On the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlation
Autor(a) principal: | |
---|---|
Data de Publicação: | 2023 |
Tipo de documento: | Tese |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFSCAR |
Texto Completo: | https://repositorio.ufscar.br/handle/ufscar/18583 |
Resumo: | In particle-laden flows, it is essential to model the fluid-particle interaction. However, depending on effects such as friction and attraction, surface properties, and collisions, particles can agglomerate, generating new irregularly-shaped particles. Such phenomenon is relevant since the geometry directly interferes with the flow dynamics. One way to evaluate how the particle will interfere is through the drag force. In the theoretical development of equipment, this force is taken into account and represented by the drag coefficient and is highly dependent on two variables: particle geometry and flow velocity. In the literature, several correlations are observed, obtained both in the experimental field or numerical field, using computational fluid dynamics (CFD). The advantage of using CFD lies in the ease of varying the flow velocity and in obtaining the drag coefficient from the pressure and velocity fields. However, most of these methods employ transient formulations, resulting in highly detailed but computationally expensive outcomes. This cost increases exponentially as the Reynolds number of the flow increases, making the study of turbulent flows infeasible. Consequently, these models are generally obtained for Reynolds numbers below 300 and then extrapolated to higher values when implemented in CFD codes. Thus, this study proposes an alternative approach to the problem by using steady formulation simulations, aiming to reduce computational costs and proposing a new, simple, and unified correlation for the drag coefficient capable of encompassing a wide range of flows, from laminar to turbulent, applicable to irregularly shaped particles and easily implementable in CFD codes. Using CFD simulations with experimental validation, it was possible to obtain the characteristic drag coefficient curve over a wide range of Reynolds numbers (0.1 ≤ Re ≤ 3500) for agglomerates of spheres representing irregularly-shaped particles. By individually simulating the flow around these agglomerates while varying the geometries and flow velocities, a new correlation for calculating the drag coefficient was proposed, capable of fitting the obtained characteristic curves. In general, the results showed that the use of a steady formulation can yield good results provided that the mesh is properly refined and the turbulence model accurately represents the flow. The new correlation, combined with the use of flatness as a geometric characterization parameter, proved effective in representing the drag curve, with maximum, minimum, and average deviations of 10.78%, -7.62%, and 3.79%, respectively, compared to simulated results, and 14.36%, -12.36%, and 9.6% compared to experimental results. |
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Oliveira, Ricardo Arbach Fernandes deLopes, Gabriela Cantarellihttp://lattes.cnpq.br/5680967191791061http://lattes.cnpq.br/7351904823405755https://orcid.org/0000-0002-4337-9351https://orcid.org/0000-0002-4475-60754faf8c2f-3126-4246-8961-23ae4d8919262023-09-21T14:30:54Z2023-09-21T14:30:54Z2023-07-31OLIVEIRA, Ricardo Arbach Fernandes de. On the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlation. 2023. Tese (Doutorado em Engenharia Química) – Universidade Federal de São Carlos, São Carlos, 2023. Disponível em: https://repositorio.ufscar.br/handle/ufscar/18583.https://repositorio.ufscar.br/handle/ufscar/18583In particle-laden flows, it is essential to model the fluid-particle interaction. However, depending on effects such as friction and attraction, surface properties, and collisions, particles can agglomerate, generating new irregularly-shaped particles. Such phenomenon is relevant since the geometry directly interferes with the flow dynamics. One way to evaluate how the particle will interfere is through the drag force. In the theoretical development of equipment, this force is taken into account and represented by the drag coefficient and is highly dependent on two variables: particle geometry and flow velocity. In the literature, several correlations are observed, obtained both in the experimental field or numerical field, using computational fluid dynamics (CFD). The advantage of using CFD lies in the ease of varying the flow velocity and in obtaining the drag coefficient from the pressure and velocity fields. However, most of these methods employ transient formulations, resulting in highly detailed but computationally expensive outcomes. This cost increases exponentially as the Reynolds number of the flow increases, making the study of turbulent flows infeasible. Consequently, these models are generally obtained for Reynolds numbers below 300 and then extrapolated to higher values when implemented in CFD codes. Thus, this study proposes an alternative approach to the problem by using steady formulation simulations, aiming to reduce computational costs and proposing a new, simple, and unified correlation for the drag coefficient capable of encompassing a wide range of flows, from laminar to turbulent, applicable to irregularly shaped particles and easily implementable in CFD codes. Using CFD simulations with experimental validation, it was possible to obtain the characteristic drag coefficient curve over a wide range of Reynolds numbers (0.1 ≤ Re ≤ 3500) for agglomerates of spheres representing irregularly-shaped particles. By individually simulating the flow around these agglomerates while varying the geometries and flow velocities, a new correlation for calculating the drag coefficient was proposed, capable of fitting the obtained characteristic curves. In general, the results showed that the use of a steady formulation can yield good results provided that the mesh is properly refined and the turbulence model accurately represents the flow. The new correlation, combined with the use of flatness as a geometric characterization parameter, proved effective in representing the drag curve, with maximum, minimum, and average deviations of 10.78%, -7.62%, and 3.79%, respectively, compared to simulated results, and 14.36%, -12.36%, and 9.6% compared to experimental results.Em escoamentos carregados de partículas, é essencial modelar a interação fluido-partícula. Porém, a depender de efeitos como atração e atrito entre partículas, propriedades superficiais e colisões, as partículas podem se aglomerar, formando novas partículas de formatos irregulares. Tal fenômeno tem sua importância, visto que sua geometria altera diretamente a dinâmica do escoamento. Uma maneira de avaliar a forma como a partícula interfere no escoamento é utilizando a força de arraste. No desenvolvimento teórico de equipamentos, tal força é levada em consideração, sendo representada pelo coeficiente de arraste e é altamente dependente de duas variáveis: geometria da partícula e velocidade do escoamento. Na literatura, são observadas diversas correlações, obtidas tanto experimentalmente quanto numericamente, utilizando técnicas de fluidodinâmica computacional (CFD). A vantagem do uso de métodos numéricos se dá na facilidade de se variar a velocidade do escoamento, bem como no cálculo do coeficiente de arraste a partir dos campos de pressão. Porém, a maioria destes utilizam métodos de formulação transiente, obtendo resultados com elevados níveis de detalhamento, mas de alto custo computacional, que aumenta exponencialmente quanto maior o número de Reynolds. Deste modo, tais modelos são obtidos, em geral, para valores de Reynolds inferiores a 300 e extrapolados para valores elevados ao serem implementados em códigos de CFD. Assim, neste estudo foram propostas tanto uma maneira alternativa de abordar o problema, utilizando simulações de formulação estacionária, reduzindo o custo computacional, quanto uma nova correlação de coeficiente de arraste simples e unificada, capaz de abranger amplas faixas de escoamento, do laminar ao turbulento, aplicável a partículas irregulares, e de fácil implementação em códigos de CFD. Utilizando-se de CFD com validação experimental, foi possível obter a curva característica de coeficiente de arraste ao longo de uma ampla faixa de números de Reynolds (0,1 ≤ Re ≤ 3500) para aglomerados de esferas, que representavam partículas de formatos irregulares. Ao simular individualmente o escoamento de um fluido ao redor de tais aglomerados, variando as geometrias e velocidade do escoamento, foi possível propor a nova correlação de cálculo de coeficiente de arraste capaz de se ajustar às curvas características obtidas. Em linhas gerais, os resultados obtidos mostraram que o uso de uma formulação estacionário é capaz de obter bons resultados, desde que a malha seja corretamente refinada e o modelo de turbulência seja capaz de representar corretamente o escoamento. A nova correlação, aliada ao uso do achatamento como parâmetro de caracterização geométrica, mostrou-se eficaz em representar a curva de arraste, apresentando desvios máximo, mínimo e médio de 10,78%, -7,62% e 3,79%, respectivamente, em relação aos resultados simulados, e 14,36%, -12,36% e 9,6% em relação aos resultados experimentais.