Impact of Synthetic Porous Medium Geometric Properties on Solute Transport Using Direct 3D Pore-Scale Simulations

Palma, Paolo Roberto Di; Guyennon, Nicolas; Parmigiani, Andrea; Huber, Christian; Heβe, Falk; Romano, Emanuele

doi:10.1155/2019/6810467

Cited by 6 publications

(3 citation statements)

References 62 publications

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“…The sand‐pack image (Sand Pack LV60C) is obtained from the Imperial College image repository (Imperial College Consortium on Pore‐scale Imaging and Modelling, 2014). It is a compact packing of irregular quartz grains of variable size that is a proxy of sub‐surface aquifers (Di Palma et al., 2019). The different degrees of heterogeneity of the two samples can be quantified in terms of the distribution of flow speeds as discussed in the next section.…”

Section: Methodsmentioning

confidence: 99%

Temporal Evolution of Solute Dispersion in Three‐Dimensional Porous Rocks

Puyguiraud,

Gouze,

Dentz

2024

Water Resources Research

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We study the temporal evolution of solute dispersion in three‐dimensional porous rocks of different heterogeneity and pore structure. To this end, we perform direct numerical simulations of pore‐scale flow and transport in a sand pack, which exhibits mild heterogeneity, and a Berea sandstone, which is characterized by strong heterogeneity as measured by the variance of the logarithm of the flow velocity. The impact of medium structure and pore‐scale mass transfer mechanisms is probed by effective and ensemble dispersion coefficients. The former is a measure for the typical width of a plume, while the latter for the deformation, that is, the spread of a mixing front. Both dispersion coefficients evolve from the molecular diffusion coefficients toward a common finite asymptotic value. Their behavior is governed by the interplay between diffusion, pore‐scale velocity fluctuations and medium structure, which determine the characteristic mass transfer time scales. We find distinctly different dispersion behaviors in the two media, which can be traced back to how particles sample pore‐scale velocity variability and how this depends on the medium structure. These are key elements for the upscaling of transport, mixing and reaction from the pore to the continuum scale.

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Section: Methodsmentioning

confidence: 99%

Temporal Evolution of Solute Dispersion in Three‐Dimensional Porous Rocks

Puyguiraud,

Gouze,

Dentz

2024

Water Resources Research

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“…Such variations in the flow field directly control the magnitude of hydrodynamic dispersion (Bear, 1972; Macdonald et al., 1979; Scheidegger, 1954). Various studies since the 1960s (Bachmat, 1965; Bear & Bachmat, 1967; Fried & Combarnous, 1971; Salles et al., 1993; Yao et al., 1997), including laboratory and field‐scale experiments and, more recently, computational modeling at pore scale (Babaei & Joekar‐Niasar, 2016; Bijeljic et al., 2004; Bouquain et al., 2012; Di Palma et al., 2019; Gouze et al., 2021; Maier et al., 2000; Mousavi Nezhad et al., 2019; Sole‐Mari et al., 2022; Woods, 2014) find the hydrodynamic dispersion coefficient to be power‐law dependent on flow rate with values of exponent between 1 and 1.65. Despite numerous experimental and theoretical studies, a fundamental understanding of how pore structure controls hydrodynamic dispersion and, thus, the flow‐rate dependence of power‐law exponent remains to be explored (Bijeljic and Blunt, 2006, 2007; Di Palma et al., 2019; Gouze et al., 2021; Sole‐Mari et al., 2022).…”

Section: Introductionmentioning

confidence: 99%

Intrapore Geometry and Flow Rate Controls on the Transition of Non‐Fickian to Fickian Dispersion

