Unsteady viscous flow driven by the combined effects of peristalsis and electro-osmosis

Tripathi, D; Bushan, S; Beg, OA

Abstract

Electrokinetic transport of fluids through micro-channels by micro-pumping and micro- peristaltic pumping has stimulated considerable interest in biomedical engineering and other areas of medical technology. Deeper elucidation of the fluid dynamics of such transport requires the continuous need for more elegant mathematical models and numerical simulations, in parallel with laboratory investigations. In this article we therefore investigate analytically the unsteady viscous flow driven by the combined effects of peristalsis and electro-osmosis through microchannel. An integral number of waves propagating in the microchannel is considered as a model for transportation of fluid bolus along the channel length. Debye-Hückel linearization is employed to evaluate the potential function. Low Reynolds number and large wavelength approximations are employed. Closed-form solutions are derived for the non-dimensional boundary value problem. The computations demonstrate that magnitude of electric potential function is increased with a decrease in the thickness of the electrical double layer (EDL). Stronger electric field also decelerates the flow and decreases local wall shear stress. Hydrodynamic pressure is increased with EDL thickness whereas it is suppressed with electric field. Streamline visualization reveals that the quantity of trapped bolus is decreased with increasing EDL thickness and also with higher external electric field.

• Journal Article Type: Article
• Acceptance Date: May 21, 2017
• Online Publication Date: Jun 21, 2017
• Publication Date: Jun 21, 2017
• Deposit Date: May 23, 2017
• Publicly Available Date: Jun 27, 2017
• Journal: Alexandria Engineering Journal
• Print ISSN: 1110-0168
• Publisher: Elsevier
• Volume: 57
• Issue: 3
• Pages: 1349-1359
• DOI: https://doi.org/10.1016/j.aej.2017.05.027
• Publisher URL: http://dx.doi.org/10.1016/j.aej.2017.05.027
• Related Public URLs: https://www.journals.elsevier.com/alexandria-engineering-journal/