摘要
由于固-液界面双电层的作用,矩形微流道中的压力驱动流存在电动效应。矩形微流道截面上双电层场和速度场的控制方程分别是二维Poisson-Boltzmann方程和修正Navier-Stokes方程。应用有限控制容积法对控制方程进行了数值求解,并计算了压力梯度与雷诺数之间的关系,模型预测值与试验值之差在5%之内。相同尺寸的微流道中,考虑电动效应的模型预测液体摩擦系数的值大于宏观流体理论中液体摩擦系数的值,且电解质溶液浓度越低,摩擦系数偏离宏观流体理论值越大。
The presence of the Electrical Double Layer （EDL） near a solid-liquid interface results in the electrokinetic effect on pressure-driven liquid flow through microchannels. The equations governing the EDL field and the velocity field in the cross-section of rectangular microchannels are the two-dimensional Poisson-Boltzmann equation and the modified Navier-Stokes equation, respectively. In this paper,the equations are numerically solved employing a finite control volume scheme. The relationship between the pressure gradients and the Reynolds numbers is computed, and the differences between the predicted and the experimental Reynolds number from pressure gradients are well within 5 %. It is found that the friction coefficients predicted by the model with electrokinetic effect are higher than that predicted by the macroscale fluid theory in the same microchannel. Stronger deviations are observed as the solution concentration decreases.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2007年第4期522-528,共7页
Optics and Precision Engineering
基金
国家自然科学基金项目(No.10572053)
高等学校博士学科点专项科研基金资助课题(No.20040183057)
关键词
电动效应
摩擦系数
雷诺数
有限控制容积法
计算机仿真
electrokinetic effect
friction coefficient
Reynolds number
finite control volume scheme
computer simulation
