Author(s): Shangtuo Qian; Jianhua Wu; Fei Ma
Linked Author(s): Fei Ma, Jianhua Wu
Keywords: Low Froude number; Dragon-drop-tail spillway tunnel; Filling water; Local slope
Abstract: With the rapid constructions of high dam projects within China, the dragon-drop-tail spillway tunnel is introduced and widely used. Considering the high water head and large flow velocity on the dragon-drop-tail section, aerator devices are necessary for cavitation damage control. For the one placed in its initial position, it is a serious concern to design the suitable flow regime of the cavity and to control the cavity filling water due to the large flow depth and low Froude number through this aerator. In this study, the relationships between the construction parameters and the jet impact angle of the lower trajectory of the flow were theoretically analyzed for an aerator device with/without a local slope. Nine test cases with different geometries were designed, and the effectiveness of the filling water control was experimentally investigated under the different operation conditions. It is concluded that the cavity flow regime and filling water can be improved significantly if a suitable geometries of the local slope are designed.