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Intercomparison Of 3d Pore Scale Flow And Solute Transport Simulation Methods
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Book Synopsis Intercomparison of 3D Pore-scale Flow and Solute Transport Simulation Methods by :
Download or read book Intercomparison of 3D Pore-scale Flow and Solute Transport Simulation Methods written by and published by . This book was released on 2015 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiple numerical approaches have been developed to simulate porous media fluid flow and solute transport at the pore scale. These include 1) methods that explicitly model the three-dimensional geometry of pore spaces and 2) methods that conceptualize the pore space as a topologically consistent set of stylized pore bodies and pore throats. In previous work we validated a model of the first type, using computational fluid dynamics (CFD) codes employing a standard finite volume method (FVM), against magnetic resonance velocimetry (MRV) measurements of pore-scale velocities. Here we expand that validation to include additional models of the first type based on the lattice Boltzmann method (LBM) and smoothed particle hydrodynamics (SPH), as well as a model of the second type, a pore-network model (PNM). The PNM approach used in the current study was recently improved and demonstrated to accurately simulate solute transport in a two-dimensional experiment. While the PNM approach is computationally much less demanding than direct numerical simulation methods, the effect of conceptualizing complex three-dimensional pore geometries on solute transport in the manner of PNMs has not been fully determined. We apply all four approaches (FVM-based CFD, LBM, SPH and PNM) to simulate pore-scale velocity distributions and (for capable codes) nonreactive solute transport, and intercompare the model results. Comparisons are drawn both in terms of macroscopic variables (e.g., permeability, solute breakthrough curves) and microscopic variables (e.g., local velocities and concentrations). Generally good agreement was achieved among the various approaches, but some differences were observed depending on the model context. The intercomparison work was challenging because of variable capabilities of the codes, and inspired some code enhancements to allow consistent comparison of flow and transport simulations across the full suite of methods. This paper provides support for confidence in a variety of pore-scale modeling methods and motivates further development and application of pore-scale simulation methods.
Book Synopsis Modeling Single-phase Flow and Solute Transport Across Scales by : Yashar Mehmani
Download or read book Modeling Single-phase Flow and Solute Transport Across Scales written by Yashar Mehmani and published by . This book was released on 2014 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow and transport phenomena in the subsurface often span a wide range of length (nanometers to kilometers) and time (nanoseconds to years) scales, and frequently arise in applications of CO2 sequestration, pollutant transport, and near-well acid stimulation. Reliable field-scale predictions depend on our predictive capacity at each individual scale as well as our ability to accurately propagate information across scales. Pore-scale modeling (coupled with experiments) has assumed an important role in improving our fundamental understanding at the small scale, and is frequently used to inform/guide modeling efforts at larger scales. Among the various methods, there often exists a trade-off between computational efficiency/simplicity and accuracy. While high-resolution methods are very accurate, they are computationally limited to relatively small domains. Since macroscopic properties of a porous medium are statistically representative only when sample sizes are sufficiently large, simple and efficient pore-scale methods are more attractive. In this work, two Eulerian pore-network models for simulating single-phase flow and solute transport are developed. The models focus on capturing two key pore-level mechanisms: a) partial mixing within pores (large void volumes), and b) shear dispersion within throats (narrow constrictions connecting the pores), which are shown to have a substantial impact on transverse and longitudinal dispersion coefficients at the macro scale. The models are verified with high-resolution pore-scale methods and validated against micromodel experiments as well as experimental data from the literature. Studies regarding the significance of different pore-level mixing assumptions (perfect mixing vs. partial mixing) in disordered media, as well as the predictive capacity of network modeling as a whole for ordered media are conducted. A mortar domain decomposition framework is additionally developed, under which efficient and accurate simulations on even larger and highly heterogeneous pore-scale domains are feasible. The mortar methods are verified and parallel scalability is demonstrated. It is shown that they can be used as "hybrid" methods for coupling localized pore-scale inclusions to a surrounding continuum (when insufficient scale separation exists). The framework further permits multi-model simulations within the same computational domain. An application of the methods studying "emergent" behavior during calcite precipitation in the context of geologic CO2 sequestration is provided.
