scholarly journals The effect of rotation on the onset of electrohydrodynamic instability of an elastico-viscous dielectric fluid layer

2016 ◽  
Vol 64 (1) ◽  
pp. 143-149 ◽  
Author(s):  
G.C. Rana ◽  
R. Chand ◽  
V. Sharma
Keyword(s):  
Viscous Fluid ◽  
Electric Field ◽  
Fluid Layer ◽  
Fluid Model ◽  
Rheological Behaviour ◽  
Necessary Condition ◽  
Dielectric Fluid ◽  
Free Boundaries ◽  
Oscillatory Convection ◽  
Ac Electric Field

Abstract In this paper the combined effect of uniform rotation and AC electric field on the onset of instability in a horizontal layer of an elastico-viscous fluid stimulated by the dielectrophoretic force due to the variation of dielectric constant with temperature is studied. Walters’ (model B’) fluid model is used to describe rheological behaviour of an elastico-viscous fluid. The onset criterions for stationary and oscillatory convection are derived for the case of free-free boundaries. It is observed that Walters’ (model B’) fluid behaves like an ordinary Newtonian fluid and rotation has stabilizing influence whereas AC electric field has destabilizing influence on the stability of the system. The necessary condition for the occurrence of oscillatory convection is also obtained. The present results are in good agreement with the earlier published results.

scholarly journals Effect of Horizontal AC Electric Field on the Stability of Natural Convection in a Vertical Dielectric Fluid Layer

2016 ◽  
Vol 9 (6) ◽  
pp. 3073-3086 ◽  
Author(s):  
B. M. Shankar ◽  
J. Kumar ◽  
I. S. Shivakumara ◽  
S. B. Naveen Kumar ◽  
◽  
...  
Keyword(s):  
Natural Convection ◽  
Electric Field ◽  
Fluid Layer ◽  
Dielectric Fluid ◽  
Ac Electric Field ◽  
The Stability

Dufour and Soret Effects on the Thermosolutal Instability of Rivlin– Ericksen Elastico–Viscous Fluid in Porous Medium

2012 ◽  
Vol 67 (12) ◽  
pp. 685-691 ◽  
Author(s):  
Ramesh Chand ◽  
Gian Chand Rana
Keyword(s):  
Porous Medium ◽  
Viscous Fluid ◽  
Fluid Layer ◽  
Normal Mode Analysis ◽  
Lewis Number ◽  
Horizontal Layer ◽  
Mode Analysis ◽  
Free Boundaries ◽  
Oscillatory Convection ◽  
The Stability

Dufour and Soret effects on the convection in a horizontal layer of Rivlin-Ericksen elastico- viscous fluid in porous medium are considered. For the porous medium, the Darcy model is used. A linear stability analysis based upon normal mode analysis is employed to find a solution of the fluid layer confined between two free boundaries. The onset criterion for stationary and oscillatory convection has been derived analytically, and graphs have been plotted, giving various numerical values to various parameters, to depict the stability characteristics. The effects of the Dufour parameter, Soret parameter, solutal Rayleigh number, and Lewis number on stationary convection have been investigated.

The Stability of Natural Convection in an Inclined Fluid Layer in the Presence of AC Electric Field

1996 ◽  
Vol 65 (8) ◽  
pp. 2479-2484 ◽  
Author(s):  
Mohamed A. K. El Adawi ◽  
El Sayed F. El Shehawey ◽  
Safaa A. Shalaby ◽  
Mohamed I. A. Othman
Keyword(s):  
Natural Convection ◽  
Electric Field ◽  
Fluid Layer ◽  
Ac Electric Field ◽  
Inclined Fluid Layer ◽  
The Stability

Effect of Gravity Modulation on Electrothermal Convection in a Dielectric Fluid Saturated Anisotropic Porous Layer

2013 ◽  
Vol 136 (3) ◽  
Author(s):  
Mahantesh S. Swamy ◽  
I. S. Shivakumara ◽  
N. B. Naduvinamani
Keyword(s):  
Heat Transfer ◽  
Electric Field ◽  
Porous Layer ◽  
Initial Conditions ◽  
Low Frequency ◽  
Dielectric Fluid ◽  
Gravity Modulation ◽  
Regular Perturbation ◽  
Stability Parameters ◽  
Ac Electric Field

This paper deals with linear and nonlinear stability analyses of thermal convection in a dielectric fluid saturated anisotropic Brinkman porous layer subject to the combined effect of AC electric field and time-periodic gravity modulation (GM). In the realm of linear theory, the critical stability parameters are computed by regular perturbation method. The local nonlinear theory based on truncated Fourier series method gives the information of convection amplitudes and heat transfer. Principle of exchange of stabilities is found to be valid and subcritical instability is ruled out. Based on the governing linear autonomous system several qualitative results on stability are discussed. The sensitive dependence of the solution of Lorenz system of electrothermal convection to the choice of initial conditions points to the possibility of chaos. Low frequency g-jitter is found to have significant stabilizing influence which is in turn diminished by an imposed AC electric field. The role of other governing parameters on the stability threshold and on transient heat transfer is determined.

scholarly journals On the Onset of Thermal Convection in a Layer of Oldroydian Visco-Elastic Fluid Saturated by Brinkman–Darcy Porous Medium

2015 ◽  
Vol 37 (4) ◽  
pp. 3-10 ◽  
Author(s):  
Ramesh Chand
Keyword(s):  
Porous Medium ◽  
Thermal Instability ◽  
Fluid Layer ◽  
Darcy Number ◽  
Horizontal Layer ◽  
Relaxation Parameter ◽  
Free Boundaries ◽  
Oscillatory Convection ◽  
Elastic Fluid ◽  
Mode Technique

AbstractThermal instability in a horizontal layer of Oldroydian visco-elastic fluid in a porous medium is investigated. For porous medium the Brinkman–Darcy model is considered. A linear stability analysis based upon perturbation method and normal mode technique is used to find solution of the fluid layer confined between two free-free boundaries. The onset criterion for stationary and oscillatory convection is derived analytically. The influence of the Brinkman–Darcy, Prandtl–Darcy number, stress relaxation parameter on the stationary and oscillatory convection is studied both analytically and graphically. The sufficient condition for the validity of PES has also been derived.

Thermal Instability of Rivlin–Ericksen Elastico-Viscous Nanofluid Saturated by a Porous Medium

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
Ramesh Chand ◽  
G. C. Rana
Keyword(s):  
Porous Medium ◽  
Thermal Instability ◽  
Fluid Layer ◽  
Normal Mode Analysis ◽  
Sufficient Conditions ◽  
Lewis Number ◽  
Mode Analysis ◽  
Free Boundaries ◽  
Oscillatory Convection ◽  
The Stability

Thermal instability in a horizontal layer of Rivlin–Ericksen elastico-viscous nanofluid in a porous medium is considered. A linear stability analysis based upon normal mode analysis is used to find a solution of the fluid layer confined between two free boundaries. The onset criterion for stationary and oscillatory convection is derived analytically and graphs have been plotted by giving numerical values to various parameters to depict the stability characteristics. The effects of the concentration Rayleigh number, Vadasz number, capacity ratio, Lewis number, and kinematics viscoelasticity parameter on the stability of the system are investigated. Regimes of oscillatory and nonoscillatory convection for various parameters are derived and discussed in detail. The sufficient conditions for the nonexistence of oscillatory convection have also been obtained.

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