Heat transfer of nanofluids in microtubes under the effects of streaming potential

In the current study, the heat transfer characteristics of thermally developed electrokinetic flow of the nanofluid (water-Al2O3) through a microtube are investigated. The flow is actuated by the combined effects of pressure-driven and electroosmotic transport induced by streaming potential. A uniform flux at the surfaces of the microtube is exerted and the influences of viscous dissipation as well as Joule heating are taken into account. Based on the Debye-Huckel linearization approximation, the relevant velocity and temperature distributions are derived. Furthermore, Nusselt number variations are evaluated. Physical feathers of pertinent parameters such as electrokinetic width K, volume friction phi, slip lengthen gamma, Brinkman number Br and Joule parameter S are presented graphically and discussed in detail. It is revealed that nanoparticles have significant influences on the electrokinetics and heat transfer characteristics of nanofluids under the streaming potential. (C) 2016 Elsevier Ltd. All rights reserved.