大扩散比闸下折冲水流偏折特性试验研究  

Experimental Research on the Flow Deflection Features Downstream of a Sluice with Large Expansion Ratios

作　　者：陈月君 傅宗甫[2] 陈青生[2] 赵连军[1] 谈广鸣[3] CHEN Yue-jun;FU Zong-fu;CHEN Qing-sheng;ZHAO Lian-jun;TAN Guang-ming(Key Laboratory of Lower Yellow River Channel and Estuary Regulation,Ministry of Water Resources,Yellow River Institute of Hydraulic Research,Zhengzhou 450003,China;College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China;State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China)

机构地区：[1]黄河水利委员会黄河水利科学研究院水利部黄河下游河道与河口治理重点实验室,郑州450003 [2]河海大学水利水电学院,南京210098 [3]武汉大学水资源与水电工程科学国家重点实验室,武汉430072

出　　处：《中国农村水利水电》2022年第4期92-99,共8页China Rural Water and Hydropower

基　　金：“十三五”国家重点研发计划项目(2017YFC0405204);黄河水利科学研究院科技发展基金项目(黄科发202103)。

摘　　要：折冲水流作为闸下常见不良流态之一,会对下游河床和河岸造成严重的冲刷破坏。基于结构对称的大扩散比多孔水闸模型试验,在对称来流和出流条件下,采用LSPIV技术采集下游表面流场数据,研究扩散比和弗劳德数对闸下折冲水流表面流场偏折特性的影响。结果表明,下游河道横断面流速呈“S”型分布,折冲水流动力轴线沿程偏折显著,并按折冲水流区域主控因子的不同将其划分为三个流段,整体上,随着弗劳德数的增大,水闸过流宽度的主控流段趋于缩小,而边界扩展宽度的主控流段趋于扩大。通过回归分析得到折冲水流偏折率是弗劳德数和扩散比的函数,且在一定范围内,偏折率随两个自变量的增加而增大,最大偏折角度不超过20°,该成果对进一步提出闸下不良水流流态改善措施具有指导意义。Deflected flow,as one of undesirable flow patterns,may scour river beds and banks seriously. Experiments are conducted at a symmetric multi-gate sluice model with different large expansion ratios and Froude numbers. The LSPIV(Large-Scale Particle Image Velocimetry)technique is adopted to collect the velocity data of free surface downstream. This study aims at the flow deflection features on the condition of symmetric inflow and outflow. The results show that the velocity distribution at the cross sections display an‘S’shape. The flow dynamic axis is deflected obviously. It is classified into three reaches according to the differences of the dominant factors on the whole deflected flow zone. In general,as Froude number increases,the reach dominated by the total outflow width tends to shrink,while the reach influenced by the enlarged boundary width downstream tends to expand. The deflected ratio of flow is a function of Froude number and expansion ratio by the method of regression analysis,and the deflected ratio increases with Froude number and expansion ratio within limits. The maximum of deflected angle is less than20°. These achievements are instructive to putting forward the improvement measures of undesirable flow patterns.

关 键 词：大扩散比 折冲水流 偏折率 水流动力轴线 LSPIV 

分 类 号：TV135[水利工程—水力学及河流动力学]