Design of a single-channel wear test device for the Francis-99 turbine guide mechanism and sediment wear testing

This study employed a design method for a single-channel sediment wear test device based on numerical simulation and the principle of similarity to investigate the characteristics of solid–liquid two-phase flow and the sediment wear mechanism of the Francis-99 turbine under sand-containing conditions. The design of the test device and the sediment wear tests for the diversion components of the Francis-99 turbine were conducted, and the similarity of the flow field was validated. The findings indicate that under the design conditions of the single-channel sediment wear test device and the prototype, the surface sediment particle velocity range for the stay vane is 1.4–1.8 m/s, while that for the guide vane is 1.1–6.2 m/s. The sediment particle velocity difference near the wall is about 0.02 m/s, and the sediment distribution pattern is relatively similar. The difference in the impact angle of sediment particles at the heads of the stay vane and guide vane is about 0.1°. The wear rate on the stay vane surface ranges from 0.1 to 0.4 μm/h, and on the active guide vane surface, it ranges from 0.1 to 0.55 μm/h, with the maximum wear rate occurring near the tail area. The single-channel sediment wear test device described in this paper effectively reveals the wear mechanism of hydraulic turbine diversion components and demonstrates high feasibility.