保水堰体型参数对过流能力影响的数值模拟  

Numerical simulation of the influence of water keeping weir body type parameter on flow capacity

作　　者：薛海 潘从辉 池映华 刘培 XUE Hai;PAN Conghui;CHI Yinghua;LIU Pei(School of Water Conservancy,North China University of Water Resources and Electric Power,Zhengzhou 450046,China)

机构地区：[1]华北水利水电大学水利学院,郑州450046

出　　处：《南水北调与水利科技（中英文）》2023年第5期1021-1029,共9页South-to-North Water Transfers and Water Science & Technology

基　　金：国家自然科学基金重点项目(41930643)。

摘　　要：保水堰是一种新型溢流堰结构形式,为提升保水堰在大型调水工程中的输水能力,利用实测数据进行模型验证,在确保模拟保水堰堰内水流流态规律准确性的前提下,探究工程中保水堰体型参数对输水系统过流能力的影响。研究揭示了堰井段环状旋涡区的产生与发展机理,并对11种降低堰高方案进行数值计算,分析堰井段流速矢量分布和环状旋涡区范围及能量耗散的变化,发现使输水系统过流能力增加的最佳堰高区间为[1.0 P_(1)≥P≥0.7P_(1)](P为保水堰堰高;P_(1)为堰前堰高)。当堰高在此区间内,通过降低P使堰前流速矢量仰角和堰后环状旋涡区变小,能量耗散显著降低,降低0.1P_(1),流量平均增加2.1%。考虑到工程改造成本和过流能力提升效果,故在本研究提出最佳堰高区间内修改保水堰的结构,为输水系统过流能力提升提供参考。Water keeping weir is a new type of overflow weir,characterized by small pressure in two sections of the transmission line,and simple hydraulic control.In order to enhance the water conveyance capacity of water keeping weir in large water diversion projects.First of all,based on the actual operation of the project,the RNG k-εturbulent flow model is used to close the control equations and establish a three-dimensional isometric numerical simulation model of the water keeping weir,and the simulated head and flow velocity of the pressure measuring tube are in good agreement with the measured data,and on the premise of ensuring the accuracy of the flow pattern in the simulated water keeping weir,the influence of the water keeping weir body parameters on the over-flow capacity of the box culvert-water keeping weir water conveyance system is investigated.It revealed the mechanism of the generation and development of annular vortex zones in the weir section,and determined that the dispersion of high velocity water flow zone caused by the height of the water keeping weir and the presence of annular vortex zones are the main bottlenecks affecting the improvement of flow capacity.Thus,the proposed solution of reducing the height of the water keeping weir concentrate the high velocity water flow zone and reduce the scope of the annular vortex zone to reduce the energy dissipation in the weir section,so as to achieve the purpose of improving the overflow capacity of the water conveyance system.Numerical calculations were carried out for 11 options of reducing the weir height of water keeping weirs,and the flow velocity vector distribution and the extent of the annular vortex zone in the weir section as well as the variation of turbulent kinetic energy dissipation and overflow flow were analyzed.The results show that the overflow of the water conveyance system can be enhanced by the weir reduction scheme,and by compared between different weir height schemes,the optimal weir height interval that increases its overflow capacit

关 键 词：保水堰 数值模拟 过流能力提升 环状旋涡区 

分 类 号：TV672[水利工程—水利水电工程]