Electroosmotic flow in a microchannel containing a porous medium with complex wavy walls

Tripathi, D; Bhushan, S; Beg, OA

Abstract

In present paper, we simulate the electro-kinetic transport of aqueous solution through a microchannel containing porous media. The micro-channel walls are simulated as complex wavy
surface and are modelled by superimposing the three wave functions of different amplitudes
but the same wavelength. The micro-channel contains an isotropic, homogenous porous
medium, which is analysed with a generalized Darcy law. The nonlinear-coupled governing
equations for mass, momentum and electrical potential conservation are simplified using low
Reynolds number and long wavelength approximations, and the Debye electro-kinetic
linearization. Following non-dimensional transformation of the linearized boundary value
problem, closed-form analytical solutions are presented for the velocity components, pressure
gradient, local wall shear stress, average flow rate and stream function subject to physically
appropriate boundary conditions. Validation with a finite difference method is also conducted.
The effect of permeability parameter, Debye length (i.e. characteristic thickness of electrical
double layer) and electro-osmotic velocity on flow characteristics is illustrated graphically and
interpreted at length. The study finds applications in chromatography, hybrid electro-osmotic
micro-pumps, transport phenomena in chemical engineering and energy systems exploiting
electro-kinetics.

Citation

Tripathi, D., Bhushan, S., & Beg, O. (2020). Electroosmotic flow in a microchannel containing a porous medium with complex wavy walls. Journal of Porous Media, 23(5), 477-495. https://doi.org/10.1615/JPorMedia.2020026114

• Journal Article Type: Article
• Acceptance Date: Nov 5, 2019
• Online Publication Date: May 29, 2020
• Publication Date: May 29, 2020
• Deposit Date: Nov 6, 2019
• Publicly Available Date: May 29, 2021
• Journal: Journal of Porous Media
• Print ISSN: 1091-028X
• Electronic ISSN: 1934-0508
• Publisher: Begell House
• Volume: 23
• Issue: 5
• Pages: 477-495
• DOI: https://doi.org/10.1615/JPorMedia.2020026114
• Publisher URL: https://doi.org/10.1615/JPorMedia.2020026114
• Related Public URLs: https://www.begellhouse.com/journals/porous-media.html