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)140412/2020-4engUniversidade Federal de São CarlosCâmpus São CarlosPrograma de Pós-Graduação em Engenharia Química - PPGEQUFSCarAttribution-NonCommercial-NoDerivs 3.0 Brazilhttp://creativecommons.org/licenses/by-nc-nd/3.0/br/info:eu-repo/semantics/openAccessMaterial particuladoAglomerados de partículasPartículas de formatos irregularesCoeficiente de arrasteFluidodinâmica computacionalParticulate matterParticle agglomeratesIrregularly-shaped particlesDrag coefficientComputational fluid dynamicsENGENHARIAS::ENGENHARIA QUIMICA::PROCESSOS INDUSTRIAIS DE ENGENHARIA QUIMICAOn the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlationEstudo do coeficiente de arraste em aglomerados de partículas: uma nova correlação de coeficiente de arraste utilizando CFDinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesis600600ad966bd7-9d47-4f1b-9732-0ad2f0578e62reponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINALThesis_Oliveira_RAF.pdfThesis_Oliveira_RAF.pdfapplication/pdf3997685https://repositorio.ufscar.br/bitstream/ufscar/18583/3/Thesis_Oliveira_RAF.pdf96aeedcd46c7f183eef1c9d440fa5883MD53CC-LICENSElicense_rdflicense_rdfapplication/rdf+xml; charset=utf-8810https://repositorio.ufscar.br/bitstream/ufscar/18583/4/license_rdff337d95da1fce0a22c77480e5e9a7aecMD54TEXTThesis_Oliveira_RAF.pdf.txtThesis_Oliveira_RAF.pdf.txtExtracted texttext/plain204338https://repositorio.ufscar.br/bitstream/ufscar/18583/5/Thesis_Oliveira_RAF.pdf.txt35e1598d9a9a494baba60a46948ea69dMD55ufscar/185832024-05-14 17:43:59.791oai:repositorio.ufscar.br:ufscar/18583Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222024-05-14T17:43:59Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.eng.fl_str_mv |
On the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlation |
dc.title.alternative.por.fl_str_mv |
Estudo do coeficiente de arraste em aglomerados de partículas: uma nova correlação de coeficiente de arraste utilizando CFD |
title |
On the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlation |
spellingShingle |
On the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlation Oliveira, Ricardo Arbach Fernandes de Material particulado Aglomerados de partículas Partículas de formatos irregulares Coeficiente de arraste Fluidodinâmica computacional Particulate matter Particle agglomerates Irregularly-shaped particles Drag coefficient Computational fluid dynamics ENGENHARIAS::ENGENHARIA QUIMICA::PROCESSOS INDUSTRIAIS DE ENGENHARIA QUIMICA |
title_short |
On the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlation |
title_full |
On the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlation |
title_fullStr |
On the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlation |
title_full_unstemmed |
On the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlation |
title_sort |
On the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlation |
author |
Oliveira, Ricardo Arbach Fernandes de |
author_facet |
Oliveira, Ricardo Arbach Fernandes de |
author_role |
author |
dc.contributor.authorlattes.por.fl_str_mv |
http://lattes.cnpq.br/7351904823405755 |
dc.contributor.authororcid.por.fl_str_mv |
https://orcid.org/0000-0002-4337-9351 |
dc.contributor.advisor1orcid.por.fl_str_mv |
https://orcid.org/0000-0002-4475-6075 |
dc.contributor.author.fl_str_mv |
Oliveira, Ricardo Arbach Fernandes de |
dc.contributor.advisor1.fl_str_mv |
Lopes, Gabriela Cantarelli |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/5680967191791061 |
dc.contributor.authorID.fl_str_mv |
4faf8c2f-3126-4246-8961-23ae4d891926 |
contributor_str_mv |
Lopes, Gabriela Cantarelli |
dc.subject.por.fl_str_mv |
Material particulado Aglomerados de partículas Partículas de formatos irregulares Coeficiente de arraste Fluidodinâmica computacional |
topic |
Material particulado Aglomerados de partículas Partículas de formatos irregulares Coeficiente de arraste Fluidodinâmica computacional Particulate matter Particle agglomerates Irregularly-shaped particles Drag coefficient Computational fluid dynamics ENGENHARIAS::ENGENHARIA QUIMICA::PROCESSOS INDUSTRIAIS DE ENGENHARIA QUIMICA |
dc.subject.eng.fl_str_mv |
Particulate matter Particle agglomerates Irregularly-shaped particles Drag coefficient Computational fluid dynamics |
dc.subject.cnpq.fl_str_mv |
ENGENHARIAS::ENGENHARIA QUIMICA::PROCESSOS INDUSTRIAIS DE ENGENHARIA QUIMICA |
description |
