Numerical Studying the Effects of Division Angle of Rectangular Channel Branches on the Flow Field

Generally, intakes are used for conveying and diverting the flow within main channels and rivers. In this study, a flow field was simulated using FLOW-3D software. In addition, the flow free-surface variations were predicted using the Volume of Fluid (VOF) scheme. The flow turbulence was estimated by standard k-ε and RNG k-ε turbulence models. For instance, the MAE values for standard k-ε and RNG k-ε models to simulate the free surface profile were computed 0.166 and 0.201, respectively. The modeling results showed that the numerical model simulated the flow field with an acceptable accuracy. For example, the RMSE, MAE and R values for the simulated flow free-surface variations were calculated 0.164, 0.158 and 0.997 percent, respectively. Then, the effects of four flow division angles (30, 45, 75 and 90 degrees) on flow field pattern were considered. Regarding the modeling results, the highest depth-averaged velocity was obtained for the model with 45-degree. Among the models with division angles of 30, 45 and 75 degrees, the maximum shear stress was predicted for the model with 45-degree.