Electrohydrodynamic stability of couple stress fluid flow in a channel occupied by a porous medium

Abstract

The linear stability of electrohydrodynamic poorly conducting couple stress viscous parallel fluid flow through a porous channel is studied in the presence of a nonuniform transverse electric field using an energy method. Supplemented with a single term Galerkin expansion. The sufficient condition for stability is obtained using the nature of the growth rate as well as sufficiently small values of the Reynolds number, Re. From this condition we show that strengthening or weakening of the stability criterion is dictated by the values of the strength of the electric field, the coefficient of couple stress fluid, and the porous parameter. In particular, it is shown that the interaction of the electric field with couple stress is more effective in stabilizing the poorly conducting couple stress fluid compared with that in an ordinary Newtonian viscous fluid.