Nonlocal Interface Dynamics and Pattern Formation in Gravity-Driven Unsaturated Flow through Porous Media
Nonlocal Interface Dynamics and Pattern Formation in Gravity-Driven Unsaturated Flow through Porous Media
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DOI：
10.1103/physrevlett.101.244504
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发表时间：
2008-12-12
影响因子：
8.6
通讯作者：
Juanes, Ruben
中科院分区：
文献类型：
--
作者：
Cueto-Felgueroso, Luis;Juanes, Ruben
多孔介质中多相流的现有连续介质模型无法解释为什么在渗透到均匀干燥土壤的过程中会发生优先流（指状流动）。按照相场方法，我们提出了一个连续体模型，该模型解释了润湿前沿的表观表面张力，并且不引入新的独立参数。该模型再现了指状流的观察到的特征，特别是指状尖端的水饱和度较高，这被认为对于指状流的形成至关重要。从线性稳定性分析中，我们预测指速度和指宽度都随着渗透率的增加而增加，并且预测与实验在定量上一致。
Existing continuum models of multiphase flow in porous media are unable to explain why preferential flow (fingering) occurs during infiltration into homogeneous, dry soil. Following a phase-field methodology, we propose a continuum model that accounts for an apparent surface tension at the wetting front and does not introduce new independent parameters. The model reproduces the observed features of fingered flows, in particular, the higher saturation of water at the tip of the fingers, which is believed to be essential for the formation of fingers. From a linear stability analysis, we predict that finger velocity and finger width both increase with infiltration rate, and the predictions are in quantitative agreement with experiments.