Gravity modulation of thermal instability in a viscoelastic fluid saturated anisotropic porous medium

Beer S. Bhadauria, Atul K. Srivastava, Nirmal C. Sacheti, Pallath Chandran

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The present paper deals with a thermal instability problem in a viscoelastic fluid saturating an anisotropic porous medium under gravity modulation. To find the gravity modulation effect, the gravity field is considered in two parts: a constant part and an externally imposed time-dependent periodic part. The time-dependent part of the gravity field, which can be realized by shaking the fluid, has been represented by a sinusoidal function. Using Hill's equation and the Floquet theory, the convective threshold has been obtained. It is found that gravity modulation can significantly affect the stability limits of the system. Further, we find that there is a competition between the synchronous and subharmonic modes of convection at the onset of instability. Effects of various parameters on the onset of instability have also been discussed.

Original languageEnglish
Pages (from-to)1-9
Number of pages9
JournalZeitschrift fur Naturforschung - Section A Journal of Physical Sciences
Volume67
Issue number1-2
DOIs
Publication statusPublished - 2012

Fingerprint

thermal instability
Viscoelastic Fluid
Porous Media
Porous materials
Gravity
Gravitation
Modulation
gravitation
modulation
Fluids
fluids
Hill Equation
Floquet Theory
shaking
Subharmonics
Convection
convection
Hot Temperature
Fluid
thresholds

Keywords

  • Anisotropic porous
  • Gravity modulation
  • Thermal rayleigh number
  • Viscoelastic fluid

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Mathematical Physics
  • Physics and Astronomy(all)

Cite this

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AU - Bhadauria, Beer S.

AU - Srivastava, Atul K.

AU - Sacheti, Nirmal C.

AU - Chandran, Pallath

PY - 2012

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N2 - The present paper deals with a thermal instability problem in a viscoelastic fluid saturating an anisotropic porous medium under gravity modulation. To find the gravity modulation effect, the gravity field is considered in two parts: a constant part and an externally imposed time-dependent periodic part. The time-dependent part of the gravity field, which can be realized by shaking the fluid, has been represented by a sinusoidal function. Using Hill's equation and the Floquet theory, the convective threshold has been obtained. It is found that gravity modulation can significantly affect the stability limits of the system. Further, we find that there is a competition between the synchronous and subharmonic modes of convection at the onset of instability. Effects of various parameters on the onset of instability have also been discussed.

AB - The present paper deals with a thermal instability problem in a viscoelastic fluid saturating an anisotropic porous medium under gravity modulation. To find the gravity modulation effect, the gravity field is considered in two parts: a constant part and an externally imposed time-dependent periodic part. The time-dependent part of the gravity field, which can be realized by shaking the fluid, has been represented by a sinusoidal function. Using Hill's equation and the Floquet theory, the convective threshold has been obtained. It is found that gravity modulation can significantly affect the stability limits of the system. Further, we find that there is a competition between the synchronous and subharmonic modes of convection at the onset of instability. Effects of various parameters on the onset of instability have also been discussed.

KW - Anisotropic porous

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