摘要
针对天然河流交汇区域复杂的地形条件及水流运动特性,采用水气两相流三维数值模型,对长江与嘉陵江交汇区水流运动进行深入研究,分析了交汇区域分离区、剪切层、流速场及螺旋度的变化特性。研究结果表明:长江与嘉陵江交汇的水流分离区形状受地形影响明显,随着水位的增加向右岸移动,剪切层整体呈一个扭曲的曲面;干支流原有的环流在交汇之后重新汇合,左岸未出现明显的环流,右岸逆时针的环流有减弱趋势,交汇区域纵向流速呈现高速与低速带分布特征。此外,长江和嘉陵江在交汇口下游螺旋度呈现左侧为负、右侧为正的对称分布,水流结构表现出逐渐形成双螺旋流的趋势,其中左侧的螺旋流逆时针运动,右侧的螺旋流顺时针运动。
Concerning the complexity in flow characteristics and riverbed variations at the confluence region of natural river, a three-dimensional, numerical model of two phase flow is developed to explore the hydrodynamic characteristics of confluence flow between Yangtze River and Jialing River. The investigation focuses on the character- istics of separation zone, shear layer, flow velocity field, and helicity under the complex boundary and topography conditions. The results indicate that the pattern of separation zone is heavily influenced by the topography, tends to shift to the right-side of the river with the increasing of water level, and the shape of shear layer formulates a distort- ed, curved surface. Upon entering the confluence zone, all original secondary vortexes join together and present the tendency of moving to the right side of the channel; while the strength of the secondary flows tends to weaken on the right bank. In addition, two main helix flows are observed and captured at the confluence zone between Yangtze River and Jialing River.
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2015年第3期372-377,共6页
Advances in Water Science
基金
国家自然科学基金资助项目(41171016)~~
关键词
天然河流
干支流交汇
数值模拟
剪切层
螺旋度
natural river
channel confluence
numerical simulation
shear layer
helicity
