3D simulation of flow around a single spur dike with free-surface flow

Abstract

In the present study, flow patterns around a single spur dike (also termed a groyne) with free-surface flow was simulated using a numerical model known as Fluent. The model solved the fully three-dimensional, Reynolds-averaged Navier–Stokes equation to predict flow near the structure where three-dimensional flow is dominant. To treat the complex free-surface flow, the volume of fluid method with geometric reconstruction scheme was applied and turbulence was simulated using standard equations. In this research work, both a structured and an unstructured mesh were used and the density of the mesh spacing was selected the highest near the walls and also free surface to obtain more accurate results. Comparison of free surface and velocities of 3D model showed good agreement with three experimental flume data obtained by other researchers. The reattachment length for various conditions was computed using the numerical results and flow pattern was presented for repelling, attracting and vertical spur dikes together. Also, bed-shear stress distribution was presented and the effects of flow discharge and the length and angle of the spur dike upon the bed shear-stress distribution were evaluated.