Analysis of cause and research on repair of sidewall damage to flip bucket under high-altitude conditions

The cavitation conditions of spillway flip buckets under different air pressures are completely different. Aiming at the special cavitation problem of the side wall of the tipping bucket under the condition of low air pressure, an experimental study was carried out at an altitude of 3000 m. The Froude criterion based scaling method and numerical simulation method were used to study the flip bucket. First, the velocity distribution of the flip bucket under the flood discharge of the scaled model is measured to verify the accuracy and reliability of the hydraulic scaling test. Second, the location of cross flow in the flip bucket is determined. Third, based on the position of side flow separation, a more ideal flip bucket structure is proposed by numerical simulation. The experimental and numerical results show that the distribution of the low pressure area on the side wall of the flip bucket is highly consistent with the prototype observation results, but the absolute pressure near the side wall is low and the cavitation number σ is small. The research results greatly reduce the uncertainty of directly optimizing the flip bucket structure and provide theoretical reference and improvement suggestions for the design of the flip bucket structure under low pressure.