Author(s): Mingxiong Cao; Jihong Jiang; Binrui Zhou; Guozheng Cai
Linked Author(s):
Keywords: Rapids; Rock rapids; Hydraulic characteristics; Generalized experiment
Abstract: Based on the topographic features of rock rapids, four sets of generalized topography were designed. The results of the generalized rapids flume experiment indicated the following facts: the velocity and the water level of upstream changed little. Coming to the rapids throat, the former increased streamwisely while the latter decreased sharply; crossing rapids throat, the velocity reached to the maximum and the water level reached to the minimum, then adverse slope emerged in water surface with decreasing velocity. The streamwise variations of velocity and water level presented three dimensional characteristics. Having passed through rapids throat, the mainstream centralized around the midstream, with return flow on both sides, and water surface seemed to be a paraboloid, which was consistent to the prototype on the whole. Rapids states mainly depended on the water surface slope and the velocity, and on how dangerous the flow pattern was as well. These affecting factors were all relevant to rapids’ topographic features, among which the extent to which the protruding points stretched into the river were compressed, and the deflected stream angle of the protruding points were the most important. The survey of the water level and the topography will be directed with the conclusions above, and so will the determinative methods of channel regulation.
Year: 2005