Book Synopsis Multiphase Flow in Permeable Media by : Martin J. Blunt
Download or read book Multiphase Flow in Permeable Media written by Martin J. Blunt and published by Cambridge University Press. This book was released on 2017-02-16 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a fundamental description of multiphase fluid flow through porous rock, based on understanding movement at the pore, or microscopic, scale.
Download or read book PEM Fuel Cells written by Jasna Jankovic and published by Walter de Gruyter GmbH & Co KG. This book was released on 2023-05-22 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive introduction to the rapidly developing field of modeling and characterization of PEM fuel cells. It focuses on i) fuel cell performance modeling and performance characterization applicable from single cells to stacks, ii) fundamental and advanced techniques for structural and compositional characterization of fuel cell components and iii) electrocatalyst design. Written by experts in this field, this book is an invaluable tool for graduate students and professionals.
Book Synopsis Pore-scale and Continuum Simulations of Solute Transport Micromodel Benchmark Experiments by :
Download or read book Pore-scale and Continuum Simulations of Solute Transport Micromodel Benchmark Experiments written by and published by . This book was released on 2014 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Four sets of nonreactive solute transport experiments were conducted with micromodels. Three experiments with one variable, i.e., flow velocity, grain diameter, pore-aspect ratio, and flow-focusing heterogeneity were in each set. The data sets were offered to pore-scale modeling groups to test their numerical simulators. Each set consisted of two learning experiments, for which our results were made available, and one challenge experiment, for which only the experimental description and base input parameters were provided. The experimental results showed a nonlinear dependence of the transverse dispersion coefficient on the Peclet number, a negligible effect of the pore-aspect ratio on transverse mixing, and considerably enhanced mixing due to flow focusing. Five pore-scale models and one continuum-scale model were used to simulate the experiments. Of the pore-scale models, two used a pore-network (PN) method, two others are based on a lattice Boltzmann (LB) approach, and one used a computational fluid dynamics (CFD) technique. Furthermore, we used the learning experiments, by the PN models, to modify the standard perfect mixing approach in pore bodies into approaches to simulate the observed incomplete mixing. The LB and CFD models used the learning experiments to appropriately discretize the spatial grid representations. For the continuum modeling, the required dispersivity input values were estimated based on published nonlinear relations between transverse dispersion coefficients and Peclet number. Comparisons between experimental and numerical results for the four challenge experiments show that all pore-scale models were all able to satisfactorily simulate the experiments. The continuum model underestimated the required dispersivity values, resulting in reduced dispersion. The PN models were able to complete the simulations in a few minutes, whereas the direct models, which account for the micromodel geometry and underlying flow and transport physics, needed up to several days on supercomputers to resolve the more complex problems.
Book Synopsis 31. Forum Bauinformatik by : Sternal, Maximilian
Download or read book 31. Forum Bauinformatik written by Sternal, Maximilian and published by Universitätsverlag der TU Berlin. This book was released on 2019-09-17 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Das Forum Bauinformatik steht unter dem Motto „von jungen Forschenden für junge Forschende“. Es bietet jungen Wissenschaftlerinnen und Wissenschaftlern sowie interessierten Studierenden die Möglichkeit, ihre Forschungsarbeiten zu präsentieren, Problemstellungen fachspezifisch zu diskutieren und sich ganz allgemein über den neusten Stand der Forschung zu informieren. Zudem ergibt sich dadurch eine ausgezeichnete Gelegenheit, in die wissenschaftliche Gemeinschaft im Bereich der Bauinformatik einzusteigen und Kontakte zu anderen Forschenden zu knüpfen. According to the motto “from young researchers for young researchers” the Forum Bauinformatik offers researchers as well as interested undergraduates the opportunity to present their research work, to discuss discipline-specific problems and to catch up to the current state in research. Furthermore, it gives an excellent chance to get in touch with the scientific community in the field of Computing in Civil Engineering and socialize with other researchers
Book Synopsis Pore Scale Simulation of Transport in Porous Media by :
Download or read book Pore Scale Simulation of Transport in Porous Media written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: When performing solute transport in porous media one often observes an asymmetric break-through curve with a very slow decline of the concentration. This phenomenon even appears with non-sorbing solutes and is known as tailing. There are several hypotheses to explain this phenomenon. The modelling is often done using the mobile-immobile model (MIM), which assumes that parts of the solvent are not moving along with the general flow. The solutes can move into these stagnant zones by diffusion which leads to the observed tailing. In this thesis it is checked whether tailing can indeed be explained by stagnant zones, which may result e.g. from dead-end pores or pores perpendicular to the direction of the flow. A program to simulate transport in porous media was developed and verified using several test-problems. An example calculation with a randomly generated porous medium was performed. The resulting break-through curves showed significant tailing.
