Three-dimensional Modelling of Flow in Curved Compound Open Channels

Flow in curved compound channels is completely three-dimensional. The centrifugal force intensifies the secondary currents and the interfaces between the main channel and the floodplains generate some new secondary current cells which grow from the bed towards the surface. In order to take into consideration all aspects of flow in these kinds of channels, numerical modelling is performed using an open source computation fluid dynamic (CFD) software, namely OpenFOAM. In the present study, the Reynolds Averaged Navier-Stocks equations (RANS) are solved, and a single-phase solver, simpleFoam, is applied with an appropriate boundary condition on the free-surface. Velocity profiles obtained from this model show a good accuracy in comparison with the experimental results. The distribution of boundary shear stress through the whole curve is presented.

Keywords:

Compound channel , open channel bend , OpenFOAM , Reynolds averaged Navier-Stocks equations