NUMERICAL ANALYSIS OF FLOW FIELD IN THE FRANCIS TURBINE

Abstract

The Francis turbine, a widely used hydraulic turbine, plays a crucial role in hydropower generation. Optimizing its performance and efficiency is of paramount importance in the pursuit of sustainable and cost-effective energy solutions. This study aims to conduct a comprehensive numerical analysis of the flow field within Francis turbines using advanced Computational Fluid Dynamics (CFD) techniques. The primary objectives of this research are twofold. Firstly, it seeks to develop detailed visualizations and quantitative representations of key flow parameters, including pressure contours, velocity contours, shear wall contours, and velocity streamlines for each turbine component. Secondly, it endeavors to compare and analyze the variations in pressure, velocity, shear wall, and mass flux between the inlet and outlet regions of the turbine. The numerical simulations are performed using state-of-the-art Commercial CFD code, which employs sophisticated numerical algorithms and turbulence models to accurately capture the complex flow dynamics within the turbine. The simulations are based on high-fidelity three-dimensional geometries of Francis turbine components, ensuring realistic representations of the flow domain. The pressure contours generated in this study provide valuable insights into the pressure distribution throughout the turbine, enabling the identification of regions with high or low pressure, which can significantly impact the turbine's performance and structural integrity. Velocity contours and streamlines offer a comprehensive understanding of the flow patterns, highlighting areas of high velocity and potential flow separations or recirculation zones. Shear wall contours are crucial in assessing the shear stresses acting on the turbine components, which can contribute to erosion and cavitation, potentially leading to premature component failure. Additionally, the analysis of mass flux variations between the inlet and outlet regions provides crucial information for optimizing the turbine's mass flow distribution and minimizing energy losses. The findings of this study have significant implications for the design, optimization, and operation of Francis turbines. The detailed visualizations and quantitative data generated through the CFD simulations can guide turbine manufacturers and designers in identifying potential areas for improvement, such as modifying component geometries, optimizing flow conditions, or implementing advanced flow control techniques. Furthermore, the comparative analysis of inlet and outlet variations offers insights into the impact of turbine geometry and flow conditions on critical parameters, enabling the development of design guidelines and operational strategies to maximize efficiency and minimize potential issues like cavitation or erosion.