U形渠道水流流速垂向分布规律及模拟  

Vertical distribution of streamwise velocity and its prediction in U-shaped channel

作　　者：杨士红[1] 韩金旭[2] 彭世彰[1] 高晓丽[1] 顾宏[3] 李江安 

机构地区：[1]河海大学水文水资源与水利工程科学国家重点实验室,江苏南京210098 [2]黄河水利科学研究院,河南郑州450003 [3]高邮市水务局,江苏高邮225600

出　　处：《排灌机械工程学报》2012年第3期309-314,共6页Journal of Drainage and Irrigation Machinery Engineering

基　　金：“十二五”国家科技支撑计划项目(2011BAD25B07);黄河水利科学研究院中央级公益性科研院所基本科研业务费专项资金资助项目(HKY-JBYW-2012-15)

摘　　要：为了明确U形渠道水流流速分布规律,指导田间用水管理生产实际,基于室内和田间实测资料,分析了U形渠道水流流速分布特点,将非对称封闭渠道流速分布结果引入明渠水流流速分布研究中,提出了垂向流速分布双幂律,同时给出了相关参数的确定方法,并采用实测资料对双幂律进行了验证.结果表明,U形渠道同一测线不同测点水流流速随着垂向位置的升高而逐渐增大,但在水面处有所减小,最大流速出现在水流表面以下.在此基础上建立的能够同时表达上下底面影响水流流速分布的双幂律,能够准确表达U形渠道水流流速分布特点;与常用流速分布规律相比,双幂律具有更高的计算精度.经实测资料验证,双幂律拟合流速垂向分布计算结果的相对误差较小,在相对深度处于0.10～0.95的计算区间内,双幂律计算相对误差小于5%,且对常见的不同断面、不同规模渠道具有普遍适用性.To find a guide to water management in field irrigation, the vertical distribution of streamwise velocity in a U-shaped open channel was clarified by means of indoor and field experiments. In addition, a two-power law for such a distribution was established by using the law of velocity in asym-metric closed channel. The methods for defining the parameters in the two-power law were given, and then the law was validated by the experimental data. The results showed that the flow velocity was lowered with increasing water depth, but the peak velocity appeared under the free surface. The predicted velocity distribution by the two-power law agreed with the experimental data in the 0.10 -0.95 dimensionless depth so well that the error was as small as 5%, suggesting the law can involve the effect of free surface and channel wall. Compared with the traditional law of velocity distribution, the two-power law is more accurate, and may be used in an open channel with a cross-section of other shape.

关 键 词：U形渠道 水流 流速垂向分布 双幂律 灌区 

分 类 号：S276.7[农业科学—农业水土工程]