梯形输水明渠的线流速分布特征  

Line-velocity distribution in trapezoidal open channel

作　　者：蔡勤 刘敦利 马立平 王志刚[3] 胡鹤鸣[4] CAI Qin;LIU Dunli;MA Liping;WANG Zhigang;HU Heming(Xinjiang Uygur Autonomous Region Research Institute of Measurement&Testing,Urumqi 830011,China;Xinjiang Water Conservancy Development Investment(Group)Co.,Ltd,Urumqi 830009,China;China Institute of Water Resources and Hydropower Research,Beijing 100038,China;National Institute of Metrology,Beijing 100029,China)

机构地区：[1]新疆计量测试研究院,新疆乌鲁木齐830011 [2]新疆水利发展投资(集团)有限公司,新疆乌鲁木齐830009 [3]中国水利水电科学研究院,北京100038 [4]中国计量科学研究院,北京100029

出　　处：《工业计量》2024年第6期109-112,共4页Industrial Metrology

基　　金：国家重点研发计划课题(2017YFC0405705);新疆计量测试研究院科研项目(XJL2023KY002)。

摘　　要：线流速是进行流量计算的重要基础。为分析梯形渠道断面线流速的分布特征,以某顶宽27 m、底宽6 m、坡度角为21.80°的标准梯形断面为例,采用一套交叉10声道布置的超声测流装置,对渠道不同典型高程处的线流速进行了测试。结果表明:交叉两个声道面上相同声道高度的线流速在0.6H以下区域较为一致,H为水位总高,水流稳定,各高度线流速变化一致性较好,而0.6H以上区域水流横向流动明显,线流速差异性较大,流速代表性相对较差;渠道断面上的线流速随着高度的增加逐渐增大,两者近似指数关系;最大线流速的位置与断面平均流速有关,当断面平均流速较低时,最大线流速位于0.8H处,当断面平均流速较高时,最大线流速出现于水面附近;渠道断面平均流速值与位于0.35H~0.37H区域的线流速值相当。研究成果可为梯形断面渠道流量测量中代表性线流速位置的选取和流量测量方案的制定提供技术参考。Line-velocity is an important foundation for flow computation.In order to analyze the line-velocity distribution of trapezoidal open channel,a typical standard channel was selected.It enjoyed a top width of 27 m and a bottom width of 6 m,with the slope angle of 21.80°.Besides,a 10-path ultrasonic line-velocity measuring device was employed with symmetrical crossed paths arrangement to measure the line-velocities at typical heights.The tested results showed that the line-velocities measured by the two crossed paths at the same typical height agreed with each other well when the height was smaller than 0.6H,indicating that the flow was stable and consistency of line-velocities varying with the height was good.By comparison,for the area above 0.6H,the line-velocity differences between the two crossed paths got larger and the representativeness was relatively poor due to lateral flows.And in general,the line-velocities increased approximately exponentially gradually with the increasing height.However,the height of the maximum line-velocity depended on the average velocity of the whole cross section.It could take the value of 0.8H for relatively small cross-sectional average velocities while it should be H for large ones.In addition,the cross-sectional average velocities actually corresponded to the line-velocities at 0.35H~0.37H.These results can provide technical supports to the selection of representative line-velocities and plan making for the flow measurement.

关 键 词：计量学 流量计量 梯形明渠 线流速分布 多声道超声测流装置 

分 类 号：TV133[水利工程—水力学及河流动力学]