A new subgrid characteristic length for turbulence simulations on anisotropic grids

Direct numerical simulations of the incompressible Navier-Stokes equations are not feasible yet for most practical turbulent flows. Therefore, dynamically less complex mathematical formulations are necessary for coarse-grained simulations. In this regard, eddy-viscosity models for Large-Eddy Simulat...

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Detalhes bibliográficos
Autores: Trias Miquel, Francesc Xavier|||0000-0002-5966-0703, Gorobets, Andrei, Silvis, Maurits, Verstappen, R.W.C.P., Oliva Llena, Asensio|||0000-0002-2805-4794
Formato: artículo
Fecha de publicación:2017
País:España
Recursos:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/114556
Acesso em linha:https://hdl.handle.net/2117/114556
https://dx.doi.org/10.1063/1.5012546
Access Level:acceso abierto
Palavra-chave:Fluid dynamics
Turbulence
Turbulence simulations
Turbulent flows
Viscosity
Navier Stokes equations
Vortex dynamics
Dinàmica de fluids
Turbulència
Àrees temàtiques de la UPC::Física::Física de fluids
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spelling A new subgrid characteristic length for turbulence simulations on anisotropic gridsTrias Miquel, Francesc Xavier|||0000-0002-5966-0703Gorobets, AndreiSilvis, MauritsVerstappen, R.W.C.P.Oliva Llena, Asensio|||0000-0002-2805-4794Fluid dynamicsTurbulenceTurbulence simulationsTurbulent flowsViscosityNavier Stokes equationsVortex dynamicsDinàmica de fluidsTurbulènciaÀrees temàtiques de la UPC::Física::Física de fluidsDirect numerical simulations of the incompressible Navier-Stokes equations are not feasible yet for most practical turbulent flows. Therefore, dynamically less complex mathematical formulations are necessary for coarse-grained simulations. In this regard, eddy-viscosity models for Large-Eddy Simulation (LES) are probably the most popular example thereof. This type of models requires the calculation of a subgrid characteristic length which is usually associated with the local grid size. For isotropic grids, this is equal to the mesh step. However, for anisotropic or unstructured grids, such as the pancake-like meshes that are often used to resolve near-wall turbulence or shear layers, a consensus on defining the subgrid characteristic length has not been reached yet despite the fact that it can strongly affect the performance of LES models. In this context, a new definition of the subgrid characteristic length is presented in this work. This flow-dependent length scale is based on the turbulent, or subgrid stress, tensor and its representations on different grids. The simplicity and mathematical properties suggest that it can be a robust definition that minimizes the effects of mesh anisotropies on simulation results. The performance of the proposed subgrid characteristic length is successfully tested for decaying isotropic turbulence and a turbulent channel flow using artificially refined grids. Finally, a simple extension of the method for unstructured meshes is proposed and tested for a turbulent flow around a square cylinder. Comparisons with existing subgrid characteristic length scales show that the proposed definition is much more robust with respect to mesh anisotropies and has a great potential to be used in complex geometries where highly skewed (unstructured) meshes are present.Peer Reviewed20172017-11-2920182018-02-27journal articlehttp://purl.org/coar/resource_type/c_6501AMhttp://purl.org/coar/version/c_ab4af688f83e57aainfo:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/2117/114556https://dx.doi.org/10.1063/1.5012546reponame:UPCommons. Portal del coneixement obert de la UPCinstname:Universitat Politècnica de Catalunya (UPC)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:upcommons.upc.edu:2117/1145562026-05-27T15:37:01Z
dc.title.none.fl_str_mv A new subgrid characteristic length for turbulence simulations on anisotropic grids
title A new subgrid characteristic length for turbulence simulations on anisotropic grids
spellingShingle A new subgrid characteristic length for turbulence simulations on anisotropic grids
Trias Miquel, Francesc Xavier|||0000-0002-5966-0703
Fluid dynamics
Turbulence
Turbulence simulations
Turbulent flows
