Similar articles

Abstract: flow properties of soils can impact a wide range of geotechnical, agricultural, and geophysical processes. Few studies focus on the physical understanding of how pore characteristics can affect flow properties in soils. In this paper, pore network modeling is utilized to investigate intrinsic permeability, water pressure distributions, flow patterns, and critical flow paths in soils with pores varying in size, connectivity, and anisotropy. The results show that increased mean diameter, decreased standard deviation, and increased coordination number of the pores can lead to an increase in intrinsic permeability in soils. Non-uniform water pressure and flow rate distribution will more likely occur in soils with a larger pore size variability. A higher coordination number mitigates the pressure localization but slightly exacerbates non-uniform flow. With the increase in the coefficient of variation (COV) of pore diameters, the percolation path becomes more tortuous and carries more flow. When COV increases from 0 (homogeneous) to 1 (large pore size variability), the tortuosity increases from 1.00 to ~1.71 and the flux carried by the percolation path in soils increases from 2.0% to 7.8%. Pronounced preferential flows may take place in soils with uniformly distributed pore sizes, in which the percolation path can carry as much as 9.2% of the total flux. The anisotropy in pore throat sizes also increases the flow tortuosity and the fraction of flux carried by the percolation path. The permeability anisotropy K_h/K_v increases linearly as the pore throat size anisotropy μ_dh/μ_dv increases logarithmically. These results provide insight for designing soil barriers for either uniform flows or exacerbated preferential flow for fast transport.

It is a well-structured paper evaluating important aspects related to pore network modeling. The english is written according to scientific publication. The authors clearly presented their main objects and methodology.

孔隙特征对土体内部流动特性的影响--孔隙尺度的数值研究

[1]Agrawal DL, Cook NGW, Myer LR, 1991. The effect of percolating structures on the petrophysical properties of Berea sandstone. Proceedings of the 32nd U.S. Symposium on Rock Mechanics, p.345-354.

[2]Ahrens J, Geveci B, Law C, 2005. ParaView: an end-user tool for large-data visualization. In: Hansen CD, Johnson CR (Eds.), Visualization Handbook. Elsevier, Amsterdam, the Netherlands, p.1-17.

[3]Al-Kharusi AS, Blunt MJ, 2008. Multiphase flow predictions from carbonate pore space images using extracted network models. Water Resources Research, 44(6):W06S01.

[4]Allaire SE, Roulier S, Cessna AJ, 2009. Quantifying preferential flow in soils: a review of different techniques. Journal of Hydrology, 378(1-2):179-204.

[5]Allaire-Leung SE, Gupta SC, Moncrief JF, 2000. Water and solute movement in soil as influenced by macropore characteristics: 1. Macropore continuity. Journal of Contaminant Hydrology, 41(3-4):283-301.

[6]Ambegaokar V, Halperin BI, Langer JS, 1971. Hopping conductivity in disordered systems. Physical Review B, 4(8):2612-2620.

[7]Andreini MS, Steenhuis TS, 1990. Preferential paths of flow under conventional and conservation tillage. Geoderma, 46(1-3):85-102.

[8]Berkowitz B, Balberg I, 1993. Percolation theory and its application to groundwater hydrology. Water Resources Research, 29(4):775-794.

[9]Bernabé Y, Bruderer C, 1998. Effect of the variance of pore size distribution on the transport properties of heterogeneous networks. Journal of Geophysical Research: Solid Earth, 103(B1):513-525.

[10]Bianchi M, Zheng CM, Tick GR, et al., 2011. Investigation of small-scale preferential flow with a forced-gradient tracer test. Groundwater, 49(4):503-514.

[11]Blunt MJ, 2017. Multiphase Flow in Permeable Media: a Pore-scale Perspective. Cambridge University Press, Cambridge, UK, p.56-69.

[12]Blunt MJ, Bijeljic B, Dong H, et al., 2013. Pore-scale imaging and modelling. Advances in Water Resources, 51:197-216.

[13]Bultreys T, van Hoorebeke L, Cnudde V, 2015. Multi-scale, micro-computed tomography-based pore network models to simulate drainage in heterogeneous rocks. Advances in Water Resources, 78:36-49.

[14]Bultreys T, de Boever W, Cnudde V, 2016. Imaging and image-based fluid transport modeling at the pore scale in geological materials: a practical introduction to the current state-of-the-art. Earth-Science Reviews, 155:93-128.

[15]Bultreys T, Lin QY, Gao Y, et al., 2018. Validation of model predictions of pore-scale fluid distributions during two-phase flow. Physical Review E, 97(5):053104.

[16]Dai S, Santamarina JC, 2013. Water retention curve for hydrate-bearing sediments. Geophysical Research Letters, 40(21):5637-5641.

[17]David C, 1993. Geometry of flow paths for fluid transport in rocks. Journal of Geophysical Research: Solid Earth, 98(B7):12267-12278.

