掺气坎组合首级台阶对阶梯溢流坝面的影响  

Effect of combination of aerated hurdle and the first stage step on stepped spillway surface

作　　者：张勤 杨具瑞[1] 汤建青 叶小胜 郭莹莹 ZHANG Qin;YANG Jurui;TANG Jianqing;YE Xiaosheng;GUO Yingying(Faculty of Modern Agricultural Engineering,Kunming University of Science and Technology,Kunming,Yunnan 650500,China)

机构地区：[1]昆明理工大学现代农业工程学院,云南昆明650500

出　　处：《排灌机械工程学报》2019年第3期216-223,共8页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(51569010)

摘　　要：为了避免阶梯溢洪道中前几级阶梯表面发生空蚀破坏,在对阶梯溢洪道的设计中加入掺气坎,形成前置掺气坎式阶梯溢洪道.通过对Y型宽尾墩+阶梯溢流坝+消力池的联合消能工过渡阶梯首级台阶台面取4个角度、前置掺气坎取2个角度共8种组合工况分别进行水工模型试验,改变水库流量,从空腔长度、水面线、负压、底板时均压力、消能率等方面,寻找改善水力特性的过渡台阶衔接体型.结果表明:掺气空腔随着首级阶梯台面角和掺气坎增大,与阶梯坝面分离空间更大,水流挑射更高,空腔更长且工况2的空腔长度均大于工况1的空腔长度;随着掺气坎和首级阶梯台面角增大,溢流坝阶梯面最大负压绝对值减小;消力池底板压力和水面线变化不大,消能率增大.在8个方案中,前置掺气坎角度为10°、首级阶梯台面角度0°时的方案5最优.In order to avoid cavitation damage on surfaces of the first few steps of a stairway spillway,an aerated hurdle was added to the design of stairway spillway to form a pre-mixed culvert spillway.The transition step shape with improved hydraulic characteristics was sought in terms of cavity length,water line,negative pressure,time-averaged pressure on stilling bottom,energy dissipation and so on by changing reservoir flow through experiments on a series of hydraulic models.In these experiments,the first step in the transition step was fell by 0°,5°,10°and 15°,and the pre-aeration angle had 8°,10°two values,the joint energy dissipators with Y-shaped flaring gate piers,stepped spillway and stilling pool were built based on eight combinations of these parameters respectively.The results show that the aerated cavity increases with increasing pre-aerator and first stage angle,the higher the water jet,the larger the space separating from the dam surface and the longer the cavity length.The length of cavity in working condition 2 is longer than in working condition 1;the absolute value of the maximum negative pressure decreases with increasing aerator and first step slope.The pressure and water line are not changed much,and the energy dissipation rate increases.Thus,the fifth case with 10°aerated hurdle angle and 0°first stage step slope is the best combination in eight experimental combinations.

关 键 词：Y型宽尾墩 阶梯溢流坝 首级台阶 掺气坎 

分 类 号：TV135.2[水利工程—水力学及河流动力学] S277.9[农业科学—农业水土工程]