Thermosolutal Convection in a Couple-Stress Fluid in Uniform Vertical Magnetic Field

2012 ◽  
Vol 67 (5) ◽  
pp. 275-281
Author(s):  
Mahinder Singh ◽  
Pardeep Kumar
Keyword(s):  
Magnetic Field ◽  
Couple Stress ◽  
Thermosolutal Convection ◽  
Couple Stress Fluid ◽  
Vertical Magnetic Field ◽  
Stationary Convection ◽  
Gradient Magnetic Field ◽  
Electrically Conducting ◽  
Stabilizing Effect ◽  
Solute Gradient

The effect of a uniform vertical magnetic field on thermosolutal convection in a layer of an electrically conducting couple-stress fluid heated and soluted from below is considered. For the case of stationary convection, the stable solute gradient, magnetic field, and couple-stress parameter have stabilizing effect on the system. It is also observed that a stable solute gradient and a magnetic field introduce oscillatory modes in the system, but in the absence of a stable solute gradient and a magnetic field, oscillatory modes are not allowed and the principle of exchange of stabilities is valid.

Rotatory Thermosolutal Convection in a Couple-Stress Fluid

2009 ◽  
Vol 64 (7-8) ◽  
pp. 448-454
Author(s):  
Pardeep Kumar ◽  
Mahinder Singh
Keyword(s):  
Dispersion Relation ◽  
Couple Stress ◽  
Normal Mode Analysis ◽  
Sufficient Conditions ◽  
Thermosolutal Convection ◽  
Mode Analysis ◽  
Couple Stress Fluid ◽  
Stationary Convection ◽  
Linearized Stability ◽  
Solute Gradient

AbstractThe thermosolutal instability of couple-stress fluid in the presence of uniform vertical rotation is considered. Following the linearized stability theory and normal mode analysis, the dispersion is obtained. For the case of stationary convection, the stable solute gradient and rotation have stabilizing effects on the system, whereas the couple-stress has both stabilizing and destabilizing effects. The dispersion relation is also analyzed numerically. The stable solute gradient and the rotation introduce oscillatory modes in the system, which did not occur in their absence. The sufficient conditions for the non-existence of overstability are also obtained.

Effect of rotation on dusty couple-stress fluid with hydromagnetic field heated below through porous medium

2018 ◽  
Vol 15 (1) ◽  
pp. 148-155
Author(s):  
W. Stanly ◽  
R. Vasanthakumari
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Couple Stress ◽  
Perturbation Technique ◽  
Dust Particles ◽  
Couple Stress Fluid ◽  
Content Type ◽  
Medium Permeability ◽  
Stabilizing Effect ◽  
Solute Gradient

Purpose The purpose of this paper is used to study the combined effect of solute gradient and magnetic field on dusty couple-stress fluid in the presence of rotation through a porous medium. Design/methodology/approach The perturbation technique (experimental method) is applied in this study. Findings For the case of stationary convection, solute gradient and rotation have stabilizing effect, whereas destabilizing effect is found in dust particles in the system. Couple stress and medium permeability both have dual character to its stabilizing effect in the absence of magnetic field and rotation. Magnetic field succeeded in establishing a stabilizing effect in the absence of rotation. Originality/value The results are discussed by allowing one variable to vary and keeping other variables constant, as well as by drawing graphs.

scholarly journals Effect of hall currents on thermal instability of dusty couple stress fluid

2016 ◽  
Vol 37 (3) ◽  
pp. 3-18 ◽  
Author(s):  
Amrish Kumar Aggarwal ◽  
Anushri Verma
Keyword(s):  
Magnetic Field ◽  
Couple Stress ◽  
Thermal Instability ◽  
Normal Mode Analysis ◽  
Mode Analysis ◽  
Dust Particles ◽  
Couple Stress Fluid ◽  
Stationary Convection ◽  
Linearized Stability ◽  
Stabilizing Effect

Abstract In this paper, effect of Hall currents on the thermal instability of couple-stress fluid permeated with dust particles has been considered. Following the linearized stability theory and normal mode analysis, the dispersion relation is obtained. For the case of stationary convection, dust particles and Hall currents are found to have destabilizing effect while couple stresses have stabilizing effect on the system. Magnetic field induced by Hall currents has stabilizing/destabilizing effect under certain conditions. It is found that due to the presence of Hall currents (hence magnetic field), oscillatory modes are produced which were non-existent in their absence.

