A spatially accelerating turbulent flow with longitudinally contracting walls.
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| Title: | A spatially accelerating turbulent flow with longitudinally contracting walls. |
|---|---|
| Authors: | Falcone, M.1 (AUTHOR), He, S.1 (AUTHOR) s.he@sheffield.ac.uk |
| Source: | Journal of Fluid Mechanics. 8/25/2022, Vol. 945, p1-38. 38p. |
| Subjects: | Turbulence, Turbulent flow, Flow simulations, Turbulent boundary layer, Transition flow, Boundary layer (Aerodynamics) |
| Abstract: | This paper describes a study of spatially accelerating turbulent flow based on the direct numerical simulation of a flow with longitudinally accelerating moving walls to create a relative acceleration between the fluid and the wall without inducing streamline curvature. The results show a broad similarity to those of previous investigations of spatial acceleration, albeit with some differences. A new interpretation has been proposed considering this spatially accelerating flow to be characterised by the formation of a new boundary layer superimposed on the pre-existing turbulent flow. This is followed by the transition of the flow in response to the development of this new boundary layer. This can be seen as an extension of the transition theory for temporally accelerating turbulent flows (He & Seddighi, J. Fluid Mech., vol. 715, 2013, pp. 60–102). The existing turbulent structures act as disturbances for the new boundary layer similar to the role of free-stream turbulence in bypass transition. This boundary layer modulates the pre-existing near-wall structures, amplifying and elongating the streaks. Some streaks eventually become unstable in a sinuous mechanism reminiscent of streak breakdown in near-wall turbulence, resulting in the formation localised turbulent spots which spread until the entire wall is covered in new turbulence. This interpretation naturally splits the flow into a new boundary layer region and a core (or free-stream) flow with interactions between the two dominating a significant length of the flow development and potentially offers a new explanation for the slow evolution of the turbulent stresses observed previously. [ABSTRACT FROM AUTHOR] |
| Copyright of Journal of Fluid Mechanics is the property of Cambridge University Press 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: 159190981 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: A spatially accelerating turbulent flow with longitudinally contracting walls. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Falcone%2C+M%2E%22">Falcone, M.</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22He%2C+S%2E%22">He, S.</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> s.he@sheffield.ac.uk</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Fluid+Mechanics%22">Journal of Fluid Mechanics</searchLink>. 8/25/2022, Vol. 945, p1-38. 38p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Turbulence%22">Turbulence</searchLink><br /><searchLink fieldCode="DE" term="%22Turbulent+flow%22">Turbulent flow</searchLink><br /><searchLink fieldCode="DE" term="%22Flow+simulations%22">Flow simulations</searchLink><br /><searchLink fieldCode="DE" term="%22Turbulent+boundary+layer%22">Turbulent boundary layer</searchLink><br /><searchLink fieldCode="DE" term="%22Transition+flow%22">Transition flow</searchLink><br /><searchLink fieldCode="DE" term="%22Boundary+layer+%28Aerodynamics%29%22">Boundary layer (Aerodynamics)</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: This paper describes a study of spatially accelerating turbulent flow based on the direct numerical simulation of a flow with longitudinally accelerating moving walls to create a relative acceleration between the fluid and the wall without inducing streamline curvature. The results show a broad similarity to those of previous investigations of spatial acceleration, albeit with some differences. A new interpretation has been proposed considering this spatially accelerating flow to be characterised by the formation of a new boundary layer superimposed on the pre-existing turbulent flow. This is followed by the transition of the flow in response to the development of this new boundary layer. This can be seen as an extension of the transition theory for temporally accelerating turbulent flows (He & Seddighi, J. Fluid Mech., vol. 715, 2013, pp. 60–102). The existing turbulent structures act as disturbances for the new boundary layer similar to the role of free-stream turbulence in bypass transition. This boundary layer modulates the pre-existing near-wall structures, amplifying and elongating the streaks. Some streaks eventually become unstable in a sinuous mechanism reminiscent of streak breakdown in near-wall turbulence, resulting in the formation localised turbulent spots which spread until the entire wall is covered in new turbulence. This interpretation naturally splits the flow into a new boundary layer region and a core (or free-stream) flow with interactions between the two dominating a significant length of the flow development and potentially offers a new explanation for the slow evolution of the turbulent stresses observed previously. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Fluid Mechanics is the property of Cambridge University Press 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: 10.1017/jfm.2022.560 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 38 StartPage: 1 Subjects: – SubjectFull: Turbulence Type: general – SubjectFull: Turbulent flow Type: general – SubjectFull: Flow simulations Type: general – SubjectFull: Turbulent boundary layer Type: general – SubjectFull: Transition flow Type: general – SubjectFull: Boundary layer (Aerodynamics) Type: general Titles: – TitleFull: A spatially accelerating turbulent flow with longitudinally contracting walls. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Falcone, M. – PersonEntity: Name: NameFull: He, S. IsPartOfRelationships: – BibEntity: Dates: – D: 25 M: 08 Text: 8/25/2022 Type: published Y: 2022 Identifiers: – Type: issn-print Value: 00221120 Numbering: – Type: volume Value: 945 Titles: – TitleFull: Journal of Fluid Mechanics Type: main |
| ResultId | 1 |
