A statistical analysis of void size distribution in a simulated narrowly graded packing of spheres

Reboul, Nadège; Vincens, Éric; Cambou, Bernard

doi:10.1007/s10035-008-0111-5

Cited by 88 publications

(87 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…12a, and the nearly constant values of the effective intrinsic permeability k s z over the test duration t, shown in Fig. 12b, confirm the applicability of Darcy's law (1) and that the permeability measurements have taken place in the laminar Darcy regime. The measurement of water flow and pressure difference is captured with a sample frequency of 0.5 Hz.…”

Section: Porosity and Permeabilitysupporting

confidence: 60%

“…Figure 10a shows the permeabilities of the subsets as function of their porosities, for three different theoretical estimates, increasing according to Kozeny-Carman. 1 Figure 10b shows the intrinsic permeabilities normalized by the square of the mean particle diameter, confirming the non-linearly increasing trend of the intrinsic permeability with increasing porosity. The colored data points in Fig.…”

Section: Porosity and Permeabilitysupporting

confidence: 56%

“…The pore throat distribution in granular packings was also theoretically investigated by To et al [50], Jaafar and Likos [3], Reboul et al [1] and Shire et al [51], where the pore throat distribution is estimated from the given particle size distribution of the granular packing. To et al [50] and Reboul et al [1] considered the flow process of suspensions in porous granular packings and therefore the pore throat areas were described by circular voids, which were smaller than the real constrictions sizes. In this study, the fluid flow of water in granular sintered packings were investigated, and thus the identified pore throat areas were replaced by circular voids with same area as shown in Fig.…”

Section: Pore Throat Determinationmentioning

confidence: 99%

See 2 more Smart Citations

Hydraulic properties of porous sintered glass bead systems

et al. 2017

View full text Add to dashboard Cite

In this paper, porous sintered glass bead packings are studied, using X-ray Computed Tomography (XRCT) images at 16 µm voxel resolution, to obtain not only the porosity field, but also other properties like particle sizes, pore throats and the permeability. The influence of the sintering procedure and the original particle size distributions on the microstructure, and thus on the hydraulic properties, is analyzed in detail. The XRCT data are visualized and studied by advanced image filtering and analysis algorithms on to the extracted sub-systems (cubes of different sizes) to determine the correlations between the microstruc- Institute of Applied Mechanics (CE), University of Stuttgart, Pfaffenwaldring 7, 70569 Stuttgart, Germany ture and the measured macroscopic hydraulic parameters. Since accurate permeability measurements are not simple, special focus lies on the experimental set up and procedure, for which a new innovative multi-purpose cell based on a modular concept is presented. Furthermore, segmented voxel-based images (defining the microstructure) are used for 3D (three-dimensional) lattice Boltzmann simulations to directly compute some of the properties in the creeping flow regime. A very good agreement between experimental and numerical porosity and permeability could be achieved, in most cases, validating the numerical model and results. Porosity and permeability gradients along the sample height could be related to gravity acting during sintering. Furthermore, porosity increases in the outer zones of the samples due to the different contact geometry between the beads and the confining cylinder wall during sintering (which is replaced by a membrane during permeability testing to close these pores at the surface of the sample). The influence of different filters on the gray scale distributions and the impact of the segmentation procedure on porosity and permeability is systematically studied. The complex relationships and dependencies between numerically determined permeabilities and hydraulic influence parameters are investigated carefully. In accordance to the well-known Kozeny-Carman model, a similar trend for local permeability values in dependence on porosity and particle diameter is obtained. Other than statistical models, which estimate the pore throat distribution on the basis of the particle size distribution, in this study XRCT scans are used to determine the pore throats in sintered granular systems, which are finally linked to the intrinsic permeability through the lattice Boltzmann simulations. From the μXRCT analysis two distinct peaks in pore throat distributions could be identified, which can be clearly assigned to typical pore throat areas occurring in polydisperse granular systems. Moreover, a linear dependency between average pore throat diameter and porosity as well as between permeability and pore throat diameter is reported. Furthermore, almost identical mean values for porosity and permeability are found from sub-system and full-system REV analysis. For sintered granular...