Singh

Wang

2023

Water Resources Research

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Hydraulic heterogeneity leads to non‐Fickian transport characteristics, which cannot be entirely accounted for by the continuum‐scale advection‐dispersion equation. In this pore‐scale computational study, we investigate the combined effects of flow rate (i.e., Peclet number, Pe) and first‐order hydraulic heterogeneity, that is, resulting from intrapore geometry exclusively, on the transition from non‐Fickian to Fickian dispersion. A set of intrapore geometries is designed and quantified by a dimensionless pore geometry factor (β), which accounts for a broad range of pore shapes likely found in nature. Navier‐Stokes and Advection‐Diffusion equations are solved numerically to study the transport phenomenon using velocity variance, residence time distribution, and coefficients of hydrodynamic dispersion and dispersivity. We determine the length scale (i.e., the linear distance in flow direction) for each pore shape and Pe when non‐Fickian features transition to the Fickian transport regime by incrementally extending the length, that is, the linear array of pores. We show how velocity distribution and variance (σ2) depend on β, and directly control the transition to Fickian dispersion. Pores with a larger β, that is, complex pore shapes with constricted pore‐body or with “slit‐type” attributes, result in a substantial non‐Fickian characteristics. The magnitude of non‐Fickian characteristics gets amplified with an increase in Pe requiring a significantly longer length scale, that is, up to 1 m or a linear array of 500 pores to transition to the Fickian transport regime. We find the hydrodynamic dispersion coefficient (Dh) exponentially depends on the pore shape factor β, with its exponent dependent on flow rate or Pe. We determine constitutive relations to quantify how σ2, β, and Pe, contribute to the degree of non‐Fickian characteristics, the length scale needed for the transition to Fickian transport regime, asymptotic Dh, and the length‐scale dependence of longitudinal dispersivity.

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“…Atualmente é possível criar wormholes em laboratório em amostras com tamanho capaz de caber em equipamentos de tomografia computadorizada ou de IRM pré-clinica. Estudos de DFC em meios porosos utilizam a tomografia computadorizada como base para a informação estrutural (43)(44)(45)(46). Entretanto, para os meios porosos, a IRM é uma técnica de imagem alternativa capaz de utilizar sinal do próton de hidrogênio caso as amostras estejam saturadas com água.…”

Section: Wormholesunclassified

Integração de imagens por ressonância magnética na dinâmica dos fluidos computacional: aplicações em petrofísica e neurociência

Solcia

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Computational fluid dynamics (CFD) is widely used to study the flow of fluids in complex systems. Magnetic resonance imaging (MRI) is a consolidated technique in clinical routine and in applications in medicine. However, despite MRI being able to provide diverse information for simulations, combining CFD and MRI is still a challenge. The objective of this thesis is to develop and apply MRI and CFD in a petrophysics and a neuroscience problem. For the petrophysics study, we used MRI of wormholes in carbonatic rocks obtained in a pre-clinical magnet. For the neuroscience study, we used angiography and perfusion data from cerebral arteries of healthy subjects and subjects with moyamoya disease. Both data were acquired in clinical systems. The processing and simulation approaches were different for each problem. To study the wormholes we used image processing and three-dimensional reconstruction algorithms to generate models and then calculated the simulations in the OpenFOAM software. For the study of cerebral arteries, we used the software SimVascular to generate models and calculate the simulations. Specifically for subjects with moyamoya disease, we compared velocity data acquired by MRI with the simulations through images generated by the Paraview software with the resample filter and a python script. The results of the simulations in wormholes were compared with experimental pressure measurements and were within the experimental deviation and the mesh independence analysis, despite some exceptions. The results of the simulations in cerebral arteries were compared with the perfusion division. The perfusion division is better correlated with the healthy subject than with the subjects with moyamoya disease. In future studies with wormholes, transient and multiphase applications can be considered. For cerebral arteries, it is still necessary to develop new outlet boundary conditions and consider the use of selective perfusion acquisitions. In addition, the simulations translated into resample images used in the analysis of subjects with moyamoya disease can help in the development of MRI techniques. The contribution of this study was to establish the basis for more complex simulations and to define MRI as an essential complement for CFD.

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Impact of Synthetic Porous Medium Geometric Properties on Solute Transport Using Direct 3D Pore-Scale Simulations

Cited by 6 publications

References 62 publications

Temporal Evolution of Solute Dispersion in Three‐Dimensional Porous Rocks

Temporal Evolution of Solute Dispersion in Three‐Dimensional Porous Rocks

Intrapore Geometry and Flow Rate Controls on the Transition of Non‐Fickian to Fickian Dispersion

Integração de imagens por ressonância magnética na dinâmica dos fluidos computacional: aplicações em petrofísica e neurociência

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