Book Synopsis Direct Pore-level Modeling of Fluid Flow in Porous Media by : Saeed Ovaysi
Download or read book Direct Pore-level Modeling of Fluid Flow in Porous Media written by Saeed Ovaysi and published by . This book was released on 2010 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: A three-dimensional fully parallel particle-based model for direct pore-level simulation of incompressible viscous fluid flow in disordered porous media is presented. The model is capable of simulating flow in porous media, taking directly as input three-dimensional high-resolution microtomography images of naturally-occurring or man-made porous systems. These images provide the most faithful representations of the pore space in the porous medium. In this method, the entire medium, i.e., solid and fluid, is discretized using particles. The model is based on the Moving Particle Semi-implicit (MPS) technique and modified to improve its stability. The model handles highly irregular fluid-solid boundaries effectively, accounts for viscous pressure drop in addition to gravity forces, conserves mass, and can automatically detect any false connectivities with fluid particles in the neighboring pores and throats. The model also includes a sophisticated algorithm to automatically split and merge fluid particles to maintain hydraulic connectivity of extremely narrow conduits. Finally, it uses novel methods to handle particle inconsistencies and open boundaries. To handle the computational load, a fully parallel version of the model is presented that runs on distributed memory computer clusters and exhibits excellent scalability. The accuracy and reliability of the model in predicting the true flow in porous systems was validated rigorously against analytical, numerical, and experimental data available in the literature. The validated model was then used to simulate flow in naturally-occurring sandstones to compute their absolute permeabilities and their variations with sample size and flow direction. The model was extended to handle the pore-level transport of solutes in random porous media. Two different sandstones possessing different topologies were used to investigate pre-asymptotic and asymptotic longitudinal dispersion coefficients, the impact of pore-scale topologies on the transient behavior of convective-diffusive solute transport at the pore-level, and the impact of inertial forces on dispersion coefficients at very high Peclet numbers. The asymptotic dispersion coefficients were then successfully compared against the experimental data available in the literature for a wide range of Peclet number. Furthermore, a solute adsorption module was developed and integrated with the model allowing us to study the adsorptive-diffusive-convective solute transport in a rough-walled single fracture. These studies provide new insights into the pore-scale behavior of fluid flow and solute transport in random porous media. The model serves as a reliable platform for studies of different pore-level phenomena that can improve our understanding of the pore-level physics of flow and transport.
Book Synopsis Recent Advances in Problems of Flow and Transport in Porous Media by : J.M. Crolet
Download or read book Recent Advances in Problems of Flow and Transport in Porous Media written by J.M. Crolet and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Porous media, and especially phenomena of transport in such materials, are an impor1ant field of interest for geologists, hydrogeologists, researchers in soil and fluid mechanics, petroleum and chemical engineers, physicists and scientists in many other disciplines. The development of better numerical simulation techniques in combination with the enormous expansion of computer tools, have enabled numerical simulation of transport phenomena (mass of phases and components, energy etc. ) in porous domains of interest. Before any practical application of the results of such simulations can be used, it is essential that the simulation models have been proven to be valid. In order to establish the greatest possible coherence between the models and the physical reality, frequent interaction between numericians, mathematicians and the previously quoted researchers, is necessary. Once this coherence is established, the numerical simulations could be used to predict various phenomena such as water management, propagation of pollutants etc. These simulations could be, in many cases, the only financially acceptable tool to carry out an investigation. Current studies within various fields of applications include not only physical comprehension aspects of flow and energy or solute transport in saturated or unsaturated media but also numerical aspects in deriving strong complex equations. Among the various fields of applications generally two types of problems can be observed. Those associated with the pollution of the environment and those linked to water management. The former are essentially a problem in industrialized countries, the latter are a major source of concern in North-Africa.
