Persistent Non-Homogeneous Features in Periodic Channel-Flow Simulations.
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| Title: | Persistent Non-Homogeneous Features in Periodic Channel-Flow Simulations. |
|---|---|
| Authors: | G. Fishpool1, S. Lardeau1, M. Leschziner1 |
| Source: | Flow, Turbulence & Combustion. Oct2009, Vol. 83 Issue 3, p323-342. 20p. |
| Subjects: | Shear flow, Boundary layer (Aerodynamics), Turbulence, Fluid dynamics, Statistics, Fluid mechanics, Simulation methods & models |
| Abstract: | Abstract Time-resolved simulations of simple shear flows, such as boundary layers and channel flows, are often used as precursor simulations that provide the inflow-boundary conditions for simulations of turbulent flows in and around more complex geometries. For both the precursor and main simulations, the accuracy of the calculated mean flow relies on the simulations being run for long enough to contain the full spectrum of turbulent processes, resulting in a physically valid statistical representation. The time scale needed to achieve convergence of statistics from fundamental studies of simple shear flows is based on data that is averaged in spatial directions in which the flow geometry is invariant—i.e. directions in which homogeneity is expected to be the limiting case. This paper reports and discusses features that represent significant departures from spatial homogeneity of the flow in such a direction, that persist on this time scale, thereby limiting the spatial uniformity of a simulated turbulent inflow. The persistence and size of the features is quantified. A range of simulations for different combinations of domain dimensions and flow parameters has been performed with two independent codes (DNS and LES) to explore how the persistence and size are controlled. While no definitive physical mechanism has been identified, it is suggested that the features may be related to experimental observations of persistent structures in wall-bounded flows. [ABSTRACT FROM AUTHOR] |
| Copyright of Flow, Turbulence & Combustion is the property of Springer Nature 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: 44730285 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Persistent Non-Homogeneous Features in Periodic Channel-Flow Simulations. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22G%2E+Fishpool%22">G. Fishpool</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22S%2E+Lardeau%22">S. Lardeau</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22M%2E+Leschziner%22">M. Leschziner</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Flow%2C+Turbulence+%26+Combustion%22">Flow, Turbulence & Combustion</searchLink>. Oct2009, Vol. 83 Issue 3, p323-342. 20p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Shear+flow%22">Shear flow</searchLink><br /><searchLink fieldCode="DE" term="%22Boundary+layer+%28Aerodynamics%29%22">Boundary layer (Aerodynamics)</searchLink><br /><searchLink fieldCode="DE" term="%22Turbulence%22">Turbulence</searchLink><br /><searchLink fieldCode="DE" term="%22Fluid+dynamics%22">Fluid dynamics</searchLink><br /><searchLink fieldCode="DE" term="%22Statistics%22">Statistics</searchLink><br /><searchLink fieldCode="DE" term="%22Fluid+mechanics%22">Fluid mechanics</searchLink><br /><searchLink fieldCode="DE" term="%22Simulation+methods+%26+models%22">Simulation methods & models</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Abstract  Time-resolved simulations of simple shear flows, such as boundary layers and channel flows, are often used as precursor simulations that provide the inflow-boundary conditions for simulations of turbulent flows in and around more complex geometries. For both the precursor and main simulations, the accuracy of the calculated mean flow relies on the simulations being run for long enough to contain the full spectrum of turbulent processes, resulting in a physically valid statistical representation. The time scale needed to achieve convergence of statistics from fundamental studies of simple shear flows is based on data that is averaged in spatial directions in which the flow geometry is invariant—i.e. directions in which homogeneity is expected to be the limiting case. This paper reports and discusses features that represent significant departures from spatial homogeneity of the flow in such a direction, that persist on this time scale, thereby limiting the spatial uniformity of a simulated turbulent inflow. The persistence and size of the features is quantified. A range of simulations for different combinations of domain dimensions and flow parameters has been performed with two independent codes (DNS and LES) to explore how the persistence and size are controlled. While no definitive physical mechanism has been identified, it is suggested that the features may be related to experimental observations of persistent structures in wall-bounded flows. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Flow, Turbulence & Combustion is the property of Springer Nature 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: 10.1007/s10494-009-9209-z Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 20 StartPage: 323 Subjects: – SubjectFull: Shear flow Type: general – SubjectFull: Boundary layer (Aerodynamics) Type: general – SubjectFull: Turbulence Type: general – SubjectFull: Fluid dynamics Type: general – SubjectFull: Statistics Type: general – SubjectFull: Fluid mechanics Type: general – SubjectFull: Simulation methods & models Type: general Titles: – TitleFull: Persistent Non-Homogeneous Features in Periodic Channel-Flow Simulations. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: G. Fishpool – PersonEntity: Name: NameFull: S. Lardeau – PersonEntity: Name: NameFull: M. Leschziner IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 10 Text: Oct2009 Type: published Y: 2009 Identifiers: – Type: issn-print Value: 13866184 Numbering: – Type: volume Value: 83 – Type: issue Value: 3 Titles: – TitleFull: Flow, Turbulence & Combustion Type: main |
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