Temperature dependent viscosity effect on stability convection of double diffusive binary fluid

In this thesis, the thermal instability in a double diffusive binary fluid with temperature dependent viscosity effect is formulated mathematically based on Boussinesq approximation. The linear stability analysis is applied to the governing equations. The resulting eigenvalue obtained are solved...

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Main Author:	Zainal Abidin, Nurul Hafizah
Format:	Thesis
Language:	English
Published:	2019
Subjects:	Heat - Convection Thermal diffusivity Fluid mechanics
Online Access:	http://psasir.upm.edu.my/id/eprint/90346/1/IPM%202020%204%20ir.pdf
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spelling	my-upm-ir.903462021-12-01T06:46:22Z Temperature dependent viscosity effect on stability convection of double diffusive binary fluid 2019-10 Zainal Abidin, Nurul Hafizah In this thesis, the thermal instability in a double diffusive binary fluid with temperature dependent viscosity effect is formulated mathematically based on Boussinesq approximation. The linear stability analysis is applied to the governing equations. The resulting eigenvalue obtained are solved numerically using single-term Galerkin method with respect to different velocities and temperature conditions. The systems considered in this analysis are designed in one fluid layer system or saturated in an anisotropic porous medium. The mathematical model is then extended in a viscoelastic fluid where the oscillatory mode was presented. The Darcy model is used to describe the flow regime in the porous medium while the Oldroyd model is implemented for the viscoelastic fluid. The impact of temperature dependent viscosity, double diffusive coefficients, vertical magnetic field, feedback control, Coriolis force, and internal heat generation, anisotropic and viscoelastic parameters on the onset of Rayleigh-B´enard in the system are analyzed and presented graphically. It is found that an increase of the temperature dependent viscosity, Soret number, Lewis number always delayed the onset of convection in the system, meanwhile elevating the effects of vertical magnetic field, Dufour number, Coriolis force, feedback control, and solutal Rayleigh number hastened the instability of the system. For the effect of mechanical anisotropic on the porous medium, results show that the mechanical anisotropy destabilizes the system while the thermal anisotropy stabilizes the porous system. The effect of stress relaxation and strain retardation in the oscillatory mode of convection in the viscoelastic fluid were also discussed. Findings revealed that the critical Rayleigh-B´enard increased as the stress relaxation decreased and strain retardation increased. Heat - Convection Thermal diffusivity Fluid mechanics 2019-10 Thesis http://psasir.upm.edu.my/id/eprint/90346/ http://psasir.upm.edu.my/id/eprint/90346/1/IPM%202020%204%20ir.pdf text en public doctoral Universiti Putra Malaysia Heat - Convection Thermal diffusivity Fluid mechanics Mohd Mokhtar, Nor Fadzillah
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English
advisor	Mohd Mokhtar, Nor Fadzillah
topic	Heat - Convection Thermal diffusivity Fluid mechanics
spellingShingle	Heat - Convection Thermal diffusivity Fluid mechanics Zainal Abidin, Nurul Hafizah Temperature dependent viscosity effect on stability convection of double diffusive binary fluid
description	In this thesis, the thermal instability in a double diffusive binary fluid with temperature dependent viscosity effect is formulated mathematically based on Boussinesq approximation. The linear stability analysis is applied to the governing equations. The resulting eigenvalue obtained are solved numerically using single-term Galerkin method with respect to different velocities and temperature conditions. The systems considered in this analysis are designed in one fluid layer system or saturated in an anisotropic porous medium. The mathematical model is then extended in a viscoelastic fluid where the oscillatory mode was presented. The Darcy model is used to describe the flow regime in the porous medium while the Oldroyd model is implemented for the viscoelastic fluid. The impact of temperature dependent viscosity, double diffusive coefficients, vertical magnetic field, feedback control, Coriolis force, and internal heat generation, anisotropic and viscoelastic parameters on the onset of Rayleigh-B´enard in the system are analyzed and presented graphically. It is found that an increase of the temperature dependent viscosity, Soret number, Lewis number always delayed the onset of convection in the system, meanwhile elevating the effects of vertical magnetic field, Dufour number, Coriolis force, feedback control, and solutal Rayleigh number hastened the instability of the system. For the effect of mechanical anisotropic on the porous medium, results show that the mechanical anisotropy destabilizes the system while the thermal anisotropy stabilizes the porous system. The effect of stress relaxation and strain retardation in the oscillatory mode of convection in the viscoelastic fluid were also discussed. Findings revealed that the critical Rayleigh-B´enard increased as the stress relaxation decreased and strain retardation increased.
format	Thesis
qualification_level	Doctorate
author	Zainal Abidin, Nurul Hafizah
author_facet	Zainal Abidin, Nurul Hafizah
author_sort	Zainal Abidin, Nurul Hafizah
title	Temperature dependent viscosity effect on stability convection of double diffusive binary fluid
title_short	Temperature dependent viscosity effect on stability convection of double diffusive binary fluid
title_full	Temperature dependent viscosity effect on stability convection of double diffusive binary fluid
title_fullStr	Temperature dependent viscosity effect on stability convection of double diffusive binary fluid
title_full_unstemmed	Temperature dependent viscosity effect on stability convection of double diffusive binary fluid
title_sort	temperature dependent viscosity effect on stability convection of double diffusive binary fluid
granting_institution	Universiti Putra Malaysia
publishDate	2019
url	http://psasir.upm.edu.my/id/eprint/90346/1/IPM%202020%204%20ir.pdf
_version_	1747813615605383168

Temperature dependent viscosity effect on stability convection of double diffusive binary fluid

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