Effects of sediment characteristics on the erosion of Pelton turbine.

As Pelton turbines are increasingly used in high mountain regions because of their unique advantage of high-water head adaptability, the hydraulic characteristics and multi-phase flow behaviour in Pelton turbines have attracted the attention of many scholars. Most notably, the presence of solid particles such as sand exists in natural river systems, which end up in the turbines, causing erosion. This has become an international academic issue which has not been fully developed yet. In this study, three-phase simulations based on Eulerian–Lagrangian methodology are conducted to investigate the erosion phenomenon, especially in the bucket region. Sediment particle characteristics such as size and concentration in both the distribution system and buckets region are analysed. The innovation of this study is that, unlike other erosion investigations, it focuses on the impact angle of the jet flow as this is a unique characteristic of Pelton turbines. Furthermore, the sediment particle's flow characteristics at different bucket rotating angles and how they influence the erosion mechanism are also investigated. Results reveal that larger particles cause greater erosion on the bucket. In small particle and standard diameter conditions, the impact angle is mostly below 5 $ ^\circ $ ∘ . Finally, this study presents the first successful attempt in using rotating angle to describe the erosion in a Pelton turbine. A corrected erosion model adapted to the Pelton turbine is given through regression and proves effective in predicting erosion. [ABSTRACT FROM AUTHOR]