Numerical Simulation Study on Sediment Erosion Characteristics of Pelton Turbine

抄録

Pelton turbines are ideal for developing Asia’s abundant high-head water resources, but sediment-laden jets cause erosion that compromises their stable operation. This study employs Eulerian-Lagrangian method to simulate three-phase flow in a six-nozzle Pelton turbine, investigating bucket erosion under varying sediment concentrations and diameters. The findings indicate that erosion is primarily occurs in the splitter, the bucket root, and near the trailing edge. As sediment concentration rises, the erosion is intensified, and the erosion amount near the trailing edge increases most significantly, followed by the bucket root, while the erosion amount near the splitter changes little, and the overall erosion distribution has no obvious change. The increase of sediment diameter will intensify erosion, with large-diameter particles showing a greater tendency to induce erosion in the vicinity of the splitter. Near the trailing edge, the erosion induced by small-diameter particles is notably more severe than that caused by large-diameter particles. The impact of high-speed jet will form a continuous water sheet on the bucket, which effectively reduces the direct impact of particles on the wall, so that the bucket surface is less affected by erosion. Nevertheless, as sediment particles grow larger in diameter, the water sheet’s protective effect will be significantly weakened near the bucket root.