Conditional stability for thermal convection in a rotating couple-stress fluid saturating a porous media with temperature- and pressure-dependent viscosity using a thermal non-equilibrium model

2014 ◽  
Vol 39 (2) ◽  
Author(s):  
Sunil ◽  
Shalu Choudhary ◽  
Amit Mahajan
Keyword(s):  
Equilibrium Model ◽  
Couple Stress ◽  
Linear Instability ◽  
Couple Stress Fluid ◽  
Conditional Stability ◽  
Onset Of Convection ◽  
Pressure Dependent Viscosity ◽  
Temperature And Pressure ◽  
Dependent Viscosity ◽  
Non Equilibrium

Abstract.A nonlinear stability threshold for convection in a rotating couple-stress fluid saturating a porous medium with temperature- and pressure-dependent viscosity using a thermal non-equilibrium model is found to be exactly the same as the linear instability boundary. This optimal result is important because it shows that linear theory has completely captured the physics of the onset of convection. The effects of couple-stress fluid parameter

scholarly journals GLOBAL STABILITY FOR THERMAL CONVECTION IN A COUPLE-STRESS FLUID WITH TEMPERATURE AND PRESSURE DEPENDENT VISCOSITY

2013 ◽  
Vol 35 (3) ◽  
pp. 85-102 ◽  
Author(s):  
◽  
Shalu Choudhary ◽  
P. K. Bharti
Keyword(s):  
Couple Stress ◽  
Linear Instability ◽  
Optimal Result ◽  
Onset Of Convection ◽  
Stability Threshold ◽  
Instability Theory ◽  
Pressure Dependent Viscosity ◽  
Temperature And Pressure ◽  
Dependent Viscosity ◽  
Instability Boundary

Abstract We show that the global nonlinear stability threshold for convection in a couple-stress fluid with temperature and pressure dependent viscosity is exactly the same as the linear instability boundary. This optimal result is important because it shows that linearized instability theory has captured completely the physics of the onset of convection. It has also been found that the couplestress fluid is more stable than the ordinary viscous fluid and then the effect of couple-stress parameter (F) and variable dependent viscosity (Γ) on the onset of convection is also analyzed.

scholarly journals Global Stability For Double-Diffusive Convection In A Couple-Stress Fluid Saturating A Porous Medium

2019 ◽  
Vol 41 (1) ◽  
pp. 13-20
Author(s):  
Shalu Choudhary ◽  
Keyword(s):  
Porous Medium ◽  
Couple Stress ◽  
Linear Instability ◽  
Couple Stress Fluid ◽  
Brinkman Number ◽  
Onset Of Convection ◽  
Instability Theory ◽  
Diffusive Convection ◽  
Solute Gradient ◽  
Double Diffusive

Abstract We show that the global non-linear stability threshold for convection in a double-diffusive couple-stress fluid saturating a porous medium is exactly the same as the linear instability boundary. The optimal result is important because it shows that linearized instability theory has captured completely the physics of the onset of convection. It is also found that couple-stress fluid saturating a porous medium is thermally more stable than the ordinary viscous fluid, and the effects of couple-stress parameter (F ) , solute gradient ( S f ) and Brinkman number ( D a ) on the onset of convection is also analyzed.

Global nonlinear stability in porous convection with a thermal non-equilibrium model

2005 ◽  
Vol 462 (2066) ◽  
pp. 409-418 ◽  
Author(s):  
B Straughan
Keyword(s):  
Nonlinear Stability ◽  
Equilibrium Model ◽  
Linear Instability ◽  
Darcy Law ◽  
Optimal Result ◽  
Onset Of Convection ◽  
Stability Threshold ◽  
Instability Theory ◽  
Porous Medium Equations ◽  
Non Equilibrium

We show that the global nonlinear stability threshold for convection with a thermal non-equilibrium model is exactly the same as the linear instability boundary. This result is shown to hold for the porous medium equations of Darcy, Forchheimer or Brinkman. This optimal result is important because it shows that linearized instability theory has captured completely the physics of the onset of convection. The equivalence of the linear instability and nonlinear stability boundaries is also demonstrated for thermal convection in a non-equilibrium model with the Darcy law, when the layer rotates with a constant angular velocity about an axis in the same direction as gravity.

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