[18]Dong H, Blunt MJ, 2009. Pore-network extraction from micro-computerized-tomography images. Physical Review E, 80(3):036307.

[19]Fatt I, 1956. The network model of porous media. Petroleum Transactions, 207:144-181.

[20]Flury M, Flühler H, 1994. Brilliant blue FCF as a dye tracer for solute transport studies—a toxicological overview. Journal of Environmental Quality, 23(5):1108-1112.

[21]Friedman SP, Seaton NA, 1998. Critical path analysis of the relationship between permeability and electrical conductivity of three-dimensional pore networks. Water Resources Research, 34(7):1703-1710.

[22]Gerke HH, 2006. Preferential flow descriptions for structured soils. Journal of Plant Nutrition and Soil Science, 169(3):382-400.

[23]Gerke HH, van Genuchten MT, 1996. Macroscopic representation of structural geometry for simulating water and solute movement in dual-porosity media. Advances in Water Resources, 19(6):343-357.

[24]Ghanbarian B, Hunt AG, Ewing RP, et al., 2014. Theoretical relationship between saturated hydraulic conductivity and air permeability under dry conditions: continuum percolation theory. Vadose Zone Journal, 13(8).

[25]Ghanbarian B, Daigle H, Hunt AG, et al., 2015. Gas and solute diffusion in partially saturated porous media: percolation theory and effective medium approximation compared with lattice Boltzmann simulations. Journal of Geophysical Research: Solid Earth, 120(1):182-190.

[26]Ghodrati M, Chendorain M, Chang YJ, 1999. Characterization of macropore flow mechanisms in soil by means of a split macropore column. Soil Science Society of America Journal, 63(5):1093-1101.

[27]Gostick J, Ioannidis M, Fowler M, et al., 2007. Pore network modeling of fibrous gas diffusion layers for polymer electrolyte membrane fuel cells. Journal of Power Sources, 173(1):277-290.

[28]Gostick J, Aghighi M, Hinebaugh J, et al., 2016. OpenPNM: a pore network modeling package. Computing in Science & Engineering, 18(4):60-74.

[29]Hirashima H, Yamaguchi S, Katsushima T, 2014. A multi-dimensional water transport model to reproduce preferential flow in the snowpack. Cold Regions Science and Technology, 108:80-90.

[30]Hunt A, Ghanbarian B, Saville K, 2013. Unsaturated hydraulic conductivity modeling for porous media with two fractal regimes. Geoderma, 207-208:268-278.

[31]Hunt A, Ewing R, Ghanbarian B, 2014. Percolation Theory for Flow in Porous Media, 3rd Edition. Springer, New York, USA, p.46-55.

[32]Hwang SI, Powers SE, 2003. Using particle-size distribution models to estimate soil hydraulic properties. Soil Science Society of America Journal, 67(4):1103-1112.

[33]Jang J, Narsilio GA, Santamarina JC, 2011. Hydraulic conductivity in spatially varying media—a pore-scale investigation. Geophysical Journal International, 184(3):1167-1179.

[34]Kim S, Santamarina JC, 2015. Reactive fluid flow in CO₂ storage reservoirs: a 2-D pore network model study. Greenhouse Gases: Science and Technology, 5(4):462-473.

[35]Kosugi K, 1996. Lognormal distribution model for unsaturated soil hydraulic properties. Water Resources Research, 32(9):2697-2703.

[36]Kosugi K, 1999. General model for unsaturated hydraulic conductivity for soils with lognormal pore-size distribution. Soil Science Society of America Journal, 63(2):270-277.

[37]Laner D, Crest M, Scharff H, et al., 2012. A review of approaches for the long-term management of municipal solid waste landfills. Waste Management, 32(3):498-512.

[38]Li YC, Tong X, Chen Y, et al., 2018. Non-monotonic piezocone dissipation curves of backfills in a soil-bentonite slurry trench cutoff wall. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 19(4):277-288.

[39]Mahabadi N, Dai S, Seol Y, et al., 2016. The water retention curve and relative permeability for gas production from hydrate-bearing sediments: pore-network model simulation. Geochemistry, Geophysics, Geosystems, 17(8):3099-3110.

[40]Maitland GC, 2000. Oil and gas production. Current Opinion in Colloid & Interface Science, 5(5-6):301-311.

[41]Morrow NR, 1975. The effects of surface roughness on contact: angle with special reference to petroleum recovery. Journal of Canadian Petroleum Technology, 14(4):262-274.

[42]Mu DQ, Liu ZS, Huang C, et al., 2008. Determination of the effective diffusion coefficient in porous media including Knudsen effects. Microfluidics and Nanofluidics, 4(3):257-260.

[43]Ng CWW, Song D, Choi CE, et al., 2017. Impact mechanisms of granular and viscous flows on rigid and flexible barriers. Canadian Geotechnical Journal, 54(2):188-206.

