Author(s): Zhao Canhua
Linked Author(s): Shuangke Sun
Keywords: Discharge tunnel; Drop shaft; Annular hydraulic jump; Diversion tunnel
Abstract: This paper describes the hydraulic model study and theoretical analysis on the discharge tunnel with vortex-flow drop shaft, which is to be used in Xiaowan Project. Based on experimental observations, arrangement of the drop structure was optimized, which is simple in shape and applicable for the condition of higher water head above 200m and large discharge above 1400m3/s. The model tests show the pressure distribution on the wall of the drop structure, and the higher ratio of energy dissipation. The flow field in the drop shaft has three components: air core region, annular hydraulic jump and water cushion region. In the theoretical analysis, flow velocity, pressure distribution, thickness of the flow, and cavitation number in the air core region are figured out and the results agree the experimental data well.