A hydrodynamic bifurcation in electroosmotically-driven periodic flows
Abstract
In this paper we report a novel inertial instability that occurs in electro-osmotically driven channel flows. We assume that the charge motion under the influence of an externally applied electric field is confined to a small vicinity of the channel walls that, effectively, drives a bulk flow through a prescribed slip velocity at the boundaries. Here, we study spatially-periodic wall velocity modulations in a two-dimensional straight channel numerically. At low slip velocities, the bulk flow consists of a set of vortices along each wall that are left-right symmetric, while at sufficiently high slip velocities, this flow loses its stability though a supercritical bifurcation. Surprisingly, the new flow state that bifurcates from a left-right symmetric base flow has a rather strong mean component along the channel, which is similar to pressure-driven velocity profiles. The instability sets in at rather small Reynolds numbers of about 20-30, and we discuss its potential applications in microfluidic devices.
Cite
@article{arxiv.1708.07470,
title = {A hydrodynamic bifurcation in electroosmotically-driven periodic flows},
author = {Alexander Morozov and Davide Marenduzzo and Ronald G. Larson},
journal= {arXiv preprint arXiv:1708.07470},
year = {2018}
}
Comments
13 pages, 6 figures