Heat transfer of nanofluid with electroviscous effect in MHD-based microannulus

Abstract

Thermally fully developed electrokinetic flow of nanofluid is investigated in a microannulus under the effect of electromagnetic field. The electroviscous effect on heat transfer of nanofluid is analyzed theoretically. Based on the Debye–Huckel linearization approximation, the analytical expressions of electrical potential, flow velocity and streaming potential are derived. Then, the temperature distribution of nanofluid is obtained by the finite difference numerical method. The influences of nanoparticle volume fraction, magnetic field and radius ratio on streaming potential and temperature are discussed in detail. It is revealed that the streaming potential can be enhanced with the increase in magnetic field strength. For various nanoparticle volume fractions, a threshold value of magnetic field strength can be obtained. Besides, local fluid temperature can effectively be enhanced with the increase in nanoparticle volume fraction. Finally, the effect of convective heat transfer can be regulated by the nanoparticle volume fraction, magnetic field strength and microannulus scale. The present work can provide a theoretical contribution to the flow and heat transfer of nanofluid in microannulus.