Chaotic mixing in a microchannel utilizing periodically switching electro-osmotic recirculating rolls.
In this study, active mixing in a microchannel with spatiotemporal variations in zeta potential distributions was investigated theoretically. In this mixing system, the primary flow is a pressure-driven flow (i.e., parabolic flow), and the electro-osmotic recirculating rolls induced by the heterogeneous zeta potential distributions act as the perturbation source. By timewise alterations of two different electro-osmotic recirculating flow fields, chaotic mixing can be induced. Blob deformation, Poincaré map, and Lyapunov exponent analyses were employed to describe the behaviors of the particle motion in this active mixing system. Finally, the optimal time-switching period was identified, which was also verified through direct numerical simulations.
Chang
Chih-Chang
CC
Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan 701.
Yang
Ruey-Jen
RJ