Análisis numérico del lavado hidráulico (flushing) de un embalse.

Abstract

This work develops the numerical simulations of the reservoir flushing, using the finite difference method, applied with the commercial software FLOW 3D. The RANS turbulence model k-ω was used to predict the liquid phase, while the Meyer-Peter Müller model was applied to estimate the sediment drag. The numerical simulations were carried out three-dimensionally in a transitory state. The results present an analysis of the specific case of the Toachi dam, located in the province of Santo Domingo de los Tsachilas in Ecuador. An analysis of the flow from the reservoir to the bottom drains is presented, as well as the sediment removed, starting from a critical condition of accumulation of solid material in the area near the dam, once the two bottom drains come into operation, with a 100% aperture. In this process, the predominant size of the accumulated sediments is considered, as well as their height in the area near the dam. An important factor for the analysis corresponds to the shape of the reservoir basin that remains at the close of the construction phase of the project, scheduled for 2021. For validation, the numerical results have been compared with the experimental study in physical model, carried out by the Escuela Politécnica Nacional in 2012. Finally, it is shown that the best alternative for the Toachi-Pilatón project is to form an approach channel to the bottom drains to improve the efficiency of the hydraulic flushing.