矩形明渠水跃段沿程和局部水头损失的计算  

Calculation of frictional and minor head losses for hydraulic jump section in rectangular open channels

作　　者：张志昌[1] 赵莹[2] 

机构地区：[1]西安理工大学,西安710048 [2]中国电建集团西北勘测设计研究院有限公司工程实验检测公司,西安710065

出　　处：《水力发电学报》2015年第11期88-94,共7页Journal of Hydroelectric Engineering

摘　　要：根据前人对水跃段流速分布、壁面切应力和总水头损失的研究成果,利用紊流边界层理论研究水跃段的沿程水头损失;利用水跃段总水头损失和沿程水头损失的关系,研究水跃段的局部水头损失,并根据局部水头损失的定义研究水跃段的局部阻力系数。研究表明,水跃段的沿程水头损失是跃前断面流速、水跃长度、水流运动粘滞系数的函数;局部水头损失和局部阻力系数是跃前断面共轭水深比和弗劳德数的函数。分析了水跃段总水头与水跃区总水头比值、相对沿程水头损失、相对局部水头损失、局部阻力系数与弗劳德数的关系。结果表明,相对沿程水头损失随着弗劳德数的增大而减小,水跃段总水头损失与水跃区总水头损失的比值、相对局部水头损失、局部阻力系数均随着弗劳德数的增大而增大。A calculation method of frictional head loss in a hydraulic jump section has been developed using turbulent boundary layer theory based on the previous studies of velocity distribution, wall shear stress, and total head loss. Minor head loss is calculated according to the relationship of total loss versus frictional loss, and local resistance coefficient is estimated using the definition of minor loss. Results show that the frictional loss is a function of the velocity distribution on the initial cross section, the length of hydraulic jump, and the kinematic viscosity of water while the minor loss and resistance coefficient a function of conjugate depth ratio and the Froude number at the initial cross section. The analysis includes relationships of the total head ratio of hydraulic jump section over jump area, relative frictional loss, relative minor loss, and local resistance coefficient versus the Froude number. It shows that among these four parameters, the relative frictional loss decreases with the Froude number while the other three increase with it.

关 键 词：矩形明渠 水跃段 边界层 水头损失 阻力系数 

分 类 号：TV133[水利工程—水力学及河流动力学]