保水堰后增加明槽段对水体进气及水流流态的影响  

The Impact of Adding Short Open Channel after Weir Well on Air Input of the Water Body and the Flow Pattern

作　　者：戴熙武 盛雨[2] 

机构地区：[1]河海大学水利水电学院,南京210098 [2]江苏第二师范学院数学与信息技术学院,南京210098

出　　处：《中国农村水利水电》2017年第5期73-76,共4页China Rural Water and Hydropower

摘　　要：针对长距离分段低压输水系统中堰井后带明槽段与不带明槽段两种输水单元,采用VOF模型(Volume of Fluid model)进行二维数值模拟,研究分析两种输水单元保水堰流量系数、堰后水体进气量、气泡运动规律及下游有压箱涵流速分布状态等。结果表明:堰后增加明槽段基本不影响保水堰的流量系数及堰后水体的进气量,堰后水体进气量随淹没度减小而增大;增加明槽段能显著减少气体进入下游有压箱涵,能限制堰后旋滚向下游有压箱涵发展,并且能调整堰后底部主流使之平顺的进入下游箱涵,使下游箱涵中水流流速分布更加均匀。For two kinds of water supply units with short open channel and without short open channel after the weir well in the long-distance stepped low-pressure water supply system, the 2D numerical simulation method with Volume of Fluid model is used to study and analyze the flow coefficient of water-retaining weirs, the air input of the water body after the weir well, bubble motion, the flow pattern of the downstream pressure box culvert and so on. The results show that, with short open channel added after weir wells, it hardly affects the flow coefficient of water-retaining weir and air input of the water body after weir wells. The air input increases with the decrease in the submerged criterion. With the short open channel added after the weir well, it will remarkably reduce the quantity of air entering into the downstream pressure box cul- vert, prevent the surface vortex in the weir wall from developing into the downstream pressure box culvert effectively, and it can also contrib- ute to the adjustment for the bottom mainstream. Thus, it flows into the downstream pressure box culvert smoothly, and then, the flow velocity distribution in the downstream pressure box culvert will be more uniform.

关 键 词：明槽段 VOF模型 数值模拟 气泡运动 流速分布 

分 类 号：TV13[水利工程—水力学及河流动力学]