过渡区动床明渠流的流速分布  

Velocity profile of open-channel flows in the transitional roughness region on mobile beds

作　　者：刘春晶[1] 李丹勋[1] 曲兆松[1] 王兴奎[1] 

机构地区：[1]清华大学水沙科学教育部重点实验室,北京100084

出　　处：《水科学进展》2006年第1期49-54,共6页Advances in Water Science

基　　金：国家自然科学基金资助项目(50279013;50221903)~~

摘　　要：利用激光流速仪测量了随水流强度加大松散床面,从定床到具有一定输沙强度的动床流动,试验水流条件均处于过渡区。试验资料分析表明,动床过渡区明渠流的卡门常数小于通常所采用的0.4;水流强度逐渐增大,随着推移质运动量增加,阻力系数有减小再增大的趋势;雷诺应力分布和紊动强度分布规律同光滑明渠流类似。The experiments on open-channel flows on the rough mobile bed in the transitional region are reported in this paper. The velocity in the flume were measured by a 2-D LDA, and the resistance coefficient were calculated with the Einstein＇ s resistance division method. The experimental results show that （1） The Karman constant in the Log-law of the open channel flows in the transition region is smaller than which that of the smooth open channel flows, and the integral parameter B does not coincide well with the Nikuradse＇s result from the pipe flows; （2） The weak bed load in the flume may cause the drag-reducing effect; and （3） The Reynolds stress and the turbulence distribution are similar to those in the smooth open channel flows.

关 键 词：明渠流 过渡粗糙区 动床 推移质 流速分布 

分 类 号：TV142.2[水利工程—水力学及河流动力学] TV143.1