摘要
为了有效控制和优化设计微流控芯片的驱动系统,考虑平板微管道内借助导电流体电渗流动拖动非导电流体流动的双层瞬态电渗流。首先根据静电学理论和流体力学理论,建立双层瞬态柯西动量方程,利用拉普拉斯变换法首次求解出瞬态解析解;其次,讨论不同电动宽度下双层速度和流量分布随时间的变化,发现壁面附近导电流体先获得速度,再带动整体导电流体以及非导电流体向前流动,液-液界面黏性效应消耗部分导电流体电渗流的动量,从而双层电渗流呈现抛物型速度剖面,速度最高值发生在导电流体区域内。且电动宽度对导电流体流动速度和流量的影响更为显著。另外,当无量纲时间达到O(1)时,瞬态流动基本进入稳态。
To achieve the precise control and optimum design of pumping system,the transient two-layer electroosmotic flow in a slit microchannel is studied where the nonconducting fluid is driven by the electroosmosis force of conducting fluid.At first,according to electrostatic theory and fluid mechanics,the two-layer transient Cauchy momentum equations are constructed,which are firstly solved by means of Laplace transform to present the analytical solutions.Then the two-layer velocities and flow rates at different electrokinetic width and different times are discussed.It turns out that the fluid near the solid wall of microchannel is set in motion at first and then the bulk conducting fluid together with the nonconducting fluid moves forward.The two-layer velocity profile shows parabolic and deviated toward the channel wall because the delivered momentum of conducting fluid is partly dissipated by the two-liquid viscous stress.And the maximum velocity occurs within the region of conducting fluid.Electrokinetic width plays more significant role in the velocity and flow rate of conducting fluid.Moreover,the transient flow tends to be in a steady status when the dimensionless time approaches to the order of O(1).
作者
卢锦华
石晓君
胡凯燕
邓曙艳
LU Jinhua;SHI Xiaojun;HU Kaiyan;DENG Shuyan(College of Architectural Engineering,Guangdong University of Petrochemical Technology,Maoming 525000,China)
出处
《广东石油化工学院学报》
2022年第4期57-60,69,共5页
Journal of Guangdong University of Petrochemical Technology
基金
广东省自然科学基金面上项目(2021A1515012371)
国家自然科学基金青年项目(11902082)
广东省普通高校青年创新人才类项目(2018KQNCX165)。
关键词
双层瞬态电渗流
电动宽度
速度剖面
流量
导电流体
two-layer transient electroosmotic flow
electrokinetic width
velocity profile
flow rate
conducting fluid
