常密度与变密度流体双组分溶质运移实验研究  

Experimental study on dual-components solutes transport influids with constant and variable densities

作　　者：叶逾 刘森 蔡芳敏 鲁春辉 谢一凡 徐腾 YE Yu;LIU Sen;CAI Fangmin;LU Chunhui;XIE Yifan;XU Teng(College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China;The National Key Laboratory of Water Disaster Prevention,Hohai University,Nanjing 210098,China;Fujian Provincial Investigation,Design&Research Institute of Water Conservancy&Hydropower Co.,Ltd.,Fuzhou 350000,China;Yangtze Institute for Conservation and Development,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水利水电学院,江苏南京210098 [2]河海大学水灾害防御全国重点实验室,江苏南京210098 [3]福建省水利水电勘测设计研究院有限公司,福建福州350000 [4]河海大学长江保护与绿色发展研究院,江苏南京210098

出　　处：《水利学报》2023年第9期1080-1086,共7页Journal of Hydraulic Engineering

基　　金：国家重点研发计划项目(2021YFC3200500);中央高校基本科研业务费项目(B220202060)。

摘　　要：为准确预测地下水系统中污染物的运移路径及浓度分布,需深入理解不同密度条件下多组分溶质的稀释及运移机理。本文通过室内实验,分别在常密度流体与变密度流体中,系统观测了荧光素钠与氯化钠两种化合物在不同混合比时的运移现象,量化了出口处的浓度分布、稀释指数及两种溶质的浓度标准差。研究发现:在常密度流体中,两种化合物的运移相互独立,其浓度分布取决于化合物各自的水动力扩散与弥散;而在变密度流体中,两种溶质的运移相互影响,其运移轨迹与浓度分布均相同,取决于占比较大化合物的运移结果;变密度对流导致溶质羽和周围流体的接触面积增大,相较于常密度条件,溶质的稀释程度得到大幅提升。In order to accurately predict the migration path and concentration distributions of contaminants in groundwater system,it is necessary to understand the dilution and transport of multi-component solutes under different density conditions.In this study,transport phenomena of fluorescein and sodium chloride in the solution with different mixing ratios are observed,and concentration distributions,dilution index and concentration standard deviation between two solutes are quantified at the outlet.The results show that in constant density fluids two compounds are transported independently,and the concentration distributions are determined by the compound-specific diffusivities and dispersivities.In contrast,in variable density fluids,two solutes interact each other.The transport trajectory and the concentration distributions are identical between the two solutes and they are dependent on the solute with larger proportion in the mixture.Compared to the constant density condition,variable density convection leads to a larger contact area between the solute plume and the surrounding fluids,thus remarkably enhancing solute dilution.

关 键 词：变密度流体 常密度流体 双组分 溶质运移 室内实验 

分 类 号：TV138[水利工程—水力学及河流动力学]