3-D numerical simulation on overbank flows in compound channels

The 3-D k-ε turbulence hydrodynamic model in curvilinear coordinates is established to simulate the overbank flow in the curved channel with irregular terrain in this paper. Body-fitted coordinate is adopted in horizontal plane, part grid is adopted in vertical direction, wall-function method is employed to simulate the bed resistance. The model is applied to simulate the meandering channel with straight flood plain banks and the curved channel, the main velocities and the secondary velocities for all sections in longitudinal and cross-section are presented respectively. By contrasting and analyzing, the results of simulation are fit to reflect the results of experiment. These results show the value of application of the model for 3-D overbank flow.