PERIODICAL PRESSURE-DRIVEN FLOWS IN MICROCHANNEL WITH WALL SLIP VELOCITY AND ELECTRO-VISCOUS EFFECTS

作     者：WANG Lei WU Jian-kang WANG Lei,WU Jian-kang Department of Mechanics,Huazhong University of Science and Technology,National Laboratory for Optoelectronics,Wuhan 430074,China

作者机构：Department of Mechanics Huazhong University of Science and Technology National Laboratory forOptoelectronics Wuhan 430074 China 

出 版 物：《Journal of Hydrodynamics》 (水动力学研究与进展B辑（英文版）)

年 卷 期：2010年第22卷第6期

页      面：829-837页

核心收录：

学科分类：081704[工学-应用化学] 08[工学] 0817[工学-化学工程与技术] 081701[工学-化学工程] 082701[工学-核能科学与工程] 0827[工学-核科学与技术] 

基　　金：Project supported by the National Natural Science Foundation of China (Grant No. 50805059) 

主　　题：electrokinetic flow frequency Reynolds number wall slip electro-viscous effects Flow-Induced Electric Field (FIEF) 

摘      要：In a microfluidic system, the flow slip velocity on a solid wall can be the same order of magnitude as the average velocity in the microchannel. The flow-electricity interaction in a complex microfluidic system subjected to a joint action of wall slip and electro-viscosity is an important topic. An analytical solution for the periodical pressure-driven flow in a two-dimensional uniform microchannel, with consideration of wall slip and electro-viscous effect is obtained based on the Poisson-Boltzmann equation for the Electric Double Layer （EDL） and the Navier-Stokes equations for the liquid flow. The analytic solutions agree well with the numerical solutions. The analytical results indicate that the periodical flow velocity and the Flow-Induced Electric Field （FIEF） strongly depend on the frequency Reynolds number （Re = （wh2/v ）, that is a function of the frequency, the channel size and the kinetic viscosity of fluids. For Re 〈 1, the flow velocity and the FIEF behave similarly to those in a steady flow, whereas they decrease rapidly with Re as Re 〉 1. In addition, the electro-viscous effect greatly influences the periodical flow velocity and the FIEF, particularly, when the electrokinetic radius kH is small. Furthermore, the wall slip velocity amplifies the FIEF and enhances the electro-viscous effect on the flow.