Book Synopsis Elucidating Microbial Processes in Soils and Sediments: Microscale Measurements and Modeling, 2nd Edition by : Philippe C. Baveye
Download or read book Elucidating Microbial Processes in Soils and Sediments: Microscale Measurements and Modeling, 2nd Edition written by Philippe C. Baveye and published by Frontiers Media SA. This book was released on 2020-03-27 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: Half a century ago, soil ...
Book Synopsis Computational Methods for Flow and Transport in Porous Media by : J.M. Crolet
Download or read book Computational Methods for Flow and Transport in Porous Media written by J.M. Crolet and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first Symposium on Recent Advances in Problems of Flow and Transport in Porous Media was held in Marrakech in June '96 and has provided a focus for the utilization of computer methods for solving the many complex problems encountered in the field of solute transport in porous media. This symposium has been successful in bringing together scientists, physicists, hydrogeologists, researchers in soil and fluid mechanics and engineers involved in this multidisciplinary subject. It is clear that the utilization of computer-based models in this domain is still rapidly expanding and that new and novel solutions are being developed. The contributed papers which form this book reflect the recent advances, in particular with respect to new methods, inverse problems, reactive transport, unsaturated media and upscaling. These have been subdivided into the following sections: I. Numerical methods II. Mass transport and heat transfer III. Comparison with experimentation and simulation of real cases This book contains reviewed articles of the top presentations held during the International Symposium on Computer Methods in Porous Media Engineering which took place in Giens (France) in October 1998. All of the presentations and the optimism shown during the meeting provided further evidence that computer modeling is making remarkable progress and is indeed becoming an essential toolkit in the field of porous media and solute transport. I believe that the content of this book provides evidence of this and furthermore gives a comprehensive review of the theoretical developments and applications.
Book Synopsis Dynamic Pore Network Modeling of Two-phase Flow and Solute Transport in Disordered Porous Media and Rough-walled Fractures by : Yanbin Gong
Download or read book Dynamic Pore Network Modeling of Two-phase Flow and Solute Transport in Disordered Porous Media and Rough-walled Fractures written by Yanbin Gong and published by . This book was released on 2021 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reliable, physics-based predictions of two-phase flow and solute transport properties (e.g., relative permeability and dispersion coefficient) of porous media and fractures are crucial for reducing the uncertainty in performance predictions of many subsurface applications such as carbon dioxide (CO2) sequestration, enhanced oil recovery, and remediation of contaminated groundwater. However, problems of multi-phase flow in disordered porous media are exceedingly difficult due to, for instance, complicated pore space geometries and topologies, wettability conditions, and fluid–fluid displacements. Furthermore, even though the majority of subsurface reservoirs have natural or induced fractures, there is still no consensus regarding two-phase fluid flow behaviors in rough-walled fractures because of the intricate aperture-field geometries and their impacts on fluid–fluid interactions. Therefore, the development of physics-based models that can accurately predict flow and transport properties of disordered porous media and rough-walled fractures is warranted. In this study, we developed two new heavily-parallelized, dynamic pore-scale modeling platforms that can better account for the underlying displacement and transport physics and thereby predict the corresponding macroscopic properties. Both modeling frameworks incorporate many advanced features that have not been collectively used in previous dynamic models. For instance, they rigorously solve for the capillary, viscous, and buoyancy forces, integrate detailed descriptions of pore-scale fluid displacement dynamics, and explicitly account for flow through wetting layers forming in corners and rough surfaces of pore spaces. These modeling platforms further benefit from heavy parallelization and advanced domain decomposition techniques to achieve computational efficiency. We utilize the dynamic models to carry out various two-phase displacement simulations in core-sized pore networks constructed from high-resolution x-ray images of sandstone rock samples and a Berea sandstone fracture. Measured two-phase relative permeability data and fluid occupancy maps for both primary drainage and imbibition displacements are employed to validate our network models and probe their predictive capabilities. Afterward, the validated models are utilized to investigate a series of critical two-phase flow and solute transport properties including fluid trapping behaviors in porous media and rough-walled fractures under a broad range of fluid properties and flow conditions, relative permeability curves of single fractures with different geometric features, and dispersive solute transport behaviors in a sandstone rock sample under both single- and two-phase fluid configurations. These findings are of fundamental importance to understanding the physics governing fluid flow and solute transport in subsurface systems as well as field-scale predictions of two-phase flow in porous media and fractures.
