床面形态渗透率对潜流交换特性的影响  

Experimental investigation on the impact of bedform permeability on hyporheic exchange characteristics

作　　者：赵亮[1,2] 王学勇 王岱峰 樊靖郁 ZHAO Liang;WANG Xueyong;WANG Daifeng;FAN Jingyu(School of Mechanics and Engineering Science,Shanghai University,Shanghai 200444,China;Shanghai Institute of Applied Mathematics and Mechanics,Shanghai University,Shanghai 200072,China)

机构地区：[1]上海大学力学与工程科学学院,上海200444 [2]上海大学上海市应用数学和力学研究所,上海200072

出　　处：《上海大学学报（自然科学版）》2023年第6期1104-1114,共11页Journal of Shanghai University:Natural Science Edition

基　　金：国家自然科学基金资助项目(11472168)。

摘　　要：为了研究床面形态物理特性对潜流交换的影响,通过环形水槽实验,采用概化的2维离散床面形态研究了床面形态组成单元的渗透率与潜流交换通量之间的定量关联和变化特征,并分析了床面形态组成单元的渗透率变化对有效扩散系数的影响.实验结果表明,床面形态组成单元的渗透率变化对潜流交换起着不可忽视的作用.在该实验参数变化范围内,床面形态的存在引入了附加的泵吸交换,而泵吸交换对潜流交换通量的相对贡献与床面形态组成单元的渗透率变化密切相关,当其渗透率相对较低时泵吸交换和湍流渗透均趋于减弱,与平整底床相比其有效扩散系数总体上呈不同程度的减小趋势.The influence of bedform physical properties on the hyporheic exchange pro-cess was assessed by investigating the quantitative correlation and variation between the permeability of bedform elements and hyporheic exchangeflux.This investigation was conducted using laboratory annularflume experiments and conceptual two-dimensional discrete bedforms.Based on the results,it was observed that bedform permeability has a significant impact on the hyporheic exchange process.Within the bounds of the experimen-tal parameters,the presence of bedforms was found to introduce an additional pumping exchange.The contribution of this pumping exchange to the overall hyporheic exchangeflux was found to be closely related to the permeability variation in the bedform elements.When the permeability of these elements was low,the pumping exchange and turbulence penetration decreased,leading to an overall reduction in the effective diffusion coefficient when compared to scenarios with aflat bed.

关 键 词：潜流交换 床面形态 渗透率 有效扩散系数 

分 类 号：O352[理学—流体力学]