Experimental Validation of CFD Modeling of Multiphase Flow through Open Channel Confluence

Channel confluences are of considerable importance in river engineering and some hydraulic structures. Their flow structures have a great impact on measurement results, erosion, sediment transport and pollutant dispersion in confluence regions. A three-dimensional side discharge into a cross channel flow is simulated by a computational fluid dynamic software based Reynolds Stress Model (RSM). Effects of the discharge ratios (upstream discharge/combined discharge) on the size of the velocity fields upstream of junctions and the recirculation zone are also investigated in detail. The correlation formulas for recirculation length and width depending on discharge ratio for a junction of 30 degrees are proposed.