With the rapid development of high dam projects within China, the dragon-drop-tail spillway tunnel is introduced and widely used. In view of the high water head and the large flow velocity on the dragon-drop-tail sect...With the rapid development of high dam projects within China, the dragon-drop-tail spillway tunnel is introduced and widely used. In view of the high water head and the large flow velocity on the dragon-drop-tail section, aerator devices are usually placed for the cavitation damage control. For the device placed in its initial position, it is a serious concern to design a suitable flow regime of the cavity and to control the cavity filling water due to the large flow depth and the low Froude number through this aerator. In this study, the relationships between the geometries of the aerator device and the jet impact angle of the lower trajectory of the flow are theoretically analyzed with/without a local slope. Nine test cases with different geometries are designed, the effectiveness of the filling water control is experimentally investigated under different operation conditions, and two criteria of the local slope design are proposed. It is concluded that the cavity flow regime and the filling water can be improved if a small impact angle and some suitable geometries of the local slope are designed.展开更多
A new kind of ski-jump-step spillway was reported. By means of the effects of the aeration basin, it supplies the sufficient aeration flow from the first step for stepped chutes, especially for large unit discharge. T...A new kind of ski-jump-step spillway was reported. By means of the effects of the aeration basin, it supplies the sufficient aeration flow from the first step for stepped chutes, especially for large unit discharge. The physical model experiments demonstrated that, this spillway makes a far better hydraulic performance as regards energy dissipation and cavitation damage protection than the current and conventional stepped spillways, and the unit discharge can be enlarged from about 50 m3/s-60 m3/s.m to 118 m3/s.m in order to significantly reduce the width of the spillways.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51179114)
文摘With the rapid development of high dam projects within China, the dragon-drop-tail spillway tunnel is introduced and widely used. In view of the high water head and the large flow velocity on the dragon-drop-tail section, aerator devices are usually placed for the cavitation damage control. For the device placed in its initial position, it is a serious concern to design a suitable flow regime of the cavity and to control the cavity filling water due to the large flow depth and the low Froude number through this aerator. In this study, the relationships between the geometries of the aerator device and the jet impact angle of the lower trajectory of the flow are theoretically analyzed with/without a local slope. Nine test cases with different geometries are designed, the effectiveness of the filling water control is experimentally investigated under different operation conditions, and two criteria of the local slope design are proposed. It is concluded that the cavity flow regime and the filling water can be improved if a small impact angle and some suitable geometries of the local slope are designed.
基金Project supported by the National Natural Science Foun-dation of China(Grant No.51479057)the PAPD(Grant No.3014-SYS1401)
文摘A new kind of ski-jump-step spillway was reported. By means of the effects of the aeration basin, it supplies the sufficient aeration flow from the first step for stepped chutes, especially for large unit discharge. The physical model experiments demonstrated that, this spillway makes a far better hydraulic performance as regards energy dissipation and cavitation damage protection than the current and conventional stepped spillways, and the unit discharge can be enlarged from about 50 m3/s-60 m3/s.m to 118 m3/s.m in order to significantly reduce the width of the spillways.
