Drainage dynamics controlled by corner flow: Application of the foam drainage equation
Drainage dynamics controlled by corner flow: Application of the foam drainage equation
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DOI：
10.1002/2016wr019477
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发表时间：
2016-10
影响因子：
5.4
通讯作者：
F. Hoogland;P. Lehmann;D. Or
中科院分区：
文献类型：
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作者：
F. Hoogland;P. Lehmann;D. Or
在快速排水过程中，水被保留在前面，定义了植物可用水和非饱和区的水力特性。在这项研究中，我们表明，泡沫排水方程（FDE）可以应用于预测宏观排水动力学后面的前面，因为网络的液体通道控制的泡沫和裂缝的孔隙空间中的液体流动。为了预测达西尺度下的排水率，在将通道几何形状和边界条件适应于实验条件后，对FDE进行数值求解。FDE的结果是在很好的协议与实测流量背后的排水前在粗和细砂。一个值得注意的例外是从细砂中快速排水，其中饱和孔群在前缘通过后持续存在，并且与FDE预测相比排水更快。与FDE公式的良好一致性所暗示的角落毛细流动的主导地位，可以提高非饱和导水率函数的科学基础，并提供了一个更现实的观点，胶体和病原体在非饱和介质中传输的路径的几何形状。
In fast drainage processes water is retained behind the front, defining the plant available water and hydraulic properties of the unsaturated region. In this study we show that the foam drainage equation (FDE) can be applied to predict macroscopic drainage dynamics behind the front because a network of liquid channels controls the liquid flow in both foams and crevices of the pore space. To predict drainage rates at the Darcy scale the FDE is solved numerically after adapting channel geometries and boundary conditions to experimental conditions. The FDE results were in good agreement with measured flow rates behind a drainage front in coarse and fine sand. A notable exception was rapid drainage from fine sand where saturated pore clusters persisted after front passage and drained faster compared to FDE predictions. The dominance of corner capillary flows implied by the good agreement with the FDE formulation could improve the scientific underpinning of the unsaturated hydraulic conductivity function and offers a more realistic view of the geometry of pathways for colloid and pathogen transport in unsaturated media.