Computational fluid dynamics aided optimization of guide vane and runner of a francis hydroturbine

Today's and future energy needs are among the most important issues. Energy consumption continues to increase rapidly, and the worldwide demand for coal and other fossil fuels is decreasing. In addition to the development of new renewable energy sources, current energy production methods should be as efficient as possible to supply the energy need in the future. Modern technologies in power plants should be developed and turbochargers should be optimized so that existing energy sources can be used more economically. At this point, the development of hydroelectric power plants, which are widely used in the world and take first place in renewable energy sources, is of great importance. While hydraulic turbines used in hydroelectric power plants are being developed, important hydraulic performance parameters such as efficiency, cavitation and power have to meet the determined requirements. Computational Fluid Dynamics (CFD) analyses are very useful in terms of time, cost and accuracy in order to be able to realize turbine designs and examine flow characteristics of these turbines. With the developing computer technology, design optimizations combining CFD and various optimization methods can be realized. In this study, a Francis-type hydraulic turbine was optimized with a design optimization system based on CFD analyses, with the guide vane and the runner components separately. In the guide vane optimization, the efficiency is maximized and the loss of head is reduced by using the single-objective optimization method. In the runner optimization, a cavitation-free design is provided, while a single-objective and multi-objective optimization method is used to maximize efficiency and power. Keywords: Computational fluid dynamics, Francis turbine, Optimization