Transient electro-osmotic and pressure driven flows of two-layer fluids through a slit microchannel  

作　　者：Jie Su Yong-Jun Jian Long Chang Quan-Sheng Liu 

机构地区：[1]School of Mathematical Science, Inner Mongolia University [2]School of Mathematics and Statistics, Inner Mongolia University of Finance and Economics

出　　处：《Acta Mechanica Sinica》2013年第4期534-542,共9页力学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(11062005 and 11202092);Open Fund of State Key Laboratory of Nonlinear Mechanics,the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(NJYT-13-A02);the Natural Science Foundation of Inner Mongolia(2010BS0107 and 2012MS0107);the Research Start Up Fund for Excellent Talents at Inner Mongolia University(Z20080211);the support of Natural Science Key Fund of Inner Mongolia(2009ZD01);the Postgraduate Scientific Research Innovation Project of Inner Mongolia;the Enhancing Comprehensive Strength Project of Inner Mongolia University(14020202)

摘　　要：By method of the Laplace transform, this arti- cle presents semi-analytical solutions for transient electro- osmotic and pressure-driven flows （EOF/PDF） of two-layer fluids between microparallel plates. The linearized Poisson- Boltzmann equation and the Cauchy momentum equation have been solved in this article. At the interface, the Maxwell stress is included as the boundary condition. By numerical computations of the inverse Laplace transform, the effects of dielectric constant ratio e, density ratio p, pressure ratio p, viscosity ratioμ of layer II to layer I, interface zeta potential difference △ψ, interface charge density jump Q, the ratios of maximum electro-osmotic velocity to pressure velocity , and the normalized pressure gradient B on transient veloc- ity amplitude are presented.We find the velocity amplitude becomes large with the interface zeta potential difference and becomes small with the increase of the viscosity. The ve- locity will be large with the increases of dielectric constant ratio; the density ratio almost does not influence the EOF ve- locity. Larger interface charge density jump leads to a strong jump of velocity at the interface. Additionally, the effects of the thickness of fluid layers （hi and h2） and pressure gradient on the velocity are also investigated.By method of the Laplace transform, this arti- cle presents semi-analytical solutions for transient electro- osmotic and pressure-driven flows （EOF/PDF） of two-layer fluids between microparallel plates. The linearized Poisson- Boltzmann equation and the Cauchy momentum equation have been solved in this article. At the interface, the Maxwell stress is included as the boundary condition. By numerical computations of the inverse Laplace transform, the effects of dielectric constant ratio e, density ratio p, pressure ratio p, viscosity ratioμ of layer II to layer I, interface zeta potential difference △ψ, interface charge density jump Q, the ratios of maximum electro-osmotic velocity to pressure velocity , and the normalized pressure gradient B on transient veloc- ity amplitude are presented.We find the velocity amplitude becomes large with the interface zeta potential difference and becomes small with the increase of the viscosity. The ve- locity will be large with the increases of dielectric constant ratio; the density ratio almost does not influence the EOF ve- locity. Larger interface charge density jump leads to a strong jump of velocity at the interface. Additionally, the effects of the thickness of fluid layers （hi and h2） and pressure gradient on the velocity are also investigated.

关 键 词：Hydromechanics ~ Micro-parallel plates ~ Elec-tric double layer （EDL） ~ Unsteady EOF/PDF ~ Two-layerNewtonian fluids 

分 类 号：TQ021.1[化学工程]