Fluid flow in porous media using image-based modelling to parametrize Richards' equation.
Fluid flow in porous media using image-based modelling to parametrize Richards' equation.
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DOI：
10.1098/rspa.2017.0178
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发表时间：
2017-11
期刊：
影响因子：
--
通讯作者：
Roose T
中科院分区：
文献类型：
--
作者：
Cooper LJ;Daly KR;Hallett PD;Naveed M;Koebernick N;Bengough AG;George TS;Roose T
理查兹方程中的参数通常由试验测得的土-水特征曲线和饱和导水率计算。多孔介质中经常出现的复杂孔隙结构使这种参数化复杂化，这是由于润湿和干燥之间的滞后以及弯曲度的影响。不是从这些间接测量估计理查兹方程中的参数，而是使用基于图像的建模来研究孔结构与参数之间的关系。采用体素分辨率为6 μm的土壤样品的三维X射线计算机断层扫描图像堆栈来创建计算网格。将双流体（在这种情况下为水和空气）的Cahn-Hilliard-Stokes方程应用于该网格，并使用COMSOL Multiphysics中的有限元法求解。然后通过均匀化得到理查兹方程中的放大参数。研究了0°、20°和60°三种不同接触角对土壤-水保持曲线的影响。结果表明，孔结构在很大程度上影响着流体的流动特性，不同的接触角可以改变理查兹方程的参数。
The parameters in Richards' equation are usually calculated from experimentally measured values of the soil–water characteristic curve and saturated hydraulic conductivity. The complex pore structures that often occur in porous media complicate such parametrization due to hysteresis between wetting and drying and the effects of tortuosity. Rather than estimate the parameters in Richards' equation from these indirect measurements, image-based modelling is used to investigate the relationship between the pore structure and the parameters. A three-dimensional, X-ray computed tomography image stack of a soil sample with voxel resolution of 6 μm has been used to create a computational mesh. The Cahn–Hilliard–Stokes equations for two-fluid flow, in this case water and air, were applied to this mesh and solved using the finite-element method in COMSOL Multiphysics. The upscaled parameters in Richards' equation are then obtained via homogenization. The effect on the soil–water retention curve due to three different contact angles, 0°, 20° and 60°, was also investigated. The results show that the pore structure affects the properties of the flow on the large scale, and different contact angles can change the parameters for Richards' equation.
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影响因子：
6.9
作者：
Daly KR;Keyes SD;Masum S;Roose T
通讯作者：
Roose T
影响因子：
2.1
作者：
Lourenco, S. D. N.;Woche, S. K.;Saulick, Y.
通讯作者：
Saulick, Y.
影响因子：
4.2
作者：
McHale, G;Newton, MI;Shirtcliffe, NJ
通讯作者：
Shirtcliffe, NJ
影响因子：
2
作者：
Roose, T;Fowler, AC
通讯作者：
Fowler, AC
影响因子：
4.4
作者：
CAHN, JW;HILLIARD, JE
通讯作者：
HILLIARD, JE