Viscosity
Navier Stokes equations
Vortex dynamics
Dinàmica de fluids
Turbulència
Àrees temàtiques de la UPC::Física::Física de fluids
title_short A new subgrid characteristic length for turbulence simulations on anisotropic grids
title_full A new subgrid characteristic length for turbulence simulations on anisotropic grids
title_fullStr A new subgrid characteristic length for turbulence simulations on anisotropic grids
title_full_unstemmed A new subgrid characteristic length for turbulence simulations on anisotropic grids
title_sort A new subgrid characteristic length for turbulence simulations on anisotropic grids
dc.creator.none.fl_str_mv Trias Miquel, Francesc Xavier|||0000-0002-5966-0703
Gorobets, Andrei
Silvis, Maurits
Verstappen, R.W.C.P.
Oliva Llena, Asensio|||0000-0002-2805-4794
author Trias Miquel, Francesc Xavier|||0000-0002-5966-0703
author_facet Trias Miquel, Francesc Xavier|||0000-0002-5966-0703
Gorobets, Andrei
Silvis, Maurits
Verstappen, R.W.C.P.
Oliva Llena, Asensio|||0000-0002-2805-4794
author_role author
author2 Gorobets, Andrei
Silvis, Maurits
Verstappen, R.W.C.P.
Oliva Llena, Asensio|||0000-0002-2805-4794
author2_role author
author
author
author
dc.subject.none.fl_str_mv Fluid dynamics
Turbulence
Turbulence simulations
Turbulent flows
Viscosity
Navier Stokes equations
Vortex dynamics
Dinàmica de fluids
Turbulència
Àrees temàtiques de la UPC::Física::Física de fluids
topic Fluid dynamics
Turbulence
Turbulence simulations
Turbulent flows
Viscosity
Navier Stokes equations
Vortex dynamics
Dinàmica de fluids
Turbulència
Àrees temàtiques de la UPC::Física::Física de fluids
description Direct numerical simulations of the incompressible Navier-Stokes equations are not feasible yet for most practical turbulent flows. Therefore, dynamically less complex mathematical formulations are necessary for coarse-grained simulations. In this regard, eddy-viscosity models for Large-Eddy Simulation (LES) are probably the most popular example thereof. This type of models requires the calculation of a subgrid characteristic length which is usually associated with the local grid size. For isotropic grids, this is equal to the mesh step. However, for anisotropic or unstructured grids, such as the pancake-like meshes that are often used to resolve near-wall turbulence or shear layers, a consensus on defining the subgrid characteristic length has not been reached yet despite the fact that it can strongly affect the performance of LES models. In this context, a new definition of the subgrid characteristic length is presented in this work. This flow-dependent length scale is based on the turbulent, or subgrid stress, tensor and its representations on different grids. The simplicity and mathematical properties suggest that it can be a robust definition that minimizes the effects of mesh anisotropies on simulation results. The performance of the proposed subgrid characteristic length is successfully tested for decaying isotropic turbulence and a turbulent channel flow using artificially refined grids. Finally, a simple extension of the method for unstructured meshes is proposed and tested for a turbulent flow around a square cylinder. Comparisons with existing subgrid characteristic length scales show that the proposed definition is much more robust with respect to mesh anisotropies and has a great potential to be used in complex geometries where highly skewed (unstructured) meshes are present.
publishDate 2017
dc.date.none.fl_str_mv 2017
2017-11-29
2018
2018-02-27
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
AM
http://purl.org/coar/version/c_ab4af688f83e57aa
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/2117/114556
https://dx.doi.org/10.1063/1.5012546
url https://hdl.handle.net/2117/114556
https://dx.doi.org/10.1063/1.5012546
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv reponame:UPCommons. Portal del coneixement obert de la UPC
instname:Universitat Politècnica de Catalunya (UPC)
instname_str Universitat Politècnica de Catalunya (UPC)
reponame_str UPCommons. Portal del coneixement obert de la UPC
collection UPCommons. Portal del coneixement obert de la UPC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,301603

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