NUMERICAL SIMULATION ON INFLUENCE FACTORS OF
ELECTROOSMOTIC FLOW IN RECTANGULAR MICROCHANNEL

ZHANG Peng¹ ZUO Chuncheng¹ ZHOU Deyi²

(1. College of Mechanical Science and Engineering, Jilin University, Changchun 130022;

2. College of Biology and Agriculture Engineering, Jilin University, Changchun 130022 )

Abstract: Aiming at the design parameter optimization problem of the electroosmotic pumping, the mathematic model of electroosmotic flow is made. The coupling equations governing the electric double layer (EDL) field and the velocity field in the cross-section of rectangular microchannels are numerically solved by employing a finite control volume scheme. The dependence of the potential, velocity and volumetric flowrate on the aspect ratio, hydraulic diameter, liquid properties and the applied electrical field is analyzed. And the fitting polynomials of the relationships between the volumetric flow, average velocity and influence factors are presented. The numerical simulation results show that the volumetric flowrate decreases as the aspect ratio increases. When the aspect ratio approaches 1, the volumetric flowrate is minimum. The volumetric flowrate in-creased with the square of hydraulic diameter. The average velocity is dependent on the ionic concentration and the applied electrical field strength. However, the aspect ratio and hydraulic diameter have little impact on the average velocity.

Key words: Electroosmotic flow Influence factors Finite control volume scheme Rectangular microchannel Numerical simulation

CLC No: O351.2 TQ028.7

国家自然科学基金(10572053)、高等学校博士学科点专项科研基金 (20040183057)和浙江大学流体传动及控制国家重点实验室开放基金 (GZKF-2003005)资助项目. Received 20060415, received in revised form 20061122收到修 改稿