Vol.21, No.1, 2021, pp. 108–117
UDC:

In this paper we study electrothermal convection in a horizontal layer of Maxwellian dielectric nanofluid saturating a porous medium. Darcy-Maxwellian fluid model is used to describe rheological behaviour of nanofluid. The used model for nanofluid incorporates the effects of thermophoresis and Brownian diffusion. The Navier-Stokes equations of motion are modified due to the presence of applied 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 cases of stationary convection and oscillatory motion. Effects of Vadasz number, AC electric Rayleigh number, Lewis number, modified diffusivity ratio, nanoparticle Rayleigh number and medium porosity have been discussed for the case of stationary and oscillatory convection.

Keywords: nanofluid, electrothermal-convection, Rayleigh number, Maxwell model, porous medium