粗糙透水床面明渠水流的垂线流速分布  

Velocity profile of turbulent open-channel flows over rough and permeable beds

作　　者：陈兴伟[1,2] 林木生[1] 程年生 林炳青[1] 

机构地区：[1]福建师范大学地理科学学院,福建福州350007 [2]湿润亚热带山地生态国家重点实验室培育基地,福建福州350007 [3]School of Civil and Environmental Engineering,Nanyang Technological University

出　　处：《水科学进展》2013年第6期849-854,共6页Advances in Water Science

基　　金：国家自然科学基金资助项目(50979015)~~

摘　　要：为了进一步揭示粗糙透水床面明渠水流运动特性，针对垂线流速分布研究存在的问题，根据边界层理论，推导了含有摩阻流速、理论床面流速和原点位移等3个参数的修正对数公式；通过水槽试验，运用激光多普勒测速仪，分别对用直径1cm玻璃珠构成的粗糙不透水和透水床面明渠水流的垂线流速分布进行了测量。结果表明：推导的修正对数公式与实测符合很好；相同水流条件下，透水床面的摩阻流速要大于不透水床面，各自的阻力系数保持基本不变；理论床面流速是主流平均流速的0．35—0．45倍，且床面相对流速随着雷诺数的增大而略有减小。The time-mean velocity profile of turbulent open-channel flows over rough and permeable beds is analyzed both experimentally and theoretically in this study. The velocity profile can be derived from a slip velocity at the bed surface and an origin displacement, a modified logarithmic law is thus obtained. The experiment is conducted in a glass-sided flume where the channel bed is prepared with uniform marbles 1 cm in diameter. The velocity is measured using a laser doppler veloeimeter. The profile of the measured velocity is used to validate the theoretically derived pro- file. The resuh shows that the modified logarithmic law is able to well describe the measured velocity profile. Under the same flow condition, the shear velocity over the permeable bed would be greater than that over the impermeable bed. The value of the flow at the permeable interface is about 0.35 to 0.45 times that of the average stream flow.

关 键 词：垂线流速分布 对数公式 透水床面 明渠水流 

分 类 号：TV133.1[水利工程—水力学及河流动力学]