ABSTRACT
Sediment deposition in the artificial Lake Mills was computed using a three-dimensional numerical model. The model solved the Navier-Stokes equations together with the k- turbulence model. The sedimentation and the resulting bed elevation changes were computed by solving the convection-diffusion equation for suspended sediments and bed load, in combination with the Engelund-Hansen sediment transport formula. The free surface was computed with an algorithm based on the computed pressure field. A non-orthogonal unstructured adaptive grid was used, moving vertically and horizontally with the computed location of the bed and the free water surface. Large moving recirculation zones in the lake were observed in the results from the CFD model. The computed shape of the delta varied according to the prescribed downstream water level. A constant water level gave a longer and narrower delta, while a fluctuating water level gave a wider geometrical shape.
