Scientific thoughts
Scientific thoughts on unsaturated porous media
Characterization of porous media: from bundle of capillary tubes to pore networks
In 2013, an interesting paper was published in Vadose Zone Journal on the assumptions we widely use and the need to revise them at some stage; one of such conceptual models which is widely used is the so-called bundle of capillary tube which is a building block for many theoretical studies and experimental investigations. For instance we determine in many disciplines the pore size distribution of the material based on this concept when for instance we use MIP method.
In their 2013 paper, Hunt, Ewing and Horton discussed the applicability of this assumption:
Hunt, A. G., R. P. Ewing, and R. Horton (2013), What’s Wrong with Soil Physics?, Soil Sci. Soc. Am. J., 77(6), 1877.
Ryan of Virginia Tech. had discussed this paper in his lab page and I commented therein as well.
One way may be using pore network models to extract pore size distribution but they have also their own parameters which should be found in order to be realistically representative of the medium (if you are going to use them to back calculate pore size distribution for instance from for instance soil water retention curves (capillary pressure-saturation curves)). They give possibilities but further research is needed.
To know more about modeling soil water retention curve and the application of pore network models in this regard, you can refer to:
Rostami, A., Habibagahi, G., Ajdari, M., & Nikooee, E. (2013). Pore network investigation on hysteresis phenomena and influence of stress state on the SWRC. International Journal of Geomechanics, 15(5), 04014072.
To know more about pore network models in general and their application in muti-phase flow in unsaturated medium, the following texts provide an insightful overview:
You may refer to the original paper of Hunt and his colleagues to get more ideas on the conceptual models we currently use in soil physics (in general in unsaturated porous media physics) and the assumptions we currently deal with and how influential they can be.
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