摘要
基于矩形泄槽物理模型试验,研究了泄槽底部设置较为特殊的曲线型边界的三维凸型和凹型掺气坎的掺气水流特性,并将同种条件下传统直线型连续掺气坎的掺气水流特性与之做比较。结果表明:不同体型的掺气坎水力特性及流态有明显的差异。3种体型的掺气坎中,直线型坎掺气空腔长度最大,凸型和凹型掺气坎对增大掺气空腔长度不利;空腔回水深度随着单宽流量的增大而增大,凸型坎有利于减小掺气空腔回水,特别是在较大流量时效果更明显;3种掺气坎掺气空腔后近壁水流掺气浓度沿程均迅速衰减,泄槽底板和边墙的近壁水流掺气浓度分布有所不同,导致泄槽底板的掺气保护长度,直线型掺气坎的最大,凸型坎的次之,凹型坎的最短,但泄槽边墙的掺气保护长度则是凹型坎的最长。凹型掺气坎对保护边墙免遭空蚀破坏、增大边墙的保护范围更有利。研究成果可为应用异型掺气坎的采用提供更多的参考和实验依据。
Based on the hydraulic model experiments,the flow characteristics after the three dimensional convex and concave aerators with curved boundary set on the base plate of the rectangle flume are investigated and are compared with the conventional straight aerator set on the same flume.The results show that the aerated flow characteristics downstream and flow patterns downstreamthe of three kind aerators have obvious differences.The cavity length of the conventional straight aerator is the longest among the three kind aerators.The convex and concave aerators are not good for increasing the cavity length.For the three kind of tested aerators,the depth of back water in the cavity after the aerator increases with the increase of the flow discharge.But the convex aerator is good at reducing the backwater in the cavity after the aerator,especially in big flow discharge.The air concentration in the flow area near the surfaces of the base plate and the side walls of the flume after the aerator decreases rapidly along the flow route for all tested aerators,but the distribution of the air concentration in the flow is different for each aerator,which leads to their own different length of protective segments.For the protective segment length of the base plate of the tested flume,it is the longest for the conventional straight aerator and the shortest for the convex aerator.But for the protective segment length of the side walls of the tested flume,it is the longest for the concave aerator.It shows that the concave aerator maybe good at for protecting side walls of spillway from cavitation erosion in the projects.The research results can provide useful theoretical and experimental evidences for better use of aeration facilities.
作者
游翔升
徐一民
王卿
薛彤
YOU Xiang-sheng;XU Yi-min;WANG Qing;XUE Tong(College of Electric Power Engineering,Kunming University of Science and Technology,Kunming 650500,Yunnan,China)
出处
《中国农村水利水电》
北大核心
2020年第8期231-236,242,共7页
China Rural Water and Hydropower
基金
国家自然科学基金项目(51269005)。
关键词
模型试验
凸型掺气坎
凹型掺气坎
掺气浓度
水力特性
hydraulic model test
convex aerator
concave aerator
air concentration
hydraulic characteristics
作者简介
游翔升(1994-),男,硕士研究生,主要从事工程水力学研究。E-mail:280361838@qq.com;通讯作者:徐一民(1962-),男,博士,教授,研究方向:水力学及河流动力学。E-mail:yiminxu@sina.com。
