pattern compared to previous numerical methods. In this region the bottom shear stress is found to be largely influenced by the 3‐D effects. A 3‐D correction factor is introduced which considerably improves the computed bottom shear stresses. Sensitivity analysis is made on the k‐ε model coefficients and on the correction factors of the streamline curvature and the 3‐D effects. The experimental errors in the velocity and bottom shear stress measurements are analyzed. The average errors between the computed and previous experimental results are presented with confidence intervals.