show abstract

Section: Porosity and Permeabilitysupporting

confidence: 60%

Section: Porosity and Permeabilitysupporting

confidence: 56%

Section: Pore Throat Determinationmentioning

confidence: 99%

See 1 more Smart Citation

Hydraulic properties of porous sintered glass bead systems

et al. 2017

View full text Add to dashboard Cite

show abstract

“…In order to avoid over-segmentation of the void space, adjacent tetrahedra were merged using a criterion proposed by Al-Raoush et al (2003) and Reboul et al (2008). This can be explained by reference to a simple two-dimensional analogy of uniform particles on a square grid, as illustrated in Fig.…”

Section: Analysis Approachmentioning

confidence: 99%

Constriction size distributions of granular filters: a numerical study

Shire¹,

O’Sullivan

2016

Géotechnique

View full text Add to dashboard Cite

The retention capability of granular filters is controlled by the narrow constrictions connecting the voids within the filter. The theoretical justification for empirical filter rules used in practice includes consideration of an idealised soil fabric in which constrictions form between co-planar combinations of spherical filter particles. This idealised fabric has not been confirmed by experimental or numerical observations of real constrictions. This paper reports the results of direct, particle-scale measurement of the constriction size distribution (CSD) within virtual samples of granular filters created using the discrete-element method (DEM). A previously proposed analytical method that predicts the full CSD using inscribed circles to estimate constriction sizes is found to poorly predict the CSD for widely graded filters due to an over-idealisation of the soil fabric. The DEM data generated are used to explore quantitatively the influence of the coefficient of uniformity, particle size distribution and relative density of the filter on the CSD. For a given relative density CSDs form a narrow band of similarly shaped curves when normalised by characteristic filter diameters. This lends support to the practical use of characteristic diameters to assess filter retention capability.

show abstract

“…Only a few studies have presented quantitative characterisations of pore features. Reboul et al (2008) presented a statistical description of pore volumes and inscribed sphere volumes, by implementing the modified Delaunay tessellation introduced by Al-Raoush et al (2003). Kang et al (2013) extended the application of the modified Delaunay tessellation by considering the evolution of pore sizes in the numerical simulation of a direct shear test.…”

Section: Introductionmentioning

confidence: 99%

Pore shapes, volume distribution and orientations in monodisperse granular assemblies

et al. 2015

View full text Add to dashboard Cite

The complex mechanical behaviour of granular materials is commonly studied by considering the evolving particle contact network. An often overlooked feature is the influence of micro-scale geometric configuration of pores on the macroscopic response. This paper presents a series of tools to quantify the shape, volume distribution and orientation characteristics of the pore space. The proposed approach is validated using data from physical and numerical experiments with monodisperse assemblies of spheres. A pore shape parameter is proposed that relates pore volume and surface area, and is analytically related to the void ratio and the number of edges forming the polyhedral pore unit cell. The pore volume distribution is shown to be uniquely described by the analytical k-gamma distribution proposed by Aste and Di Matteo (2008). A pore orientation tensor is introduced to define the principal orientation of individual pore units. This is subsequently used to define a global orientation tensor that reveals an isotropic pore network for the reference monodisperse assemblies. The global orientation tensor is analytically expressed in terms of the parameters defining the pore volume distribution. The pore characteristics described in this paper provide the basis for describing the evolution of the pore space during deformation and its relationship to mechanical properties.

show abstract

A statistical analysis of void size distribution in a simulated narrowly graded packing of spheres

Cited by 88 publications

References 34 publications

Hydraulic properties of porous sintered glass bead systems

Hydraulic properties of porous sintered glass bead systems

Constriction size distributions of granular filters: a numerical study

Pore shapes, volume distribution and orientations in monodisperse granular assemblies

Contact Info

Product

Resources

About