The electrokinetic energy conversion analysis of Newtonian fluids with pressure-dependent viscosity in rectangular nanotube

Abstract

In this work, a theoretical analysis for the streaming potential and the electro-kinetic energy conversion (EKEC) efficiency of Newtonian fluids with pressure-dependent viscosity in rectangular nanotube was developed. Accordingly, the dimensionless velocity, dimensionless streaming potential, dimensionless pressure and the electrokinetic energy conversion (EKEC) efficiency are obtained by using the perturbation method expanded in terms of the pressure-viscosity coefficient based on a linear dependent relationship between viscosity and pressure. The results indicate that with pressure-viscosity coefficient, the pressure required to drive the flow increases sharply. Also as pressure-viscosity coefficient increases, the streaming potential and EKEC efficiency decreases gradually, contrary to velocity. It is worth noting that within the given parameter range, the maximum efficiency obtained by present analysis is about 0.19% when pressure viscosity coefficients is 0.001. Moreover, appropriately adjusting ratio of channel width to height and the geometrical aspect ratio of the nanotube can improve effectively the streaming potential and the EKEC efficiency.