Transient solute dispersion in electro‐osmotic viscoplastic flow in a microchannel

Beg, OA; Roy, Ashis Kumar; Debnath, Sudip

Abstract

The transport of a neutral solute in incompressible electro-osmotic flow of Bingham plastic
non-Newtonian liquid flowing through a microchannel is studied theoretically. The flow is driven by a
constant axially applied electric field. The non-dimensional conservation equations with associated
boundary conditions are solved with Gill’s series expansion technique. The whole dispersion transport
process is analyzed using three transport coefficients, viz., advection coefficient, dispersion coefficient
and the apparent asymmetry coefficient, respectively. The mean concentration distribution of the solute
is calculated via a third-order approximation of the series expansion. The study investigates the
collective effects of yield stress and Electric Double Layer (EDL) thickness (inverse Debye length) on
the transport of solute. The long-term behaviour of mean concentration distribution is shown to be
accurately predicted by second-order approximations; however utilizing third or higher order
approximations in Gill's series expansion enables a more refined analysis of the small and moderate
time behavior of transport coefficients. The present analysis is relevant to emerging applications in biomicrofluidics exploiting electroviscous fluent media.

Citation

Beg, O., Roy, A. K., & Debnath, S. (2023). Transient solute dispersion in electro‐osmotic viscoplastic flow in a microchannel. ZAMM, 103(6), https://doi.org/10.1002/zamm.202200260

• Journal Article Type: Article
• Acceptance Date: Dec 15, 2022
• Online Publication Date: Jan 30, 2023
• Publication Date: Jan 30, 2023
• Deposit Date: Jan 9, 2023
• Publicly Available Date: Jan 31, 2024
• Journal: ZAMM - Journal of Applied Mathematics and Mechanics / Zeitschrift für Angewandte Mathematik und Mechanik
• Print ISSN: 0044-2267
• Electronic ISSN: 1521-4001
• Publisher: Wiley-VCH Verlag
• Volume: 103
• Issue: 6
• DOI: https://doi.org/10.1002/zamm.202200260
• Keywords: Applied Mathematics, Computational Mechanics
• Publisher URL: https://doi.org/10.1002/zamm.202200260
• Additional Information: Additional Information : This is the peer reviewed version of the following article: Roy, A.K., Debnath, S., Bég, O.A.: Transient solute dispersion in electro-osmotic viscoplastic flow in a microchannel. Z Angew Math Mech. 00, e202200260 (2023)., which has been published in final form at https://doi.org/10.1002/zamm.202200260. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.