Modelagem fluidodinâmica computacional (CFD) do modelo reduzido do reservatório da PCH Salto do Paraopeba

Abstract

The siltation of reservoirs poses a significant challenge to the sustainable development of hydroelectric power generation, particularly in the Brazilian context, where hydroelectric plants play a crucial role in the energy matrix. Small Hydroelectric Plants emerge as important alternatives for complementary renewable energy generation. To optimize the design, construction, operation, and repowering of these SHPs, it is vital to study the hydrodynamics and sediment transport in their reservoirs. Three-Dimensional Computational Fluid Dynamics (CFD 3D) modeling emerges as the most suitable approach for dealing with complex flow issues. This study proposes a method to reproduce and evaluate hydrodynamic and sediment transport phenomena in the physical model of the Salto Paraopeba Small Hydroelectric Power Plant, located in Jeceaba, MG, which was deactivated due to the complete siltation of its water intake. The FLOW-3D software was used, whose verification was based on velocity measurements and observations of sediment bank formation in the reduced physical model built at the Hydraulic Research and Water Resources Center (CPH) of the Federal University of Minas Gerais. An efficient reproduction of the observed conditions in the experiment was demonstrated, despite the need for adjustments in the computational mesh and additional numerical validation analyses. Regarding the hydraulic model considering the clean reservoir, the discharge curve of the numerical model closely approached that measured in the reduced model. The variation in bed roughness played a crucial role in calibrating these models, influencing flow patterns. As for the simulation of sediment transport, the formation of the beach at the end resembled that of the reduced model, validating the use of the Meyer, Peter, and Muller (1948) equation for sediment transport calculations. The computational model results closely matched experimental observations, highlighting the consistency of the rubber characterization. The conception of this work demonstrated the efficiency of using a reduced model in validating the computational numerical model, given the dificulty of direct verification with measurements in the prototype, as well as some of the limitations encountered in this type of study.