Numerical Simulation on Electroosmotic Flow in a Rectangular Microchannel

Abstract

Computer simulations of electroosmotic flow through rectangular microchannels have been completed in this paper. A 2D Poisson-Boltzmann equation and a 2D Navier-Stokes equation governing the electric double layer (EDL) field and velocity field in the cross section of rectangular microchannels are numerically solved by employing a finite control volume scheme without the use of Debye-Huckel approximation. The numerical solutions show the influences of the channel cross-section geometry (i.e. the aspect ratio), channel size, the ionic concentration and the applied electrical field strength on the volumetric flowrate and the average velocity. And the numerical simulation results show significant influences of the channel cross-section geometry on the volumetric flowrate. Also, the numerical simulation results show that the volumetric flowrate increased with the square of hydraulic diameter. However, increases in hydraulic diameter have little impact on the average velocity. The objective of this paper is to provide the basis for electroosmotic pumping