A Numerical Study on Three-Dimensionality and Turbulence in Supercritical Bend Flow

A numerical study is carried out to investigate the importance of three-dimensionality and turbulence in supercritical bend flow. The CFD-based model, FLUENT, is applied for solving the three-dimensional equations of continuity and Navier-Stokes. The volume of fluid method has been employed to simulate the free-surface flow. The turbulence closure of the mean flow system is acquired using the standard k - epsilon turbulence model. The model is applied to three different bend geometries. The three-dimensional modeling is done with and without considering turbulence effects. Results, in the form of non-dimensional water-surface profiles, are compared with the available two-dimensional model results as well as available experimental data. The results indicate that three-dimensional approach makes highly improved predictions in comparison with the results of two-dimensional model. Furthermore, the height and the location of maximum flow depth, which are important in designing the supercritical bend channels, are predicted better in three-dimensional model than the two-dimensional model results. However, turbulence modeling does not show a significant contribution in supercritical bend flow.