摘要
河道中冰盖显著改变了水流流动结构。采用k-ε紊流模型建立了冰盖下水流流动垂向二维数值模型;根据量纲分析理论提出了流速分布规律的影响因素;针对各种因素的不同组合进行了数值计算,并对其流动特性如最大流速点位置、冰区及床面区平均流速等进行了分析研究;对冬季封冻河道的二点测流法精度进行了理论分析。研究结果表明,冰盖下水流的纵向流速在流动核心区并不遵循对数分布规律,同时揭示了冰盖底部与河床的相对粗糙比、河床相对粗糙度及雷诺数对流速分布规律的影响。
The presence of an ice-cover in a river will significantly change flow structure. The vertical two-dimensional numerical model for ice-covered flow is developed by the κ-ε turbulence model. Based upon the theory of dimensional analysis the factors influencing the velocity distribution patterns are proposed. The numerical experiments for various combinations of factors are conducted, and the flow characteristics such as location of the maximum velocity, mean velocities of obth ice-affected region and bed-diffected region are analyzed. The accuracy of two-point depth-averaged flow measurement for ice-covered fiver is investigated.The results reveal that the sectional velocity distribution deviates from the logarithmic law in the core flow area. Meanwhile, the influence of roughness ratio of ice-cover bottom to bed, bed relative roughness and Reynold number on velocity distribution pattern is indicated.
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2006年第2期209-215,共7页
Advances in Water Science
基金
国家自然科学基金资助项目(50579030)
清华大学基础研究基金(JC2002006)~~
关键词
封冻河道
流速分布规律
紊流模型
数值计算
流动特性
freeze-up river
velocity distribution
turbulence model
numerical simulation
flow structure
