STATIONARY CONVECTION IN THE ELECTROHYDRODYNAMIC THERMAL INSTABILITY OF JEFFREY NANOFLUID LAYER SATURATING A POROUS MEDIUM: FREE-FREE, RIGID-FREE, AND RIGID-RIGID BOUNDARY CONDITIONS
Poonam Kumari Gautam, Gian C. Rana, Hemlata Saxena
Abstract
The onset of stationary convection in electrohydrodynamic thermal instability of Jeffrey nanofluid layer saturating a porous medium for free-free, rigid-free, and rigid-rigid boundaries is studied. Darcy-Jeffrey fluid model is used to describe rheological behavior of nanofluid. The conservation of momentum equations are modified due to the presence of Jeffrey parameter and under the influence of an applied alternating current (AC) electric field by the inclusion of dielectrophoretic force and Coulomb force. By applying linear stability analysis based upon perturbation theory and one-term Galerkin method, we derive the expression for thermal Rayleigh number for free-free, rigid-free, and rigid-rigid boundaries on the onset of stationary convection. The effects of Jeffrey parameter, AC electric Rayleigh number, Lewis number, modified diffusivity ratio, nanoparticle Rayleigh number, and medium porosity have been discussed for the case of stationary convection.