Open Channel Flow Simulation (Sedimentation Problem in Rosaries Dam)

Abstract

Sedimentation problem, in Rosaries Dam, is one of the biggest problems facing the electrical hydropower generation, especially during autumn. Sedimentation reduces the storage capacity of the lake behind the dam and increases the cost of the MWH due to the high cost of silt removal. This thesis is about a CFD application (SSIIM program) used to describe and simulate the water flow and sediment concentration (considered as solid particles) in the reservoir. SSIIM is designed for the analysis of such phenomenon. Simulations were done for three types of sediments according to their diameters and taken into account that the turbine gates are fully opened and all other gates are closed. These simulations and analysis lead to suitable solutions for silt removal and by consequence reduce the cost of such operations. This study explains the direction of velocity vectors, vortices and sediment concentration that occur behind the dam in the three Cartesian coordinate (x, y and z). Results are presented, for samples of each type of sediment, for different longitudinal profiles and depths.