Flow and heat transfer of nanofluid through a horizontal microchannel with magnetic field and interfacial electrokinetic effects

Abstract

Flow and heat transfer of a nanofluid through a horizontal microchannel in the presence of the magnetic field effects and electric double layer (EDL) is investigated theoretically. For a microchannel with a large aspect ratio, the flow problem is treated as a two-dimensional nonlinear system. The body force generated by the EDL and magnetic field is considered in momentum equation. In order to study the mechanism of nanofluid heat transfer, the nanoparticles distribution and the heat transfer process of nanofluid flow are represented by the Buongiorno’s nanofluid model with the passively controlled nanoparticles distribution at the boundary, which has not been considered in previous microchannel studies. Compared to the so-called active control of nanoparticle volume fraction at the boundary, the current approach makes the model physically more reliable by taking into account of the effect due to varying temperature. The analytical approximations obtained by the homotopy analysis method reveals that both the magnetic field effects and the EDL play significant roles on altering the flow and heat transfer in microchannels. It is also found that the heat enhancement is significantly depend on the Brinkman number and the temperature applied to the wall.