Book Synopsis Recent Advancements in X-Ray and Neutron Imaging of Dynamic Processes in Earth Sciences by : Lucia Mancini
Download or read book Recent Advancements in X-Ray and Neutron Imaging of Dynamic Processes in Earth Sciences written by Lucia Mancini and published by Frontiers Media SA. This book was released on 2020-12-01 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.
Book Synopsis 3D Coupled Pore-network Modelling of Flow and Solute Transport Through Porous Media, from Laminar to Turbulent Flow by : A. A. El-Zehairy
Download or read book 3D Coupled Pore-network Modelling of Flow and Solute Transport Through Porous Media, from Laminar to Turbulent Flow written by A. A. El-Zehairy and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis 3D Coupled Pore-network Modelling of Flow and Solute Transport Through Porous Media, from Laminar to Turbulent Flow by : Amr A. El-Zehairy
Download or read book 3D Coupled Pore-network Modelling of Flow and Solute Transport Through Porous Media, from Laminar to Turbulent Flow written by Amr A. El-Zehairy and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Simulation of Flow and Transport at the Micro (Pore) Scale by :
Download or read book Simulation of Flow and Transport at the Micro (Pore) Scale written by and published by . This book was released on 2007 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important problem in porous media involves the ability of micron and submicron-sized biological particles such as viruses or bacteria to move in groundwater systems through geologic media characterized by rock or mixed gravel, clay and sand materials. Current simulation capabilities require properly upscaled (continuum) models of colloidal filtration and adsorption to augment existing theories of fluid flow and chemical transport. Practical models typically address flow and transport behavior in aquifers over distances of 1 to 10 km where, for example, fluid momentum balance is governed by the simple Darcy's Law as a function of a pressure gradient, elevation gradient and a medium-dependent permeability parameter. In addition to fluid advection, there are multiple transport processes occurring in these systems including diffusion, dispersion and chemical interactions with solids or other aqueous chemical species. Particle transport is typically modeled in the same way as dissolved species, except that additional loss terms are incorporated to model particle filtration (physical interception), adsorption (chemical interception) and inactivation. Proper resolution of these processes at the porous medium continuum scale constitutes an important closure problem in subsurface science. We present a new simulation capability based on enabling technologies developed for microfluidics applications to model transport of colloidal-sized particles at the microscale, with relevance to the pore scale in geophysical subsurface systems. Particulate is represented by a bead-rod polymer model and is fully-coupled to a Newtonian solvent described by Navier-Stokes. Finite differences are used to discretize the interior of the domain; a Cartesian grid embedded boundary/volume-of-fluid method is used near boundaries and interfaces. This approach to complex geometry is amenable to direct simulation on grids obtained from surface extractions of tomographic image data. Short-range interactions are included in the particle model. This capability has been previously demonstrated on polymer flow in spatially-resolved packed bed (3D) and post array (2D) systems. We also discuss the advantages of this approach for the development of high-resolution adaptive algorithms for multiscale continuum-particle and mesoscale coarse-grained molecular dynamics models.
Book Synopsis Simulation of Fluid Flow and Solute Transport in Fractured Media Using Boundary Integral Element Methods by : James Homer Ferguson
Download or read book Simulation of Fluid Flow and Solute Transport in Fractured Media Using Boundary Integral Element Methods written by James Homer Ferguson and published by . This book was released on 1989 with total page 878 pages. Available in PDF, EPUB and Kindle. Book excerpt:
