Start-up electroosmotic flow of Maxwell fluids in a rectangular microchannel with high zeta potentials

2016 ◽  
Vol 227 ◽  
pp. 17-29 ◽  
Author(s):  
E. Jiménez ◽  
J. Escandón ◽  
O. Bautista ◽  
F. Méndez
Keyword(s):  
Electroosmotic Flow ◽  
Rectangular Microchannel ◽  
Zeta Potentials ◽  
Maxwell Fluids ◽  
Start Up

Transient electroosmotic flow of Maxwell fluids in a slit microchannel with asymmetric zeta potentials

2015 ◽  
Vol 53 ◽  
pp. 180-189 ◽  
Author(s):  
J. Escandón ◽  
E. Jiménez ◽  
C. Hernández ◽  
O. Bautista ◽  
F. Méndez
Keyword(s):  
Electroosmotic Flow ◽  
Zeta Potentials ◽  
Maxwell Fluids

scholarly journals Start-Up Electroosmotic Flow of Multi-Layer Immiscible Maxwell Fluids in a Slit Microchannel

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 757
Author(s):  
Juan Escandón ◽  
David Torres ◽  
Clara Hernández ◽  
René Vargas
Keyword(s):  
Electroosmotic Flow ◽  
Relaxation Times ◽  
Solution Process ◽  
Momentum Equation ◽  
Oscillatory Behavior ◽  
Liquid Interfaces ◽  
Transform Method ◽  
Maxwell Fluids ◽  
Start Up ◽  
Density Ratios

In this investigation, the transient electroosmotic flow of multi-layer immiscible viscoelastic fluids in a slit microchannel is studied. Through an appropriate combination of the momentum equation with the rheological model for Maxwell fluids, an hyperbolic partial differential equation is obtained and semi-analytically solved by using the Laplace transform method to describe the velocity field. In the solution process, different electrostatic conditions and electro-viscous stresses have to be considered in the liquid-liquid interfaces due to the transported fluids content buffer solutions based on symmetrical electrolytes. By adopting a dimensionless mathematical model for the governing and constitutive equations, certain dimensionless parameters that control the start-up of electroosmotic flow appear, as the viscosity ratios, dielectric permittivity ratios, the density ratios, the relaxation times, the electrokinetic parameters and the potential differences. In the results, it is shown that the velocity exhibits an oscillatory behavior in the transient regime as a consequence of the competition between the viscous and elastic forces; also, the flow field is affected by the electrostatic conditions at the liquid-liquid interfaces, producing steep velocity gradients, and finally, the time to reach the steady-state is strongly dependent on the relaxation times, viscosity ratios and the number of fluid layers.

Exact Solution of the Start-Up Electroosmotic Flow of Generalized Maxwell Fluids in Triangular Microducts

2021 ◽  
Author(s):  
F.Talay Akyildiz ◽  
Dennis A. Siginer
Keyword(s):  
Exact Solution ◽  
Electroosmotic Flow ◽  
Fractional Derivatives ◽  
Maxwell Fluid ◽  
Solution Technique ◽  
Maxwell Fluids ◽  
Start Up ◽  
Triangular Region ◽  
Overshoot Phenomenon ◽  
Poisson Boltzmann

Abstract Unsteady electroosmotic flow of generalized Maxwell fluids in triangular microducts is investigated. The governing equation is formulated with Caputo-Fabrizio time-fractional derivatives whose orders are distributed in the interval [0, 1). The linear momentum and the Poisson-Boltzmann equations are solved analytically in tandem in the triangular region with the help of the Helmholtz eigenvalue problem and Laplace transforms. The analytical solution developed is exact. The solution technique we use is new, leads to exact solutions, is completely different from those available in the literature and is applicable to other similar problems. The new expression for the velocity field displays experimentally observed 'velocity overshoot' as opposed to existing analytical studies none of which can predict the overshoot phenomenon. We show that when Caputo-Fabrizio time-fractional derivatives approach unity the exact solution for the classical upper convected Maxwell fluid is obtained. The presence of elasticity in the constitutive structure alters the Newtonian velocity profiles drastically. The influence of pertinent parameters on the flow field is explored.

AC electroosmotic flow of generalized Maxwell fluids in a rectangular microchannel

2011 ◽  
Vol 166 (21-22) ◽  
pp. 1304-1314 ◽  
Author(s):  
Yong-jun Jian ◽  
Quan-sheng Liu ◽  
Lian-gui Yang
Keyword(s):  
Electroosmotic Flow ◽  
Rectangular Microchannel ◽  
Maxwell Fluids

Frequency-dependent laminar electroosmotic flow in a closed-end rectangular microchannel

2004 ◽  
Vol 275 (2) ◽  
pp. 679-698 ◽  
Author(s):  
Marcos ◽  
C. Yang ◽  
K.T. Ooi ◽  
T.N. Wong ◽  
J.H. Masliyah
Keyword(s):  
Electroosmotic Flow ◽  
Rectangular Microchannel ◽  
Frequency Dependent

Viscoelectric Effect on the Electroosmotic Flow in Nanochannels With Heterogeneous Zeta Potentials

2018 ◽  
Author(s):  
Edson M. Jimenez ◽  
Federico Méndez ◽  
Juan P. Escandón
Keyword(s):  
Electroosmotic Flow ◽  
Fluid Velocity ◽  
Volumetric Flow Rate ◽  
Mass Conservation ◽  
Double Layers ◽  
Fluid Viscosity ◽  
Governing Equations ◽  
Flat Plates ◽  
Zeta Potentials ◽  
Poisson Boltzmann

In the present work, we realize a study about the influence of viscoelectric effect on the electroosmotic flow of Newtonian fluids in nanochannels formed by two parallel flat plates. In the problem, the channel walls have heterogeneous zeta potentials which follow a sinusoidal distribution; moreover, viscoelectric effects appear into the electric double layers when high zeta potentials are considered at the channel walls, modifying the fluid viscosity and the fluid velocity. To find the solution of flow field, the modified Poisson-Boltzmann, mass conservation and momentum governing equations, are solved numerically. In the results, combined effects from the zeta potential heterogeneities and viscosity changes yields different kind of flow recirculations controlled by the dephasing angle, amplitude and number of waves of the heterogeneities at the walls. The viscoelectric effect produces a decrease in the magnitude of velocity profiles and volumetric flow rate when the high zeta potentials are magnified. Additionally, the heterogeneous zeta potentials at the walls generate an induced pressure on the flow. This investigation extend the knowledge of electroosmotic flows under field effects for future mixing applications.

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