Double-Diffusive Magneto Convection in a Compressible Couple-Stress Fluid Through Porous Medium

2011 ◽  
Vol 66 (5) ◽  
pp. 304-310 ◽  
Author(s):  
Pardeep Kumar ◽  
Hari Mohan
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Couple Stress ◽  
Mode Analysis ◽  
Couple Stress Fluid ◽  
Onset Of Convection ◽  
Linearized Stability ◽  
Medium Permeability ◽  
Solute Gradient ◽  
Double Diffusive

The double-diffusive convection in a compressible couple-stress fluid layer heated and soluted from below through porous medium is considered in the presence of a uniform vertical magnetic field. Following the linearized stability theory and normal mode analysis, the dispersion relation is obtained. For stationary convection, the compressibility, stable solute gradient, magnetic field, and couple-stress postpone the onset of convection whereas medium permeability hastens the onset of convection. Graphs have been plotted by giving numerical values to the parameters to depict the stability characteristics. The stable solute gradient and magnetic field introduce oscillatory modes in the system, which were non-existent in their absence. A condition for the system to be stable is obtained by using the Rayleigh-Ritz inequality. The sufficient conditions for the non-existence of overstability are also obtained.

Effects of Mixed Convection on the Oscillatory Flow of a Couple Stress Fluid through a Vertical Plate with Variable Fluid Properties

2018 ◽  
Vol 388 ◽  
pp. 328-343
Author(s):  
R. Suresh Babu ◽  
B. Rushi Kumar ◽  
P.A. Dinesh
Keyword(s):  
Magnetic Field ◽  
Couple Stress ◽  
Vertical Plate ◽  
Couple Stress Fluid ◽  
Electrically Conducting ◽  
Coupled Equations ◽  
Variable Permeability ◽  
Variable Fluid Properties ◽  
Fluid Properties ◽  
Dimensional Parameters

A numerical computation has been carriedout for the steady, mixed convective, incompressible, viscous, electrically conducting couple stress fluid through a vertical plate with variable fluid properties in a porous medium. A uniform magnetic field is applied in the transverse direction and parallel to the vertical plate of the physical model and governing equations are derived for it."Using a suitable similarity transformation, governed PDE's are transformed into a set of ODE's which are highly non-linear coupled equations. An advanced Shooting technique is adopted to compute the variations of velocity, temperature, concentration in terms of non-dimensional parameters. Also physical interpretation of non-dimensional parameters like couple stress parameter magnetic field Prandtl number Schmidt number thermal conductivity and solutal diffusivity parameters are examined through plots for both variable permeability and uniform permeability."From the numerical results, an excellent agreement has been observed for the present results, as well as comparison is made between the present and the earlier works for a particular case of the problem.

scholarly journals Effect of Suspended Particles on Thermosolutal Convection of Rivlin-Ericksen Fluid in Porous Medium with Variable Gravity

2018 ◽  
Vol 23 (3) ◽  
pp. 813-820 ◽  
Author(s):  
A.K. Aggarwal ◽  
D. Dixit
Keyword(s):  
Porous Medium ◽  
Suspended Particles ◽  
Thermosolutal Convection ◽  
Stationary Convection ◽  
Medium Permeability ◽  
Stabilizing Effect ◽  
Variable Gravity ◽  
Solute Gradient

Abstract The thermosolutal stability of a layer of the Rivlin-Ericksen fluid in a porous medium is considered under varying gravity conditions. It is found that for stationary convection, medium permeability and suspended particles have a destabilizing/stabilizing effect when gravity increases/decreases. The stable solute gradient has a stabilizing effect on the system.

