明渠水流流层平均流速分布规律及其应用  

Vertical Distribution of Horizontal Mean Velocity and Its Application in Open Channels Flow

作　　者：韩金旭[1] 蔡大应[1] 李敬茹[2] 杜凯[1] 李昭悦[1] 

机构地区：[1]黄河水利科学研究院,郑州450003 [2]黄河勘测规划设计有限公司,郑州450003

出　　处：《中国农村水利水电》2015年第6期116-119,128,共5页China Rural Water and Hydropower

基　　金：国家重点基础研究发展计划(2011CB40330305);"十二五"国家科技计划课题(2012BAB02B0403;2012BAD08B05-2)

摘　　要：为提高灌区用水管理水平及水资源利用效率,基于室内及田间实测资料,利用指数律计算了流层平均流速,采用双幂律拟合流层平均流速垂向分布,给出了相关参数的确定方法,并基于流层平均流速分布双幂律提出了"水面流速法"实现明渠测流。经室内及田间实测资料验证,双幂律可以准确表达流层平均流速垂向分布特点,在0.1≤y/h≤0.95的范围内,除个别点外,双幂律计算流速与实测流速的相对误差在±5%以内;首次提出的"水面流速法"只需测量水面中点流速及水位,即可根据断面参数计算渠道流量,测流结果精度较高。与传统方法相比,"水面流速法"无需改造渠道,不干扰水流,在不降低测流精度的条件下,大大节省了田间测流工作量,适应灌区对量水自动化与信息化的发展需求,可以在生产实际中推广应用。In order to optimize water management and water use efficiency in irrigation district ,horizontal velocity distribution char‐acteristics was analyzed in open channels flow ,based on the indoor and field experiment .The characteristic velocity of the flow layer was calculated by the exponential law .In addition ,for the vertical distribution of the horizontal mean velocity ,the two-power law was established ,and the method for defining the parameters was given .And then the surface velocity method was put forward for flow measurement ,based on the two-power law .The results showed that the predicted velocity distribution by the two power law a‐greed with the experimental data in the 0 .1~0 .95 dimensionless depth so well ,and the relative error was as small as ± 5% .In order to calculate the open channel flow ,only the surface middle point velocity and the depth of the cross section were measured in the sur‐face velocity method ,without flow disturbance and transformation of the open channel .Especially ,the workload of the flow meas‐urement by the surface velocity method was substantially reduced .

关 键 词：明渠 流层平均流速 双幂律 水面流速法 量水 

分 类 号：S274.4[农业科学—农业水土工程]