微平行管道内Jeffrey流体的非定常电渗流动

研究了微平行管道内线性黏弹性流体的非定常电渗流动, 其中线性黏弹性流体的本构关系是由Jeffrey流体模型来描述的. 利用Laplace变换法, 求解了线性化的Poisson-Boltzmann方程、 非定常的柯西动量方程和Jeffrey流体本构方程, 给出了黏弹性Jeffrey流体电渗速度的解析表达式, 分析了无量纲弛豫时间λ₁和滞后时间λ₂对速度剖面的影响. 发现滞后时间为零时, 弛豫时间越小, 速度剖面图越接近牛顿流体的速度剖面图; 随着弛豫时间和滞后时间的增加, 速度振幅也变得越来越大, 随着时间的增加, 速度逐渐趋于恒定. 关键词： 双电层 微平行管道 Jeffrey流体 非定常电渗流动

Transient electroosmotic flow of general Jeffrey fluid between two micro-parallel plates

In this study, analytical solutions are presented for the unsteady electroosmotic flow of linear viscoelastic fluid between micro-parallel plates. The linear viscoelastic fluid used here is described by the general Jeffrey model. Using Laplace transform method, the solution involves analytically solving the linearized Poisson-Boltzmann equation, together with the Cauchy momentum equation and the general Jeffrey constitutive equation. By numerical computations, the influences of the dimensionless relaxation time λ₁ and retardation time λ₂ on velocity profile are presented. In addition, we find that when the retardation time is zero, the smaller the relaxation time, the more close to the Newtonian fluid velocity profile the velocity profile is. With the increases of the relaxation time and the retardation time, the velocity amplitude also becomes bigger and bigger. As time goes by, the velocity tends to be stable gradually.
Keywords： electric double-layer micro-parallel plates Jeffrey fluids unsteady electroosmotic flow