View in EDS

Resonances and instabilities in a tilted rotating annulus.

Saved in:
Bibliographic Details
Title: Resonances and instabilities in a tilted rotating annulus.
Authors: Scollo, S.1 scollo@irphe.univ-mrs.fr, Nobili, C.1, Villermaux, E.1,2, Meunier, P.1
Source: Journal of Fluid Mechanics. 10/25/2023, Vol. 973, pA34-1-A34-29. 29p.
Subjects: Free surfaces, Surface forces, Turbulent flow, Turbulence, Resonance effect, Taylor vortices
Abstract: The flow inside a rotating annulus tilted with respect to gravity is characterized experimentally and theoretically. As in the case of a tilted rotating cylinder the flow is forced by the free surface, maintained flat by gravity. It leads to resonances of global inertial modes (Kelvin modes) when the height of fluid is a multiple of half the wavelength of the mode. The divergence of the mode is saturated by viscous effects at the resonance. The maximum amplitude scales as the Ekman number to the power -1/2 when surface Ekman pumping is dominant, and to the power -1 when volumic damping is dominant. An analytical prediction is given with no fitting parameter, in excellent agreement with experimental results. At lower Ekman numbers, the flow destabilizes with respect to a triadic resonance instability, as already observed by Xu & Harlander (Phys. Rev. Fluids, 2020). We provide here a linear stability analysis leading to the viscous threshold of the instability for small tilt angles. For large tilt angles, a centrifugal instability is observed due to the acceleration of the flow by the inner cylinder. Finally, the features of the turbulent flow and its mixing efficiency are characterized experimentally. We underline the potential interest of this configuration for bioreactors. [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
Header DbId: egs
DbLabel: Engineering Source
An: 173426483
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Resonances and instabilities in a tilted rotating annulus.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Scollo%2C+S%2E%22">Scollo, S.</searchLink><relatesTo>1</relatesTo><i> scollo@irphe.univ-mrs.fr</i><br /><searchLink fieldCode="AR" term="%22Nobili%2C+C%2E%22">Nobili, C.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Villermaux%2C+E%2E%22">Villermaux, E.</searchLink><relatesTo>1,2</relatesTo><br /><searchLink fieldCode="AR" term="%22Meunier%2C+P%2E%22">Meunier, P.</searchLink><relatesTo>1</relatesTo>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Journal+of+Fluid+Mechanics%22">Journal of Fluid Mechanics</searchLink>. 10/25/2023, Vol. 973, pA34-1-A34-29. 29p.
– Name: Subject
  Label: Subjects
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Free+surfaces%22">Free surfaces</searchLink><br /><searchLink fieldCode="DE" term="%22Surface+forces%22">Surface forces</searchLink><br /><searchLink fieldCode="DE" term="%22Turbulent+flow%22">Turbulent flow</searchLink><br /><searchLink fieldCode="DE" term="%22Turbulence%22">Turbulence</searchLink><br /><searchLink fieldCode="DE" term="%22Resonance+effect%22">Resonance effect</searchLink><br /><searchLink fieldCode="DE" term="%22Taylor+vortices%22">Taylor vortices</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: The flow inside a rotating annulus tilted with respect to gravity is characterized experimentally and theoretically. As in the case of a tilted rotating cylinder the flow is forced by the free surface, maintained flat by gravity. It leads to resonances of global inertial modes (Kelvin modes) when the height of fluid is a multiple of half the wavelength of the mode. The divergence of the mode is saturated by viscous effects at the resonance. The maximum amplitude scales as the Ekman number to the power -1/2 when surface Ekman pumping is dominant, and to the power -1 when volumic damping is dominant. An analytical prediction is given with no fitting parameter, in excellent agreement with experimental results. At lower Ekman numbers, the flow destabilizes with respect to a triadic resonance instability, as already observed by Xu & Harlander (Phys. Rev. Fluids, 2020). We provide here a linear stability analysis leading to the viscous threshold of the instability for small tilt angles. For large tilt angles, a centrifugal instability is observed due to the acceleration of the flow by the inner cylinder. Finally, the features of the turbulent flow and its mixing efficiency are characterized experimentally. We underline the potential interest of this configuration for bioreactors. [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.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=173426483
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1017/jfm.2023.754
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 29
        StartPage: A34-1
    Subjects:
      – SubjectFull: Free surfaces
        Type: general
      – SubjectFull: Surface forces
        Type: general
      – SubjectFull: Turbulent flow
        Type: general
      – SubjectFull: Turbulence
        Type: general
      – SubjectFull: Resonance effect
        Type: general
      – SubjectFull: Taylor vortices
        Type: general
    Titles:
      – TitleFull: Resonances and instabilities in a tilted rotating annulus.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Scollo, S.
      – PersonEntity:
          Name:
            NameFull: Nobili, C.
      – PersonEntity:
          Name:
            NameFull: Villermaux, E.
      – PersonEntity:
          Name:
            NameFull: Meunier, P.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 25
              M: 10
              Text: 10/25/2023
              Type: published
              Y: 2023
          Identifiers:
            – Type: issn-print
              Value: 00221120
          Numbering:
            – Type: volume
              Value: 973
          Titles:
            – TitleFull: Journal of Fluid Mechanics
              Type: main
ResultId 1