The Onset of Electrothermoconvection in a Dielectric Viscoelastic Navier-Stokes-Voigt Fluid in Sparsely Distributed Porous Medium

In this present paper, the effect of a vertical AC electric field on the dielectric viscoelastic liquid layer (Navier-Stokes- Voigt model) saturating a porous medium is investigated using the Darcy-Brinkman model when heated from above or below. The eigenvalue problem is solved exactly for free-free boundaries, and the Galerkin technique is used for rigid- rigid boundaries. The impact of the electric field on the fluid system for stationary convection is analyzed numerically and predicted graphically. Further, it has been shown that an increase in the inverse Darcy number Da–1 and the ratio of viscosities Λ enforce the stability of the Navier-Stokes-Voigt viscoelastic dielectric fluid layer. It has also been observed that the thermal Rayleigh number and the onset of stationary convection is independent of Navier-Stokes- Voigt parameter λ. It is also predicted that the system is more stable when heated from above than below.