Flow and sediment simulation around spur dike with free surface using 3-D turbulent model

Treatments of irregular boundary, bed deformation and free surface are main problems in 3-D flow and sediment model. Based on control equations of turbulent flow considering irregular boundary from liquid-solid two phase flow theory, the k-ɛ model and the Wall Function are adopted to develop a new model. In the model, apart from k-ɛ model and the Wall Function, the VOF method and the porosity concept are adopted to simulate water surface, irregular boundary and bed deformation. Using the new model, flow field, changing of water level, turbulent kinetic energy and its dissipation rate, and local scour-deposition around spur dike are simulated. Computed result is compared with experimental data. The model developed can successfully simulate the separating structure of flow and circumfluence around the spur dike, secondary flow in the circumfluence area, scour hole profile and bed contours and agree well with the experimental data.