Numerical Simulation of Electroosmotic Flow Path Selection in a Y-Shaped Triangle

Abstract

This research studied the switching process of an electroosmotic flow (EOF) in a Y-shape three-way microchannel by using analytical and numerical solutions. In the analytical study of the flow based on some proposed simplifying assumptions, equations were introduced to approximate the switching voltage ratio (λ) and EOF rate before and after the switching process. In the analyses, parameters “distance between outlet branches and the three-way” and “dimensionless thickness of the electrical double layer” were assumed to be flow variables, and their effects on the flow’s ultimate condition were evaluated. Numerically, the Lattice Boltzmann method (LBM) and Poisson-Boltzmann approximation were used to solve all the equations governing the EOF in a two-dimensional Y-shape three-way microchannel. When comparing the analytical and numerical results, approximated equations of the analytical side possessed noticeably high accuracy and outperformed the numerical side in approximating the EOF rate at considerably lower computational efforts.

Keywords: Electroosmotic flow, Flow switching, Lattice Boltzmann