Periodic electroosmotic flow of nanofluids with slip-dependent high zeta potential

Abstract

The time periodic electroosmotic flow of nanofluids is investigated analytically in a hydrophobic microchannel. In this study, we consider the interdependence relationship between the wall electrical potential and slip. According to the non-linear slip-dependent zeta potential, we obtain an analytical solution of electrical potential for arbitrary value of wall electrical potential. Subsequently, we give the analytical integration expression of time periodic electroosmotic velocity of nanofluids. Based on the obtained electrical potential distribution, the oscillating flow velocity and rate are calculated numerically. The flow characteristics are determined by the oscillating frequency of electrical field, the volume fraction of nanoparticles and wall electrical potential. The noteworthy results are that, the oscillating electrical field can result in the oscillation of nanofluids. However, such oscillation is strongly dependent on the electrical field frequency and the flow characteristics are significantly different for various frequencies. Moreover, when the nanoparticles are introduced into the time periodic electroosmotic flow, the oscillation can be restrained. This may be helpful to understand the electrohydrodynamic instability of nanofluids.