scholarly journals Study of double-diffusive convection in a rotating couple-stress ferromagnetic fluid in the presence of varying gravitational field and horizontal magnetic field saturating in a porous medium

2021 ◽  
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Gravitational Field ◽  
Couple Stress ◽  
Double Diffusive Convection ◽  
Horizontal Magnetic Field ◽  
Diffusive Convection ◽  
Ferromagnetic Fluid ◽  
Double Diffusive

scholarly journals Double-Diffusive Convection of Synovial (Couple-Stress) Fluid in the Presence of Hall Current Through a Porous Medium

2018 ◽  
Vol 23 (4) ◽  
pp. 963-976
Author(s):  
M. Singh
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Synovial Fluid ◽  
Couple Stress ◽  
Hall Current ◽  
Couple Stress Fluid ◽  
Double Diffusive Convection ◽  
Onset Of Convection ◽  
Diffusive Convection ◽  
Double Diffusive

Abstract An investigation made on the effect of Hall currents on double-diffusive convection of a compressible synovial (couple-stress) fluid in the presence of a horizontal magnetic field through a porous layer is considered. The analysis is carried out within the framework of linear stability theory and normal mode technique. A dispersion relation governing the effects of viscoelasticity, compressibility, magnetic field and porous layer is derived. For the stationary convection, a synovial fluid behaves like an ordinary Newtonian fluid due to the vanishing of the viscoelastic parameter. The stable-solute gradient, compressibility, and magnetic field have postponed the onset of convection, whereas Hall currents and medium permeability have not postponed the onset of convection, moreover, a synovial fluid has a dual character in the presence of Hall currents, whereas in the absence of Hall current in synovial fluid have postponed the onset of convection, which is in contrast in case of thermal convection couple-stress fluid with same effects. These analytic results are confirmed numerically and the effects of various parameters are depicted graphically. It has been observed that oscillatory modes are introduced due to the presence of viscoelasticity, magnetic field, porous medium and Hall currents which were non- existent in their absence. The sufficient conditions for the non-existence of overstability are also obtained.

scholarly journals Thermal Instability of a Couple-Stress Ferromagnetic Fluid in the Presence of Variable Gravity Field and Horizontal Magnetic Field with Hall Currents Saturating in a Porous Medium

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Sudhir Kumar Pundir ◽  
◽  
Pulkit Kumar Nadian ◽  
Rimple Pundir ◽  
◽  
...  
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Gravity Field ◽  
Couple Stress ◽  
Thermal Instability ◽  
Horizontal Magnetic Field ◽  
Variable Gravity ◽  
Ferromagnetic Fluid

https://jusst.org/thermal-instability-of-a-couple-stress-ferromagnetic-fluid-in-the-presence-of-variable-gravity-field-and-horizontal-magnetic-field-with-hall-currents-saturating-in-a-porous-medium/

scholarly journals On the Onset of Double-diffusive Convection in a Couple Stress Nanofluid in a Porous Medium

2018 ◽  
Vol 62 (3) ◽  
pp. 233-240
Author(s):  
Gian C. Rana ◽  
Ramesh Chand
Keyword(s):  
Porous Medium ◽  
Rayleigh Number ◽  
Couple Stress ◽  
Lewis Number ◽  
Double Diffusive Convection ◽  
Stationary Convection ◽  
Stress Parameter ◽  
Diffusive Convection ◽  
Double Diffusive ◽  
Solutal Rayleigh Number

Double-diffusive convection in a horizontal layer of nanofluid in a porous medium is studied. The couple-stress fluid model is considered to describe the rheological behavior of the nanofluid and for porous medium Darcy model is employed. The model applied for couple stress nanofluid incorporates the effect of Brownian motion and thermophoresis. We have assumed that the nanoparticle concentration flux is zero on the boundaries which neutralizes the possibility of oscillatory convection and only stationary convection occurs. The dispersion relation describing the effect of various parameters is derived by applying perturbation theory, normal mode analysis method and linear stability theory. The impact of various physical parameters, like the couple stress parameter, medium porosity, solutal Rayleigh Number, thermo-nanofluid Lewis number, thermo-solutal Lewis number, Soret parameter and Dufour parameter have been examined on the stationary convection. It is observed that the couple stress parameter, thermo-nanofluid Lewis number, thermo-solutal Lewis number, Soret parameter and Dufour parameter have stabilizing effects on the stationary convection whereas the solutal Rayleigh number and Dufour parameter have very small effect on the system.

Sign in / Sign up

Export Citation Format

Share Document