明流脉动压强特性对自掺气发展影响试验研究  

Experimental Study on the Influence of Fluctuating Pressure Characteristics to the Self-Aerated Open Channel Flow Developing Region

作　　者：唐毓朔 邓军[1] 卫望汝[1] 龚静 TANG Yushuo;DENG Jun;WEI Wangru;GONG Jing(State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学水力学与山区河流开发保护国家重点实验室

出　　处：《人民黄河》2019年第6期111-115,共5页Yellow River

基　　金：国家自然科学基金资助项目(51609162);国家重点基础研究发展计划项目(2016YFC0401901)

摘　　要：通过系列模型试验,采用脉动压强仪和针式掺气浓度仪,在不同初始流速与水深条件下详细测量了陡槽自掺气水流沿程各断面掺气浓度与脉动压强,重点分析了脉动压强与掺气浓度分布之间的相关关系,以及断面平均脉动强度对掺气区气泡扩散的影响。试验结果表明:随着明渠水流自掺气沿程不断发展,同一个断面上的脉动压强从断面底部至自由面呈现出先增大后减小的趋势,其中最大值位于断面掺气扩散区;断面平均脉动强度呈现沿程逐渐增大的变化趋势;在不同来流流速、水深及雷诺数条件下,自掺气水流断面平均脉动强度与断面掺气扩散区域之间呈现良好的相关关系。This paper presented an experimental study on fluctuating pressure characteristics of self-aeration developing region in open channel flows and its influence on self-aeration diffusion.In self-aerated developing region of steep open channel,fluctuating pressure and air concentrations were firstly recorded by fluctuating pressure testing device and double-tip conductivity probe for different initial velocities and water depths,and then turbulent intensity influence to the self-aeration in open channel could be investigated.The results show that due to the influence of aeration,the turbulent intensity on cross-section shows a trend of firstly increasing and then decreasing from the bottom of the section to the free surface.The maximum value is located in the middle of the aerated diffusion zone.The analysis believes that the mean turbulent intensity of section gradually increases along steep open channel.For different initial water velocities/water depths and Reynolds numbers,there is a good correlation between self-aeration developing process and mean cross-section turbulent intensity.

关 键 词：明渠 自掺气发展区 掺气浓度 脉动压强 

分 类 号：TV135.2[水利工程—水力学及河流动力学]