Development of Three-Dimensional Numerical Model to Simulate Fluid Flow and Sediment Transport in the settling Basins

When high concentration of sediment is carried by the river, a settling basin design is required at the intake. In the present research, a three-dimensional numerical model was developed to simulate settling basin sedimentation. For the simulation, time averaged Navier-Stokes equations (RANS) as flow governing equations, convection-diffusion equation for suspended sediment concentration, and Van-Rijn bed load equation for boundary condition in the bed were used. Numerical solutions of the flow governing equations were suggested to be finite volume spatially and finite difference temporally. Decoupling procedure of the pressure was derived from MAC. Finite volume method was applied to discretise the convectiondiffusion equation for the suspended sediment equation. The predicted results proved comparable with the observed experimental data. Thereafter, the model was successfully applied to a real case study in Nekoabad settling basin.