明渠自由跌水水力特性及其在流量计量上的应用  

Hydraulic characteristics of free fall water in open channels and its application in flow measurement

作　　者：周聪颖 袁磊[1] 张与馨 邵欣[1] 李乃稳[2] ZHOU Congying;YUAN Lei;ZHANG Yuxin;SHAO Xin;LI Naiwen(The Engineering and Technicial College of Chengdu University of Technology,Leshan614000,Sichuan,China;College of Water Resource&Hydropower,Sichuan University,Chengdu610065,Sichuan,China)

机构地区：[1]成都理工大学工程技术学院,四川乐山614000 [2]四川大学水利水电学院,四川成都610065

出　　处：《水利水电技术（中英文）》2024年第5期106-114,共9页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(52379073);四川省高校重点实验室项目(2023QYY06);四川省哲学社会科学重点研究基地项目(SCLY2106);乐山市科技局重点研究项目(A322021011)。

摘　　要：【目的】明渠跌水作为衔接渠道上下游水流的有效设施,可应用于明渠流量计量,通过简单测量跌坎断面水深即可实现渠道流量的精确计量。为研究明渠自由跌水水力特性及其在流量计上的应用,【方法】采用分析对比法将国内外明渠自由跌水的研究成果进行整理,从自由跌水水力特性、跌水量水试验研究及理论研究3个方面进行了对比分析,【结果】发现明渠自由跌水水力特性的研究多集中在跌坎断面压力分布;明渠跌水量水试验研究集中在he/hc的影响因素(渠道底坡S、糙率n、渠道宽度、渠道断面形式、弗劳德数等),该值可基于能量方程、动量方程、N-S方程及其他数值模拟方法得出。【结论】结果表明:试验中he/hc值在矩形渠道中基本是一个常数,但其他断面形式的渠道中该结论未得到验证;该值与明渠底坡S和糙率n有关,底坡方面的研究主要集中在缓坡(S=0.002 6~0.097 3)渠道,陡坡研究较少而平坡研究更少,糙率n的研究范围在0.009 3~0.045 0,但实际工程中n值变化较大。因此有必要在其他形式渠道上对he/hc值做进一步验证,并在更大范围内研究he/hc值与底坡S和糙率n的关系,这样更有利于明渠跌水量水技术的推广和应用。[Objective]As an effective facility for connecting the upstream and downstream water flow of open channels,open channel drop water can be applied to open channel flow measurement.By simply measuring the depth of its drop bucket section,accurate measurement of its flow can be achieved.[Methods]An analysis and comparison method is used to summarize the research result of free fall in open channels both domestically and internationally.The comparative analysis is conducted from three aspects:hydraulic characteristics of free fall in open channels,experimental research on water drop in open channels,and theoretical research,[Results]it was found that the research on the hydraulic characteristics of free falling water in open channels mostly focuses on the pressure distribution at the section of the falling bucket, the research on the water drop test of open chan-nels focuses on the influencing factors (channel bottom slope S, roughness n, channel width, channel section form, Froude num-ber, etc. ), which can be obtained based on energy equation, momentum equation, N-S equation, and other numerical simula-tion method. [Conclusion]The result indicate that the value of he / hc in the experiment is basically a constant in rectangular channels, but this conclusion has not been verified in other cross-sectional forms of channels;this value is related to the bottom slope S and roughness n of the open channel, and research on the bottom slope is mainly focused on gentle slopes (S =0. 002 6 ~0. 097 3) channels, with less research on steep slopes and less on flat slopes. The research range of roughness n is 0. 009 3~ 0. 045 0, but in actual engineering, the value of n varies greatly. Therefore, it is necessary to further verify the values on other forms of channels and study the relationship between the values and the bottom slope S and roughness n on a larger scale, which is more conducive to the promotion and application of open channel drop water technology.

关 键 词：自由跌水 水力特性 流量测定 跌坎水深 临界水深 影响因素 

分 类 号：TV131[水利工程—水力学及河流动力学]