Detailed description of electro-osmotic effect on an encroaching fluid column inside a narrow channel

[+] Author and Article Information
Rakhitha Udugama

Department of Mechanical Engineering, Texas Tech University, Lubbock, TX-79409

Sukalyan Bhattacharya

Department of Mechanical Engineering, Texas Tech University, Lubbock, TX-79409

1Corresponding author.

ASME doi:10.1115/1.4039708 History: Received May 15, 2017; Revised February 28, 2018


This paper uses eigen expansion technique to describe electro-osmotic effect on unsteady intrusion of a viscous liquid driven by capillary action in a narrow channel. It shows how the dynamics can be manipulated by imposing an electric field along the flow-direction in presence of free charges. Similar manipulation can generate controlled transiency in motion of a complex fluid in a tube by non-destructive forcing leading to efficient rheological measurement. Existing theories analyze similar phenomena by accounting for all involved forces among which the viscous contribution is calculated assuming a steady velocity profile. However, if the transport is strongly transient, a new formulation without an underlying quasi-steady assumption is needed for accurate prediction of the time-dependent penetration. Such rigorous mathematical treatment is presented in this article where an eigen function expansion is used to represent the unsteady flow. Then, a system of ordinary differential equations is derived from which the unknown time-dependent amplitudes of the expansion are determined along with the temporal variation in encroached length. The outlined methodology is applied to solve problems with both constant and periodically fluctuating electric field. In both cases, simplified and convenient analytical models are constructed to provide physical insight into numerical results obtained from the full solution scheme. The detailed computations and the simpler reduced model corroborate each other verifying accuracy of the former and assuring utility of the latter. Thus, the theoretical findings can render a new rheometric technology for effective determination of fluid properties.

Copyright (c) 2018 by ASME
Your Session has timed out. Please sign back in to continue.






Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In