Two-dimensional depth-averaged modeling of flow in curved open channels

The application of the depth-averaged De St. Venant equations for open channel numerical models dictate the adoption of hydrostatic pressure distribution. They are thus applicable to cases where vertical details are not significant. The alternative two-dimensional vertically averaged and moment equations model, in which more vertical details are accounted for, is used to analyze problems involved in curved channels of various curvature. The distribution of horizontal velocity components is assumed to be linear, while the vertical velocity and pressure is quadratic. The implicit Petrov-Galerkin finite element scheme is used in these simulations. Computed values for water surface profile, depth-averaged longitudinal and transverse velocities across the channel width and vertical profiles of longitudinal and transverse velocities are compared with experimental data. The comparison shows a good agreement between the simulated results and experimental data. In addition, this study recommends the supplement of the standard conventional De St. Venant model by the proposed model on simulating strongly curved flows. Finally, the use of refined finite element meshes is recommended only when some of the details near the channel edges are sought.