Electrothermosolutal convection in nanofluid

Abstract

This article employs linear stability theory to investigate the thermosolutal instability phenomenon within a horizontal layer of nanofluid subjected to a vertical alternating current (AC) electric field while being heated from below. The model integrates the impacts of Brownian diffusion, thermophoresis, and electrophoresis into the nanofluid dynamics. Free-free boundary conditions are assumed at the upper and lower boundaries of the fluid layer. Employing the normal mode technique, the set of coupled differential equations is solved analytically for stress-free boundaries. The computed numerical values of the stationary thermal Rayleigh number are illustrated graphically. The conditions for nonexistence of overstability are also derived. The study focuses on stationary convection, examining the analytical and graphical implications of modified diffusivity ratio, AC electric Rayleigh number, solutal Lewis number, nanofluid Lewis number, solutal Rayleigh number, and nanoparticle Rayleigh number on the system dynamics. The analysis demonstrates that the nanofluid Lewis number and modified diffusivity ratio produce a stabilizing effect on the initiation of convection, notably delaying its onset. AC electric field and solutal Rayleigh number exhibit a destabilizing influence, notably accelerating the onset of convection.

Keywords:

• Electric field
• nanofluid
• thermosolutal

Disclosure statement

No potential conflict of interest was reported by the authors.