Weakly nonlinear viscoplastic convection

Saved in:
Bibliographic Details
Title: Weakly nonlinear viscoplastic convection
Authors: Balmforth, Neil J.1,2, Rust, Alison C.3 Alison.Rust@bristol.ac.uk
Source: Journal of Non-Newtonian Fluid Mechanics. May2009, Vol. 158 Issue 1-3, p36-45. 10p.
Subjects: Heat convection, Viscoplasticity, Viscous flow, Rayleigh number, Newtonian fluids, Shear (Mechanics), Viscosity
Abstract: Abstract: The development of thermal convection is studied for a viscoplastic fluid. If the viscosity is finite at zero shear rate, the critical Rayleigh number for linear instability takes the value given by a Newtonian fluid with that viscosity. The subsequent weakly nonlinear behaviour depends on the degree of shear thinning: with moderate shear thinning, convective overturning for a given temperature difference is amplified relative to the Newtonian case. If the reduction in viscosity is sufficiently sharp the transition becomes subcritical (the relevant situation for many regularized constitutive laws). For an infinite viscosity at zero shear rate, or a yield-stress, the critical Rayleigh number for linear instability is infinite. Nonlinear convective overturning, however, is still possible; we trace out how the finite-amplitude solution branches develop from their Newtonian counterparts as the yield stress is increased from zero for the Bingham fluid. Laboratory experiments with a layer of Carbopol fluid heated from below confirm that yield strength inhibits convection but a sufficiently strong perturbation can initiate overturning. [Copyright &y& Elsevier]
Copyright of Journal of Non-Newtonian Fluid Mechanics is the property of Elsevier B.V. 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: 37229414
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Weakly nonlinear viscoplastic convection
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Balmforth%2C+Neil+J%2E%22">Balmforth, Neil J.</searchLink><relatesTo>1,2</relatesTo><br /><searchLink fieldCode="AR" term="%22Rust%2C+Alison+C%2E%22">Rust, Alison C.</searchLink><relatesTo>3</relatesTo><i> Alison.Rust@bristol.ac.uk</i>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Journal+of+Non-Newtonian+Fluid+Mechanics%22">Journal of Non-Newtonian Fluid Mechanics</searchLink>. May2009, Vol. 158 Issue 1-3, p36-45. 10p.
– Name: Subject
  Label: Subjects
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Heat+convection%22">Heat convection</searchLink><br /><searchLink fieldCode="DE" term="%22Viscoplasticity%22">Viscoplasticity</searchLink><br /><searchLink fieldCode="DE" term="%22Viscous+flow%22">Viscous flow</searchLink><br /><searchLink fieldCode="DE" term="%22Rayleigh+number%22">Rayleigh number</searchLink><br /><searchLink fieldCode="DE" term="%22Newtonian+fluids%22">Newtonian fluids</searchLink><br /><searchLink fieldCode="DE" term="%22Shear+%28Mechanics%29%22">Shear (Mechanics)</searchLink><br /><searchLink fieldCode="DE" term="%22Viscosity%22">Viscosity</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: Abstract: The development of thermal convection is studied for a viscoplastic fluid. If the viscosity is finite at zero shear rate, the critical Rayleigh number for linear instability takes the value given by a Newtonian fluid with that viscosity. The subsequent weakly nonlinear behaviour depends on the degree of shear thinning: with moderate shear thinning, convective overturning for a given temperature difference is amplified relative to the Newtonian case. If the reduction in viscosity is sufficiently sharp the transition becomes subcritical (the relevant situation for many regularized constitutive laws). For an infinite viscosity at zero shear rate, or a yield-stress, the critical Rayleigh number for linear instability is infinite. Nonlinear convective overturning, however, is still possible; we trace out how the finite-amplitude solution branches develop from their Newtonian counterparts as the yield stress is increased from zero for the Bingham fluid. Laboratory experiments with a layer of Carbopol fluid heated from below confirm that yield strength inhibits convection but a sufficiently strong perturbation can initiate overturning. [Copyright &y& Elsevier]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Journal of Non-Newtonian Fluid Mechanics is the property of Elsevier B.V. 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=37229414
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1016/j.jnnfm.2008.07.012
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 10
        StartPage: 36
    Subjects:
      – SubjectFull: Heat convection
        Type: general
      – SubjectFull: Viscoplasticity
        Type: general
      – SubjectFull: Viscous flow
        Type: general
      – SubjectFull: Rayleigh number
        Type: general
      – SubjectFull: Newtonian fluids
        Type: general
      – SubjectFull: Shear (Mechanics)
        Type: general
      – SubjectFull: Viscosity
        Type: general
    Titles:
      – TitleFull: Weakly nonlinear viscoplastic convection
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Balmforth, Neil J.
      – PersonEntity:
          Name:
            NameFull: Rust, Alison C.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 05
              Text: May2009
              Type: published
              Y: 2009
          Identifiers:
            – Type: issn-print
              Value: 03770257
          Numbering:
            – Type: volume
              Value: 158
            – Type: issue
              Value: 1-3
          Titles:
            – TitleFull: Journal of Non-Newtonian Fluid Mechanics
              Type: main
ResultId 1