摘要
本文通过试验分析，对设置在高坎宽顶堰上的阶梯坝面消能工的水流特性进行了系统研究，并与无阶梯溢流坝作比较后认为：在阶梯溢流坝面上形成的滑掠水流流态，使泄流水舌表面充分掺气，底缘形成含气漩滚。掺气后的水深和流速沿程保持稳定，可大量消散泄流动能，改善坝址下游的水力条件。设置于溢流坝面的阶梯是一种有效的消能工，并具有一定的防空蚀作用。阶梯消能的效果，与下泄单宽流量、坝高、台阶高度、溢流坝面斜率及堰面上滑掠水流的流程长度有关。
The hydraulic characteristics of stepped dissipation on the spillway face with ahigh sill broad一crested weir are sys tematicaIIy studied by experiment. From comparisonwith the conventional spillway,it is seen that skimming flow formed on the steppedspillway face makes a full entrainment of air into the discharge,and the horizontal axisvortices with much air are developed on the stepped face。The depth and velocitv of aer。ated flow are almost unchanged along the flow course,Agreat amount of flOw energycan be dissipated by the stepped spillway.Hence,the hydraulic conditions in thedownstream can be greatly improved.The periment resuIts show that the steps located onspillway face are an effective dissipator and cavitation of the spillway can be preventedto some exent.The effciency of this energy dissipator depends on weir height,unitdischarge, step height and step number,as well as spillway face slope and the skimmingflow length along the stepped spillway face。
基金
云南省应用基础研究基金
关键词
阶梯溢流坝
水流特性
消能工
水力模型
溢流坝
Stepped spillway, Type of broad一crest weir, H ydraulic characteristic,Energy dissipation,Hydraudic model test
