A time self-adaptive multilevel algorithm for large-eddy simulation
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| Title: | A time self-adaptive multilevel algorithm for large-eddy simulation |
|---|---|
| Authors: | Terracol, M.1 terracol@onera.fr, Sagaut, P.1, Basdevant, C.2 |
| Source: | Journal of Computational Physics. Jan2003, Vol. 184 Issue 2, p339. 27p. |
| Subjects: | Simulation methods & models, Multilevel models |
| Abstract: | An extension of the multilevel method applied to LES proposed in Terracol et al. [J. Comput. Phys. 167 (2001) 439] is introduced here to reduce the CPU times in unsteady simulation of turbulent flows. Flow variables are decomposed into several wavenumber bands, each band being associated to a computational grid in physical space. The general framework associated to such a decomposition is presented, and a new adapted closure is proposed for the subgrid terms which appear at each filtering level, while the closure at the finest level is performed with a classical LES model. CPU time saving is obtained by the use of V-cycles, as in the multigrid terminology. The main part of the simulation is thus performed on the coarse levels, while the smallest resolved scales are kept frozen (quasi-static approximation [Comput. Methods Appl. Mech. Engrg. 159 (1998) 123]). This allows to reduce significantly the CPU times in comparison with classical LES, while the accuracy of the simulation is preserved by the use of a fine discretization level. To ensure the validity of the quasi-static approximation, a dynamic evaluation of the time during which it remains valid is performed at each level through an a priori error estimation of the small-scales time variation. This leads to a totally self-adaptive method in which both the number of levels and the integration times on each grid level are evaluated dynamically. The method is assessed on a fully unsteady time-developing compressible mixing layer at a low-Reynolds number for which a DNS has also been performed, and in the inviscid case. Finally, a plane channel flow configuration has been considered. In all cases, the results obtained are in good agreement with classical LES performed on a fine grid, with CPU time reduction factors of up to five. [Copyright &y& Elsevier] |
| Copyright of Journal of Computational Physics is the property of Academic Press Inc. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 9054468 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: A time self-adaptive multilevel algorithm for large-eddy simulation – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Terracol%2C+M%2E%22">Terracol, M.</searchLink><relatesTo>1</relatesTo><i> terracol@onera.fr</i><br /><searchLink fieldCode="AR" term="%22Sagaut%2C+P%2E%22">Sagaut, P.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Basdevant%2C+C%2E%22">Basdevant, C.</searchLink><relatesTo>2</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Computational+Physics%22">Journal of Computational Physics</searchLink>. Jan2003, Vol. 184 Issue 2, p339. 27p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Simulation+methods+%26+models%22">Simulation methods & models</searchLink><br /><searchLink fieldCode="DE" term="%22Multilevel+models%22">Multilevel models</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: An extension of the multilevel method applied to LES proposed in Terracol et al. [J. Comput. Phys. 167 (2001) 439] is introduced here to reduce the CPU times in unsteady simulation of turbulent flows. Flow variables are decomposed into several wavenumber bands, each band being associated to a computational grid in physical space. The general framework associated to such a decomposition is presented, and a new adapted closure is proposed for the subgrid terms which appear at each filtering level, while the closure at the finest level is performed with a classical LES model. CPU time saving is obtained by the use of V-cycles, as in the multigrid terminology. The main part of the simulation is thus performed on the coarse levels, while the smallest resolved scales are kept frozen (quasi-static approximation [Comput. Methods Appl. Mech. Engrg. 159 (1998) 123]). This allows to reduce significantly the CPU times in comparison with classical LES, while the accuracy of the simulation is preserved by the use of a fine discretization level. To ensure the validity of the quasi-static approximation, a dynamic evaluation of the time during which it remains valid is performed at each level through an a priori error estimation of the small-scales time variation. This leads to a totally self-adaptive method in which both the number of levels and the integration times on each grid level are evaluated dynamically. The method is assessed on a fully unsteady time-developing compressible mixing layer at a low-Reynolds number for which a DNS has also been performed, and in the inviscid case. Finally, a plane channel flow configuration has been considered. In all cases, the results obtained are in good agreement with classical LES performed on a fine grid, with CPU time reduction factors of up to five. [Copyright &y& Elsevier] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Computational Physics is the property of Academic Press Inc. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/S0021-9991(02)00017-7 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 27 StartPage: 339 Subjects: – SubjectFull: Simulation methods & models Type: general – SubjectFull: Multilevel models Type: general Titles: – TitleFull: A time self-adaptive multilevel algorithm for large-eddy simulation Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Terracol, M. – PersonEntity: Name: NameFull: Sagaut, P. – PersonEntity: Name: NameFull: Basdevant, C. IsPartOfRelationships: – BibEntity: Dates: – D: 20 M: 01 Text: Jan2003 Type: published Y: 2003 Identifiers: – Type: issn-print Value: 00219991 Numbering: – Type: volume Value: 184 – Type: issue Value: 2 Titles: – TitleFull: Journal of Computational Physics Type: main |
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