Weakly nonlinear convective regimes in a horizontal fluid layer with poorly conducting boundaries and temperature-dependent viscosity

2016 ◽  
Vol 59 ◽  
pp. 70-85 ◽  
Author(s):  
E.S. Sadilov ◽  
D.V. Lyubimov
Keyword(s):  
Fluid Layer ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Weakly Nonlinear ◽  
Dependent Viscosity ◽  
Horizontal Fluid Layer

Rolls versus squares in thermal convection of fluids with temperature-dependent viscosity

1987 ◽  
Vol 178 ◽  
pp. 491-506 ◽  
Author(s):  
D. R. Jenkins
Keyword(s):  
Thermal Convection ◽  
Fluid Layer ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Finite Amplitude ◽  
Temperature Dependent Viscosity ◽  
Weakly Nonlinear ◽  
Expansion Procedure ◽  
The Stability ◽  
Dependent Viscosity

We consider finite-amplitude thermal convection, in a horizontal fluid layer. The viscosity of the fluid is dependent upon its temperature. Using a weakly nonlinear expansion procedure, we examine the stability of two-dimensional roll and three-dimensional square planforms, in order to determine which should be preferred in convection experiments. The analysis shows that the roll planform is preferred for low values of the ratio of the viscosities at the top and bottom boundaries, but the square planform is preferred for larger values of the ratio. At still larger values, subcritical convection is predicted. We also include the effects of boundaries having finite thermal conductivity, which enables favourable comparison to be made with experimental studies. A discrepancy between the present work and a previous study of this problem (Busse & Frick 1985) is discussed.

scholarly journals Effect of Soret and Temperature Dependent Viscosity on Thermohaline Convection in a Ferrofluid Saturating a Porous Medium

2014 ◽  
Vol 19 (2) ◽  
pp. 321-336
Author(s):  
R. Sekar ◽  
K. Raju
Keyword(s):  
Porous Medium ◽  
Fluid Layer ◽  
Effect Of Temperature ◽  
Stationary Mode ◽  
Free Boundaries ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Onset Of Convection ◽  
Wide Range ◽  
Dependent Viscosity

Abstract Soret driven ferrothermoconvective instability in multi-component fluids has a wide range of applications in heat and mass transfer. This paper deals with the theoretical investigation of the effect of temperature dependent viscosity on a Soret driven ferrothermohaline convection heated from below and salted from above subjected to a transverse uniform magnetic field in the presence of a porous medium. The Brinkman model is used in the study. It is found that the stationary mode of instability is preferred. For a horizontal fluid layer contained between two free boundaries an exact solution is examined using the normal mode technique for a linear stability analysis. The effect of salinity has been included in magnetization and density of the fluid. The critical thermal magnetic Rayleigh number for the onset of instability is obtained numerically for sufficiently large values of the buoyancy magnetization parameter M1 using the method of numerical Galerkin technique. It is found that magnetization and permeability of the porous medium destabilize the system. The effect of temperature dependent viscosity stabilizes the system on the onset of convection.

scholarly journals Surface deformation on thermocapillary convection in a binary fluid with internal heat generation and temperature dependent viscosity

2018 ◽  
Vol 7 (2.15) ◽  
pp. 86
Author(s):  
Nurul Hafizah Zainal Abidin ◽  
Nor Fadzillah Mohd Mokhtar ◽  
Nur Zarifah Abdul Hamid ◽  
Zanariah Abdul Majid
Keyword(s):  
Heat Generation ◽  
Thermocapillary Convection ◽  
Surface Deformation ◽  
Fluid Layer ◽  
Internal Heat ◽  
Internal Heat Generation ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Binary Fluid ◽  
Dependent Viscosity

The effects of temperature dependent viscosity and internal heat generation on the onset of steady Bénard-Marangoni convection in a horizontal binary fluid layer heated from below is investigated theoretically. The upper free surface is assumed to be deformable and the lower boundary is considered to be rigid and perfectly insulated to temperature perturbations. The asymptotic solution of the long wavelength is obtained using regular perturbation method with wave number as a perturbation parameter. It is found that the surface deformation of a binary fluid layer enhances the onset of thermocapillary convection while increasing the value of internal heat generation and temperature dependent viscosity will destabilize the binary fluid layer system. 

Square-pattern convection in fluids with strongly temperature-dependent viscosity

1985 ◽  
Vol 150 ◽  
pp. 451-465 ◽  
Author(s):  
F. H. Busse ◽  
H. Frick
Keyword(s):  
Numerical Solutions ◽  
Fluid Layer ◽  
Three Dimensional ◽  
Square Lattice ◽  
Two Dimensional ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
The Stability ◽  
Dependent Viscosity ◽  
Theoretical Results

Three-dimensional numerical solutions are obtained describing convection with a square lattice in a layer heated from below with no-slip top and bottom boundaries. The limit of infinite Prandtl number and a linear dependence of the viscosity on temperature are assumed. The stability of the three-dimensional solutions with respect to disturbances fitting the square lattice is analysed. It is shown that convection in the form of two-dimensional rolls is stable for low variations of viscosity, while square-pattern convection becomes stable when the viscosity contrast between upper and lower parts of the fluid layer is sufficiently strong. The theoretical results are in qualitative agreement with experimental observations.

scholarly journals Onset of Benard-Marangoni instabilities in a double diffusive binary fluid layer with temperature-dependent viscosity

2019 ◽  
Vol 9 (4) ◽  
pp. 413-421
Author(s):  
Nurul Hafizah Zainal Abidin ◽  
◽  
Nor Fadzillah Mohd Mokhtar ◽  
Zanariah Abdul Majid ◽  
◽  
...  
Keyword(s):  
Fluid Layer ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Binary Fluid ◽  
Dependent Viscosity ◽  
Double Diffusive
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