Application of the two-fluid model to prediction of sediment transport in turbulent open channel flow

Abstract

The two-fluid model (TFM) formulation was used to predict the liquid and sediment transport in an open channel flow for dilute concentrations. A low-Reynolds-number k–ε model was used to represent the turbulence in the liquid phase; it included the effect of the sediment particles on the turbulence field. The particle-wall interactions were implemented using the boundary condition of Johnson and Jackson (1987), which resulted in a finite value for the sediment velocity at the bottom wall. The values of the specularity coefficient and coefficient of restitution for the particle-wall collisions were specified. Overall, the TFM prediction for the liquid velocity, sediment concentration, and turbulent statistics agreed well with two different experimental test cases by Lyn (1987). A key parameter for determining the sediment phase transport was the granular temperature, the level of which was set by the value of the specularity coefficient at the wall. In the context of the TFM, the presence of the sediment particles was found to enhance the wall shear stress of the liquid phase.