Simulation of Fluid Mixing in Microchannel Under Heterogeneous Zeta-Potential Effect by Lattice-Boltzmann Method

In this study, we use the lattice Boltzmann method to implement 2-D and 3-D numerical simulations to investigate the electrokinetic effect on the fluid flow and mixing in a rectangular microchannel. Zeta-potential is employed as the main factor representing the electrokinetic effect. The numerical simulations aim at two new designs of electrode distribution in the microchannel. One uses the periodically distributed rectangular electrodes on both sides of the walls of the microchannel, in which 2D and 3D simulations were implemented with time periodic application of the electric potential on the electrodes. In another model, periodic array of trapezoidal electrodes were attached on the bottom walls, and 3D simulation was carried out with constant zeta-potential on the electrodes. The simulation results of the second design model by LBM have been compared with those obtained by CFX and good agreement was obtained. Through the parametric studies for both designs, it was shown that there exists an optimum parameter value leading to the best mixing performance.