NONLINEAR EHD INSTABILITY OF A CYLINDRICAL INTERFACE BETWEEN TWO WALTERS B' FLUIDS IN POROUS MEDIA
Galal M. Moatimid, Marwa H. Zekry, N. S. Gad
Abstract
The current paper examines the nonlinear EHD instability of a cylindrical interface between two viscoelastic fluids of Walters' B type in saturated porous media. A uniform axial electric field is acted upon with the axis of the cylinder. The procedure of the nonlinear stability yields a nonlinear characteristic equation of the interface deflection. Consequently, the stability criteria are analytically discussed and numerically confirmed. The multiple time scale technique together with the aid Taylor expansion produce a Ginzburg-Landau equation. This equation judges the nonlinear stability criteria. In addition, the concept of the expanded frequency along with the homotopy perturbation method are adopted to achieve an analytic periodic approximate distribution of the surface evaluation. Several special cases are reported by using appropriate data choices. Throughout the stability investigation, the electric field intensity is plotted versus the wave number. The influences of various parameters on the stability picture are addressed. The nonlinear stability approach divides the phase plane into several parts of stability/instability regions.