[44]Ng CWW, Choi CE, Koo RCH, et al., 2018. Dry granular flow interaction with dual-barrier systems. Géotechnique, 68(5):386-399.

[45]Öhrström P, Hamed Y, Persson M, et al., 2004. Characterizing unsaturated solute transport by simultaneous use of dye and bromide. Journal of Hydrology, 289(1-4):23-35.

[46]Phadnis HS, Santamarina JC, 2011. Bacteria in sediments: pore size effects. Géotechnique Letters, 1(4):91-93.

[47]Piovesan A, Achille C, Ameloot R, et al., 2019. Pore network model for permeability characterization of three-dimensionally-printed porous materials for passive microfluidics. Physical Review E, 99(3):033107.

[48]Qin CZ, Hassanizadeh SM, 2015. Pore-network modeling of solute transport and biofilm growth in porous media. Transport in Porous Media, 110(3):345-367.

[49]Qin CZ, Hassanizadeh SM, Ebigbo A, 2016. Pore-scale network modeling of microbially induced calcium carbonate precipitation: insight into scale dependence of biogeochemical reaction rates. Water Resources Research, 52(11):8794-8810.

[50]Raoof A, Hassanizadeh SM, 2012. A new formulation for pore-network modeling of two-phase flow. Water Resources Research, 48(1):W01514.

[51]Raoof A, Spiers CJ, Hassanizadeh SM, 2011. Reactive pore scale modeling of porosity and permeability evolution in porous media. AGU Fall Meeting.

[52]Ross PJ, Smettem KRJ, 2000. A simple treatment of physical nonequilibrium water flow in soils. Soil Science Society of America Journal, 64(6):1926-1930.

[53]Sahimi M, 1993. Flow phenomena in rocks: from continuum models to fractals, percolation, cellular automata, and simulated annealing. Reviews of Modern Physics, 65(4):1393-1534.

[54]Scanziani A, Singh K, Bultreys T, et al., 2018. In situ characterization of immiscible three-phase flow at the pore scale for a water-wet carbonate rock. Advances in Water Resources, 121:446-455.

[55]Shao W, Bogaard TA, Bakker M, et al., 2015. Quantification of the influence of preferential flow on slope stability using a numerical modelling approach. Hydrology and Earth System Sciences, 19(5):2197-2212.

[56]Šimůnek J, Jarvis NJ, van Genuchten MT, et al., 2003. Review and comparison of models for describing non-equilibrium and preferential flow and transport in the vadose zone. Journal of Hydrology, 272(1-4):14-35.

[57]Singh K, Menke H, Andrew M, et al., 2017. Dynamics of snap-off and pore-filling events during two-phase fluid flow in permeable media. Scientific Reports, 7(1):5192.

[58]Sun X, Luo H, Soga K, 2018. A coupled thermal–hydraulic– mechanical–chemical (THMC) model for methane hydrate bearing sediments using COMSOL Multiphysics. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 19(8):600-623.

[59]Tuli A, Kosugi K, Hopmans JW, 2001. Simultaneous scaling of soil water retention and unsaturated hydraulic conductivity functions assuming lognormal pore-size distribution. Advances in Water Resources, 24(6):677-688.

[60]van Dijk B, 2018. Design of suction foundations. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 19(8):579-599.

[61]van Genuchten MT, 1980. A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Science Society of America Journal, 44(5):892-898.

[62]Wang JQ, Zhao JF, Yang MJ, et al., 2015. Permeability of laboratory-formed porous media containing methane hydrate: observations using X-ray computed tomography and simulations with pore network models. Fuel, 145: 170-179.

[63]Weiler M, Flühler H, 2004. Inferring flow types from dye patterns in macroporous soils. Geoderma, 120(1-2):137-153.

[64]Wu R, Zhu X, Liao Q, et al., 2010. Determination of oxygen effective diffusivity in porous gas diffusion layer using a three-dimensional pore network model. Electrochimica Acta, 55(24):7394-7403.

[65]Xiong QR, Baychev TG, Jivkov AP, 2016. Review of pore network modelling of porous media: experimental characterisations, network constructions and applications to reactive transport. Journal of Contaminant Hydrology, 192:101-117.

[66]Yan Z, Wang YZ, Yang ZX, et al., 2018. A strength degradation model of saturated soft clay and its application in caisson breakwater. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 19(8):650-662.

[67]Zhan LT, Xu H, Chen YM, et al., 2017a. Biochemical, hydrological and mechanical behaviors of high food waste content MSW landfill: preliminary findings from a large-scale experiment. Waste Management, 63:27-40.

[68]Zhan LT, Li GY, Jiao WG, et al., 2017b. Field measurements of water storage capacity in a loess–gravel capillary barrier cover using rainfall simulation tests. Canadian Geotechnical Journal, 54(11):1523-1536.