Shear Flows Accelerate Mixing Dynamics in Hyporheic Zones and Hillslopes
Shear Flows Accelerate Mixing Dynamics in Hyporheic Zones and Hillslopes
复制标题
剪切流加速了潜流带和山坡的混合动力
DOI：
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发表时间：
2018
影响因子：
5.2
通讯作者：
T. Le Borgne
中科院分区：
文献类型：
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作者：
A. Bandopadhyay;P. Davy;T. Le Borgne
地形起伏和河床形态产生嵌套的流线模式，这驱动了地表水浓度或温度变化在深度的传播和混合。虽然在这种流动池中的浓度分布和微生物化学反应经常在稳态运输条件下进行研究，但越来越多的证据表明，瞬态混合过程可能对有效混合和反应速率有显着贡献。在这里，我们表明，这些流线型的模式作为剪切流，显着加速流动细胞内的混合动力学，并可能导致在深度的瞬态混合热点的形成。我们提供了分析解决方案，量化了流动池中脉冲和前沿初始溶质分布的混合动力学，这代表了自然系统中更复杂溶质分布的两个理想化端元。这些结果提供了新的见解混合的模式和动态在潜流带，山坡，集水区尺度。
Topographic relief and river bedforms generate nested streamline patterns, which drive the propagation and mixing at depth of changes in surface water concentration or temperature. While concentration distributions and biogeochemical reactions in such flow cells are often studied under steady state transport conditions, there is increasing evidence that transient mixing processes may have a significant contribution to effective mixing and reaction rates. Here we show that these streamline patterns act as shear flows, which significantly accelerate mixing dynamics within flow cells and can lead to the formation of transient mixing hot spots at depth. We provide analytical solutions that quantify the dynamics of mixing in a flow cell for a pulse and a front initial solute distribution, which represent two idealized end‐members of more complex solute distributions in natural systems. These results provide new insights into the patterns and dynamics of mixing at hyporheic zone, hillslope, and catchment scales.
影响因子：
5.2
作者：
de Barros, Felipe P. J.;Dentz, Marco;Nowak, Wolfgang
通讯作者：
Nowak, Wolfgang