In particle-laden flows, it is essential to model the fluid-particle interaction. However, depending on effects such as friction and attraction, surface properties, and collisions, particles can agglomerate, generating new irregularly-shaped particles. Such phenomenon is relevant since the geometry directly interferes with the flow dynamics. One way to evaluate how the particle will interfere is through the drag force. In the theoretical development of equipment, this force is taken into account and represented by the drag coefficient and is highly dependent on two variables: particle geometry and flow velocity. In the literature, several correlations are observed, obtained both in the experimental field or numerical field, using computational fluid dynamics (CFD). The advantage of using CFD lies in the ease of varying the flow velocity and in obtaining the drag coefficient from the pressure and velocity fields. However, most of these methods employ transient formulations, resulting in highly detailed but computationally expensive outcomes. This cost increases exponentially as the Reynolds number of the flow increases, making the study of turbulent flows infeasible. Consequently, these models are generally obtained for Reynolds numbers below 300 and then extrapolated to higher values when implemented in CFD codes. Thus, this study proposes an alternative approach to the problem by using steady formulation simulations, aiming to reduce computational costs and proposing a new, simple, and unified correlation for the drag coefficient capable of encompassing a wide range of flows, from laminar to turbulent, applicable to irregularly shaped particles and easily implementable in CFD codes. Using CFD simulations with experimental validation, it was possible to obtain the characteristic drag coefficient curve over a wide range of Reynolds numbers (0.1 ≤ Re ≤ 3500) for agglomerates of spheres representing irregularly-shaped particles. By individually simulating the flow around these agglomerates while varying the geometries and flow velocities, a new correlation for calculating the drag coefficient was proposed, capable of fitting the obtained characteristic curves. In general, the results showed that the use of a steady formulation can yield good results provided that the mesh is properly refined and the turbulence model accurately represents the flow. The new correlation, combined with the use of flatness as a geometric characterization parameter, proved effective in representing the drag curve, with maximum, minimum, and average deviations of 10.78%, -7.62%, and 3.79%, respectively, compared to simulated results, and 14.36%, -12.36%, and 9.6% compared to experimental results. |
publishDate |
2023 |
dc.date.accessioned.fl_str_mv |
2023-09-21T14:30:54Z |
dc.date.available.fl_str_mv |
2023-09-21T14:30:54Z |
dc.date.issued.fl_str_mv |
2023-07-31 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
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doctoralThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
OLIVEIRA, Ricardo Arbach Fernandes de. On the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlation. 2023. Tese (Doutorado em Engenharia Química) – Universidade Federal de São Carlos, São Carlos, 2023. Disponível em: https://repositorio.ufscar.br/handle/ufscar/18583. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufscar.br/handle/ufscar/18583 |
identifier_str_mv |
OLIVEIRA, Ricardo Arbach Fernandes de. On the drag coefficient in particle agglomerates: a CFD approach to propose a new drag correlation. 2023. Tese (Doutorado em Engenharia Química) – Universidade Federal de São Carlos, São Carlos, 2023. Disponível em: https://repositorio.ufscar.br/handle/ufscar/18583. |
url |
https://repositorio.ufscar.br/handle/ufscar/18583 |
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eng |
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eng |
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600 600 |
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Attribution-NonCommercial-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nc-nd/3.0/br/ info:eu-repo/semantics/openAccess |
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Attribution-NonCommercial-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nc-nd/3.0/br/ |
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openAccess |
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Universidade Federal de São Carlos Câmpus São Carlos |
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Programa de Pós-Graduação em Engenharia Química - PPGEQ |
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UFSCar |
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Universidade Federal de São Carlos Câmpus São Carlos |
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