Two-layer electro-osmotic flow and heat transfer in a hydrophobic micro-channel with fluid–solid interfacial slip and zeta potential difference

Abstract

Of concern in this paper is an investigation of two-layer fluid flow and heat transfer in a hydrophobic micro-channel by considering the combined influence of pressure gradient and electro-osmotic forces. The wall slip effects due to hydrophobic interactions at the fluid–solid interface has been taken into account. The governing equations consisting with the linearized Poisson–Boltzmann equation, the Cauchy momentum equation and thermal energy equation are solved analytically within the framework of the Debye–Hückel approximation. The effects of different dimensionless parameters and the interface zeta potential difference on the axial velocity as well as the temperature distribution are presented graphically. The slip velocity on the fluid flow and the Joule heating effects on the temperature are furthermore investigated. The study reveals that the temperature enhancement is strongly depends on the Joule heating parameter as well as the Brinkman number. The zeta potential difference plays an important role in controlling fluid velocity in the micro-channel. For validation of our results, a comparison has been made with the results of those available in the scientific literature and shows excellent agreement.