Author(s): Sun Shuangke; Xu Tibing; Xia Qingfu; Sun Gaosheng; Xie Weidong
Linked Author(s): Shuangke Sun
Keywords: Drop shaft; Circular intake; Stilling well; Energy dissipation
Abstract: The Dashimen Hydroelectric Power Station, of which the dam height is63.78m, is a multi-purpose project concerning the industry water supply, power generation, and flood control. The drop shaft spillway is only one outlet structure of this project and has a special conformation reconstructed from diversion tunnel, its maximum flow capacity is about 148m3/s. In this paper, hydraulic model test is carried out to study the hydraulic characteristics of this spillway and optimize the layout of stilling well. It is indicated that the spillway is safer than traditional spillway with the wall pressing flow since the sudden enlargement configuation under the circular intake can induce supercavitating flow in the vertical shaft. Otherwise, this spillway has high energy dissipation due to the full-developed aerated flow and optimized layout of stilling well. The damping ratio is above83.1% ～91.6%.