scholarly journals On thermosolutal convection in presence of compressible fluid with fine dust

2014 ◽  
Vol 19 (1) ◽  
pp. 133-143
Author(s):  
M. Singh ◽  
R.K. Gupta
Keyword(s):  
Viscous Fluid ◽  
Compressible Fluid ◽  
Suspended Particles ◽  
Thermosolutal Convection ◽  
Fine Dust ◽  
Stationary Convection ◽  
Onset Of Convection ◽  
Stabilizing Effect ◽  
Dust Effect ◽  
Solute Gradient

Abstract A layer of a Rivlin-Ericksen elastico-viscous fluid heated and soluted from below in the presence of compressibility and suspended particles (fine dust) effect is considered. For stationary convection, the Rivlin- Ericksen, elastico-viscous fluid behaves like a Newtonian fluid. The oscillatory modes are introduced due to the presence of a stable solute gradient, suspended particles destabilize the system whereas the stable solute gradient has a stabilizing effect on the system and the effect of compressibility is to postpone the onset of thermosolutal convection. The stable solute gradient and compressibility postpone the onset of convection, whereas the suspended particles hasten the onset of convection. The stable solute gradient introduces oscillatory modes in the systems which were non-existent in its absence

Thermal Instability in Rivlin-Ericksen Elastico-Viscous Fluids in Hydromagnetics

1997 ◽  
Vol 52 (4) ◽  
pp. 369-371 ◽  
Author(s):  
R. C. Sharma ◽  
P. Kumar
Keyword(s):  
Magnetic Field ◽  
Viscous Fluid ◽  
Newtonian Fluid ◽  
Thermal Instability ◽  
Viscous Fluids ◽  
Sufficient Condition ◽  
Vertical Magnetic Field ◽  
Stationary Convection ◽  
Stabilizing Effect ◽  
The Magnetic Field

Abstract The thermal instability of a layer of Rivlin-Ericksen elastico-viscous fluid acted on by a uniform vertical magnetic field is considered. For stationary convection, a Rivlin-Ericksen elastico-viscous fluid behaves like a Newtonian fluid. The magnetic field has a stabilizing effect. It is found that the presence of a magnetic field introduces oscillatory modes which were non-existent in its absence. The sufficient condition for the non-existence of overstability is also obtained.

scholarly journals Compressible Analysis of Bénard Convection of Magneto Rotatory Couple-Stress Fluid

2018 ◽  
Vol 23 (1) ◽  
pp. 91-105
Author(s):  
C.B. Mehta ◽  
M. Singh
Keyword(s):  
Magnetic Field ◽  
Couple Stress ◽  
Thermal Instability ◽  
Sufficient Conditions ◽  
Couple Stress Fluid ◽  
Stationary Convection ◽  
Onset Of Convection ◽  
Linearized Stability ◽  
Exchange Of Stability ◽  
The Magnetic Field

AbstractThermal Instability (Benard’s Convection) in the presence of uniform rotation and uniform magnetic field (separately) is studied. Using the linearized stability theory and normal mode analyses the dispersion relation is obtained in each case. In the case of rotatory Benard’s stationary convection compressibility and rotation postpone the onset of convection whereas the couple-stress have duel character onset of convection depending on rotation parameter. While in the absence of rotation couple-stress always postpones the onset of convection. On the other hand, magnetic field on thermal instability problem on couple-stress fluid for stationary convection couple-stress parameter and magnetic field postpones the onset of convection. The effect of compressibility also postpones the onset of convection in both cases as rotation and magnetic field. Graphs have been plotted by giving numerical values to the parameters to depict the stationary characteristics. Further, the magnetic field and rotation are found to introduce oscillatory modes which were non-existent in their absence and then the principle of exchange of stability is valid. The sufficient conditions for non-existence of overstability are also obtained.

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