突扩式水跃共轭水深的直接解及验证  

A Direct Solution and Verification of the Conjugated Depth of Hydraulic Jump in Abruptly Expanding Channel

作　　者：宁利中[1] 宁碧波[2] 渠亚伟 田伟利[3] NING Lizhong;NING Bibo;QU Yawei;TIAN Weili(State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology,Xi'an 710048, China;College of Civil Engineering and Architecture, Jiaxing University, Jiaxing, Zhejiang 314001,China;Department of Architecture, Shanghai University, Shanghai 200444, China)

机构地区：[1]西安理工大学省部共建西北旱区生态水利国家重点实验室,西安710048 [2]嘉兴学院建筑工程学院,浙江嘉兴314001 [3]上海大学建筑系,上海200444

出　　处：《西北水电》2020年第4期47-51,共5页Northwest Hydropower

基　　金：国家自然科学基金项目(10872164);西北旱区生态水利国家重点实验室基金项目(2017ZZKT-2)。

摘　　要：由于泄水建筑物下游的地形条件,突扩散水跃被广泛地应用于泄水建筑物下游消能防冲设计。文章建立了突扩水跃方程并用实验验证了它的直接解。在分析水跃段水流形态的基础上对突扩式水跃始端端墙断面压力作出假设,认为回流平均压力是水跃跃首压力、水跃跃末端压力及水跃扩散比的函数。然后,根据动量原理推导出突扩式水跃共轭水深的水跃方程。通过实验给出了回流水深计算式中有关参数的经验公式。建议了突扩式水跃共轭水深水跃方程的显式直接解。突扩式水跃共轭水深水跃方程的计算结果与实验的对比表明,平均误差为5.564%,具有高的精度;与改进前突扩式水跃共轭水深水跃方程的计算结果对比说明,误差小于5%的实验组次增加了15组,占总实验组次的比例提高了16.5%,计算精度明显提高。而且计算过程简单,因此,可以用于水利水电工程的水力计算。Due to the terrain conditions in downstream of the outlet structure,hydraulic jump in abruptly expanding channel is widely applied to the design of energy dissipation and erosion prevention in downstream of the discharge structure.In this paper,hydraulic jump equation in the sudden expansion channel is established and its direct solution is verified by experiments.On the basis of the analysis of the flow pattern of the water jump,a hypothesis is made to the pressure of the end wall at the beginning in the sudden expansion water jump.It is considered that the mean pressure in back-flow region is a function of the pressure of the section before water jump,the pressure of the section after water jump and the abruptly expanding ratio.Then,according to the momentum principle,the hydraulic jump equation of conjugate depth in the sudden expansion channel is derived.The empirical formula for determining parameter in the depth equation in back-flow region is given through experiments.An explicit direct solution of the hydraulic jump equation in abruptly expanding channel is proposed.The comparison of the calculation results of the hydraulic jump equation in the sudden expansion channel and the experiments show that the average error is 5.564%and the accuracy is high.The comparison with the calculation results of the water jump equation before the improvement shows that the experimental group with error of less than 5%increased 15 groups,and the ratio of the experimental group with error of less than 5%to the total experimental group increased by 16.5%,and the calculation accuracy has been obviously improved.In addition,the calculation process is simple.Therefore,it can be used in hydraulic calculation of water conservancy and hydropower projects.

关 键 词：突扩式水跃 直接解 共轭水深 动量方程 

分 类 号：TV135.21[水利工程—水力学及河流动力学]