Numerical simulation of a backward-facing step flow in a microchannel with external electric field

Qing-He Yao,Qing-Yong Zhu

doi:10.1177/1687814014568540

Abstract

A backward-facing step flow in the microchannel with external electric field was investigated numerically by a high-order accuracy upwind compact difference scheme in this work. The Poisson–Boltzmann and Navier–Stokes equations were computed by the high-order scheme, and the results confirmed the ability of the new solver in simulation of micro-scale electric double layer effects. The flow fields were displayed for different Reynolds numbers; the positions of the vortex saddle point of model with external electric field and model without external electric field were compared. The average velocity increases linearly with the electric field intensity; however, the Joule heating effects cannot be neglected when the electric field intensity increases to a certain level.

Highlights

With the development of micro- and nano-technology in recent years, the study on electric double layer (EDL) is changing from theoretical analysis to applied research
The electrolyte solution under an applied electric field is driven by the Coulomb force, and the internal liquid molecules start to move; the EDL effect appears on the solid–liquid interface.[1]
Based on a high-accuracy upwind compact difference method, the Navier–Stokes equations of vortex-stream form and the Poisson–Boltzmann equation were solved in this work

Summary

Introduction

With the development of micro- and nano-technology in recent years, the study on electric double layer (EDL) is changing from theoretical analysis to applied research. By using a high-order accuracy upwind compact difference scheme, the current research focuses on the simulation of the EDL in a microchannel with a backward-facing step. When an electric field is applied at the top and bottom of the microchannel, electrostatic charges in the EDL are driven by the electric force and start to move.

Results

Conclusion