河床高差对Y型汇流口螺旋流结构的影响  

Effect of bed discordance on helix flow at Y shaped junction

作　　者：王晓刚[1] 严忠民[1] 张幸农[2] 

机构地区：[1]河海大学水利水电工程学院,江苏南京210098 [2]南京水利科学研究院,江苏南京210029

出　　处：《水科学进展》2008年第6期828-834,共7页Advances in Water Science

基　　金：国家自然科学基金资助项目(30490235)~~

摘　　要：通过三维数值模拟分析了河床高差(定义为干支流河床高程差与尾水位之比)对Y型汇流口螺旋流结构的影响。通常情况下,Y型汇流口水流为表面汇聚的双螺旋流。河床高差的存在将减小干流侧水流的螺旋流强度,增强支流侧水流螺旋度,而当支流侧螺旋流很强烈时,干流侧螺旋流将受到破坏。The structure of flow is very complex at Y shaped junction where there are multiform helix flows. This paper analyzes the effect of bed discordance （the ratio of bed discordant height between mainstream and tributary channel to the tailwater depth） on helix flow at Y shaped junction through the three-dimensional numerical simulation. The flow is dominated by two helical cells, usually back-to-back at Y shaped junction. The bed discordance will decrease the intensity of helix flow at the side of mainstream channel and increase it at the side of tributary. When the intensity of helix flow is very strong at the side of tributary, the helix flow will be destroyed at the side of mainstream channel.

关 键 词：河床高差 螺旋流 Y型汇流口 

分 类 号：TV133.2[水利工程—水力学及河流动力学]