Computational Fluid Dynamics Analysis of Integrated Needle-Nozzle Dynamics in Pelton Turbines: Insights from Cañón del Pato Hydroelectric Plant, Peru

Abstract This study presents a detailed computational fluid dynamics analysis of the needle -nozzle interaction in a Pelton turbine and its influence on jet formation and energy transfer efficiency. Using operational data from the Cañon del Pato hydroelectric plant in Peru, the research addresses key aspects of impulse turbine fluid dynamics, including jet velocity profiles, and torque generation in buckets. High resolution meshing and advanced turbulence modelling are employed to accurately the interaction between water jets and turbine buckets. The numerical results show strong agreement with measured data, achieving a torque deviation of 7.46%. The analysis also demonstrates that needle and nozzle alignment play a critical role in jet quality, producing a non-uniform velocity profile in which boundary layer effects reduce the jet-core velocity by approximately 12% near the bucket impact region. This work contributes to advancing computational fluid dynamic methodologies for hydropower applications by integrating experimental validation in order to optimise turbine design in future works. The findings have broader implications for improving efficiency and reliability in aging Pelton turbines globally, addressing challenges such as cavitation, erosion, and fatigue. By bridging computational and experimental approaches, this study offers a robust framework for analysing fluid dynamics and supports future developments in hydropower technology.