Convective mixing in heterogeneous porous media

This thesis seeks to advance the understanding of convective mixing in heterogeneous porous media, a topic that remains comparatively underexplored compared to its homogeneous counterpart. Through the combination of high-resolution numerical simulations and laboratory experiments, we explore how spa...

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Autor: Benhammadi, Rima
Tipo de recurso: otro
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/413084
Acceso en línea:http://hdl.handle.net/10261/413084
Access Level:acceso abierto
Palabra clave:Convective mixing
Heterogeneous porous media
http://metadata.un.org/sdg/7
http://metadata.un.org/sdg/11
http://metadata.un.org/sdg/9
Ensure access to affordable, reliable, sustainable and modern energy for all
Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation
Make cities and human settlements inclusive, safe, resilient and sustainable
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oai_identifier_str oai:digital.csic.es:10261/413084
network_acronym_str ES
network_name_str España
repository_id_str
dc.title.none.fl_str_mv Convective mixing in heterogeneous porous media
title Convective mixing in heterogeneous porous media
spellingShingle Convective mixing in heterogeneous porous media
Benhammadi, Rima
Convective mixing
Heterogeneous porous media
http://metadata.un.org/sdg/7
http://metadata.un.org/sdg/11
http://metadata.un.org/sdg/9
Ensure access to affordable, reliable, sustainable and modern energy for all
Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation
Make cities and human settlements inclusive, safe, resilient and sustainable
title_short Convective mixing in heterogeneous porous media
title_full Convective mixing in heterogeneous porous media
title_fullStr Convective mixing in heterogeneous porous media
title_full_unstemmed Convective mixing in heterogeneous porous media
title_sort Convective mixing in heterogeneous porous media
dc.creator.none.fl_str_mv Benhammadi, Rima
author Benhammadi, Rima
author_facet Benhammadi, Rima
author_role author
dc.contributor.none.fl_str_mv Dentz, Hidalgo, Juan J. Marco
Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
dc.subject.none.fl_str_mv Convective mixing
Heterogeneous porous media
http://metadata.un.org/sdg/7
http://metadata.un.org/sdg/11
http://metadata.un.org/sdg/9
Ensure access to affordable, reliable, sustainable and modern energy for all
Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation
Make cities and human settlements inclusive, safe, resilient and sustainable
topic Convective mixing
Heterogeneous porous media
http://metadata.un.org/sdg/7
http://metadata.un.org/sdg/11
http://metadata.un.org/sdg/9
Ensure access to affordable, reliable, sustainable and modern energy for all
Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation
Make cities and human settlements inclusive, safe, resilient and sustainable
description This thesis seeks to advance the understanding of convective mixing in heterogeneous porous media, a topic that remains comparatively underexplored compared to its homogeneous counterpart. Through the combination of high-resolution numerical simulations and laboratory experiments, we explore how spatial variability in permeability influences the onset, development, and efficiency of convective mixing processes, with applications to thermal convection, CO dissolution and reactive transport. First, we begin by investigating thermal convection in the classic Horton-Rogers-Lapwood (HRL) configuration, where permeability fields are modeled as two-dimensional, log-normally distributed random fields with varying variance and correlation lengths. These serve as quantitative measures of the underlying heterogeneity. Our conducted parametric study shows that increasing the variance and/or the correlation length of the log-permeability field enhances segregation, sharpens thermal interfaces, and leads to more irregular flow structures. While the dissolution flux decreases with Rayleigh number in both homogeneous and heterogeneous systems, its sensitivity to permeability variance becomes more pronounced at longer correlation lengths. In highly heterogeneous cases, high-permeability zones near boundaries coincide with stagnation points that influence the formation of temperature plumes and localised strain rates, while the interface width decreases, indicating enhanced stretching and deformation due to the underlying structure. Next, we study CO convective dissolution in heterogeneous Hele-Shaw cells, via a combined experimental-numerical approach. Heterogeneity is introduced through variations in the cell gap width, corresponding to a log-normal distribution of permeability with fixed variance and correlation lengths. Results show that heterogeneity advances the onset of instability, increases the amplitude and growth rate of convective fingers, and causes more distorted and dispersive flow patterns. However, the dimensionless wavenumber of the instability remains similar to that in homogeneous cells. A comparison of the autocorrelation functions of the fingering patterns and the permeability field shows that heterogeneity increases the dimensionless correlation length of the fingering pattern, which in turn slows down its growth once the finger size becomes comparable to the heterogeneity scale. Finally, we investigate reactive convective dissolution involving the bimolecular chemical reaction , across four permeability configurations: homogeneous, horizontally layered, vertically layered, and multi-Gaussian log-normally distributed fields. Key metrics such as product mass, reaction rate, front position and width and mixing length are all substantially affected by the structure of the permeability field. Vertically layered and log-normal configurations promote more efficient mixing and faster front progression. Overall, when horizontal correlation length is small relative to the vertical, convective transport and mixing efficiency are maximised. Collectively, these findings demonstrate that it is not simply the presence of heterogeneity, but the specific structure of the permeability, particularly its variance and spatial correlation, that fundamentally governs convective behaviour. The insights gained show the necessity of incorporating geologically realistic heterogeneity into the predictive models.
publishDate 2025
dc.date.none.fl_str_mv 2025
2026
2026
dc.type.none.fl_str_mv info:eu-repo/semantics/other
http://purl.org/coar/resource_type/c_46ec
Publisher's version
info:eu-repo/semantics/publishedVersion
dc.type.openaire.fl_str_mv info:eu-repo/semantics/doctoralThesis
format other
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/413084
url http://hdl.handle.net/10261/413084
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv 10.5821/dissertation-2117-450029

dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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spelling Convective mixing in heterogeneous porous mediaBenhammadi, RimaConvective mixingHeterogeneous porous mediahttp://metadata.un.org/sdg/7http://metadata.un.org/sdg/11http://metadata.un.org/sdg/9Ensure access to affordable, reliable, sustainable and modern energy for allBuild resilient infrastructure, promote inclusive and sustainable industrialization and foster innovationMake cities and human settlements inclusive, safe, resilient and sustainableThis thesis seeks to advance the understanding of convective mixing in heterogeneous porous media, a topic that remains comparatively underexplored compared to its homogeneous counterpart. Through the combination of high-resolution numerical simulations and laboratory experiments, we explore how spatial variability in permeability influences the onset, development, and efficiency of convective mixing processes, with applications to thermal convection, CO dissolution and reactive transport. First, we begin by investigating thermal convection in the classic Horton-Rogers-Lapwood (HRL) configuration, where permeability fields are modeled as two-dimensional, log-normally distributed random fields with varying variance and correlation lengths. These serve as quantitative measures of the underlying heterogeneity. Our conducted parametric study shows that increasing the variance and/or the correlation length of the log-permeability field enhances segregation, sharpens thermal interfaces, and leads to more irregular flow structures. While the dissolution flux decreases with Rayleigh number in both homogeneous and heterogeneous systems, its sensitivity to permeability variance becomes more pronounced at longer correlation lengths. In highly heterogeneous cases, high-permeability zones near boundaries coincide with stagnation points that influence the formation of temperature plumes and localised strain rates, while the interface width decreases, indicating enhanced stretching and deformation due to the underlying structure. Next, we study CO convective dissolution in heterogeneous Hele-Shaw cells, via a combined experimental-numerical approach. Heterogeneity is introduced through variations in the cell gap width, corresponding to a log-normal distribution of permeability with fixed variance and correlation lengths. Results show that heterogeneity advances the onset of instability, increases the amplitude and growth rate of convective fingers, and causes more distorted and dispersive flow patterns. However, the dimensionless wavenumber of the instability remains similar to that in homogeneous cells. A comparison of the autocorrelation functions of the fingering patterns and the permeability field shows that heterogeneity increases the dimensionless correlation length of the fingering pattern, which in turn slows down its growth once the finger size becomes comparable to the heterogeneity scale. Finally, we investigate reactive convective dissolution involving the bimolecular chemical reaction , across four permeability configurations: homogeneous, horizontally layered, vertically layered, and multi-Gaussian log-normally distributed fields. Key metrics such as product mass, reaction rate, front position and width and mixing length are all substantially affected by the structure of the permeability field. Vertically layered and log-normal configurations promote more efficient mixing and faster front progression. Overall, when horizontal correlation length is small relative to the vertical, convective transport and mixing efficiency are maximised. Collectively, these findings demonstrate that it is not simply the presence of heterogeneity, but the specific structure of the permeability, particularly its variance and spatial correlation, that fundamentally governs convective behaviour. The insights gained show the necessity of incorporating geologically realistic heterogeneity into the predictive models.Peer reviewedDentz, Hidalgo, Juan J. MarcoConsejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]202620262025info:eu-repo/semantics/otherhttp://purl.org/coar/resource_type/c_46ecPublisher's versioninfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesishttp://hdl.handle.net/10261/413084reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Inglés10.5821/dissertation-2117-450029Síinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/4130842026-05-22T06:33:51Z
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