Unified molecular dynamics and homogenization analysis for bentonite behavior: current results and future possibilities

Ichikawa, Yasuaki; Kawamura, Katsuyuki; Nakano, Miki; Kitayama, Kazumi; Kawamura, Hideki

doi:10.1016/s0013-7952(99)00058-7

Cited by 66 publications

(39 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, the pore space comprised only intergranular porosity with no nanoporosity such as encountered in clays. Ichikawa et al (1999Ichikawa et al ( , 2001Ichikawa et al ( , 2004a and Wang et al (2003) employed the Homogenization of Periodic Media to model fluid flow through clays. The microscopic and the macroscopic fluid flow equations were obtained from the Navier-Stokes equations using double scale asymptotic expansions, the two levels of description being related by the macroscopic permeability.…”

Section: Multiscale Modelling Of Fluid Flow In Geomaterialsmentioning

confidence: 99%

“…With respect to existing works on compacted bentonites (Bouchelaghem and Jozja, 2009a,b;Ichikawa et al, 1999Ichikawa et al, , 2001Ichikawa et al, , 2004aWang et al, 2003) which are all based on simplified microstructures (Poiseuille-like flow for lamellae of hydrated montmorillonite, symmetrical arrangements of spherical or cylindrical grains on the mesoscopic scale), the macroscopic permeability tensor is computed on real microstructures, while both mesopores and non-smectite grains are taken into account, leading to new effective permeability formulations. According to Baltean (1999) and Wodie (1992), the effective permeability will be obtained on the macroscopic scale by upscaling from the mesoscopic scale alone, consisting here of the arrangement of clay aggregates, inter-aggregate voids and non-smectite grains.…”

Section: Modelling Approach and Outline Of The Papermentioning

confidence: 99%

“…The derivation of the effective fluid flow behaviour through periodic media has been detailed in previous works for the case of constant fluid viscosity (Baltean et al, 2003;Baltean, 1999;Ichikawa et al, 1999Ichikawa et al, , 2001Levy, 1987;Wodie, 1992). For random media, the homogenization procedure is similar to the homogenization of periodic media, provided that the assumption of periodicity is replaced by the assumption of local statistical homogeneity and ergodicity (Rubinstein and Torquato, 1989;Torquato, 2005).…”

Section: Mesoscopic Description Of the Domain Occupied By Clay Aggregmentioning

confidence: 99%

“…Fluid viscosity µ = µ(y ′ ) is taken to vary locally in the microstructure, in order to account for the "ice sheet" effect of viscosity increase near the particle surface (Ichikawa et al, 1999(Ichikawa et al, , 2001(Ichikawa et al, , 2004aPusch and Yong, 2006). The mesoscopic description of flow in clay particles is obtained by performing an asymptotic analysis in terms of the parameter ε ′ (Bensoussan et al, 1978;Levy, 1987;Sanchez-Palencia, 1980;Rubinstein and Torquato, 1989), leading to (Bouchelaghem and Jozja, 2009a):…”

Section: Mesoscopic Description Of the Domain Occupied By Clay Aggregmentioning

confidence: 99%

See 3 more Smart Citations

Fluid flow and effective conductivity calculations on numerical images of bentonite microstructure

Bouchelaghem

Pusch

2017

Applied Clay Science

View full text Add to dashboard Cite

Hydraulic conductivities of compacted water-saturated bentonite were computed based on the real microstructure. The Homogenization of Periodic Media approach employed fully acknowledges the heterogeneous and multiscale microstructure of clay, as well as locally varying physical flow properties. Consequently, three levels of description were considered : the microscopic level of clay particles, the mesoscopic level of clay aggregates, mineral grains and inter-aggregate porosity, and the macroscopic level of the sample subjected to fluid pressure gradients in the laboratory. Starting from the local description of fluid flow, the expression of the effective hydraulic conductivity tensor was derived. The soft and dense gels and the open voids may form a connected flow path or remain occluded. The local problems were solved on the microstructure obtained from a digitalized micrograph by image analysis. The contribution to macroscopic flow by the soft and dense gels was investigated in various configurations, and comparisons were made with hydraulic conductivity data for MX-80 bentonite.

show abstract

Section: Multiscale Modelling Of Fluid Flow In Geomaterialsmentioning

confidence: 99%

Section: Modelling Approach and Outline Of The Papermentioning

confidence: 99%

Section: Mesoscopic Description Of the Domain Occupied By Clay Aggregmentioning

confidence: 99%

Section: Mesoscopic Description Of the Domain Occupied By Clay Aggregmentioning

confidence: 99%

See 2 more Smart Citations

Fluid flow and effective conductivity calculations on numerical images of bentonite microstructure

Bouchelaghem

Pusch

2017

Applied Clay Science

View full text Add to dashboard Cite

show abstract

“…3. Snap shot for clay-water system and the dif fusivity distribution [6]. In this sense we use a unit cell as shown in Fig.…”

Section: Fe Procedures For Ha Diffusion Problemmentioning

confidence: 99%

Micro-structure of Bentonite Clay and Diffusion Coefficient Given by Multiscale Homogenization Analysis

Fujii

Ichikawa

Kawamura

et al. 2003

Journal of the Society of Materials Science, Japan

View full text Add to dashboard Cite

Bentonite consists of nanometer scale of smectitic clay minerals (mainly montmorillonite) and micrometer scale of macro-grains (mainly quatz). Properties of saturated bentonite are characterized by hydrated clay minerals. For a diffusion problem in bentonite we developed a new multiscale homogenization analysis (HA) procedure which relates microscale characteristics with a macroscopic behavior.We discuss diffusion properties of tritium water (HTO) compared with experimental data. Microscopic properties of the montmorillonite hydrate such as diffusivity of chemical species which are used in HA are determined by a molecular dynamics (MD) simulation method. We show the calculated results are consistent with macroscale experimental data.

show abstract

Numerical solutions for flow in porous media

Wang

Leung

Chow

2003

Num Anal Meth Geomechanics

View full text Add to dashboard Cite

SUMMARYA numerical approach is proposed to model the flow in porous media using homogenization theory. The proposed concept involves the analyses of micro-true flow at pore-level and macro-seepage flow at macrolevel. Macro-seepage and microscopic characteristic flow equations are first derived from the NavierStokes equation at low Reynolds number through a two-scale homogenization method. This homogenization method adopts an asymptotic expansion of velocity and pressure through the microstructures of porous media. A slightly compressible condition is introduced to express the characteristic flow through only characteristic velocity. This characteristic flow is then numerically solved using a penalty FEM scheme. Reduced integration technique is introduced for the volumetric term to avoid mesh locking. Finally, the numerical model is examined using two sets of permeability test data on clay and one set of permeability test data on sand. The numerical predictions agree well with the experimental data if constraint water film is considered for clay and two-dimensional cross-connection effect is included for sand.

show abstract

Unified molecular dynamics and homogenization analysis for bentonite behavior: current results and future possibilities

Cited by 66 publications

References 2 publications

Fluid flow and effective conductivity calculations on numerical images of bentonite microstructure

Fluid flow and effective conductivity calculations on numerical images of bentonite microstructure

Micro-structure of Bentonite Clay and Diffusion Coefficient Given by Multiscale Homogenization Analysis

Numerical solutions for flow in porous media

Contact Info

Product

Resources

About