NUMERICAL APPROACH TO IMPROVE FLUSHING EFFICIENCY BY A DYNAMIC MORPHOLOGICAL MODEL

The process of sediment flushing is simulated by a 3D numerical model in which sediment and flow interaction are reflected in the reservoirs. RANG equations are solved numerically by finite volume with a k-epsilon turbulence model. The convection-diffusion equation for the sediment concentration is solved. The Van-Rijn's reference level concentration equation is adopted as a boundary condition. Bed changes are obtained by application of sediment continuity equation. The numerical results show that the flushing efficiency is related to the outflow discharge, initial conditions of water level and number and location of the bottom outlets.