Paper Info
Title
Modeling electrokinetic flows in microchannels using coupled lattice Boltzmann methods
Abstract
We present a numerical framework to solve the dynamic model for electrokinetic flows in microchannels using coupled lattice Boltzmann methods. The governing equation for each transport process is solved by a lattice Boltzmann model and the entire process is simulated through an iteration procedure. After validation, the present method is used to study the applicability of the Poisson-Boltzmann model for electrokinetic flows in microchannels. Our results show that for homogeneously charged long channels, the Poisson-Boltzmann model is applicable for a wide range of electric double layer thickness. For the electric potential distribution, the Poisson-Boltzmann model can provide good predictions until the electric double layers fully overlap, meaning that the thickness of the double layer equals the channel width. For the electroosmotic velocity, the Poisson-Boltzmann model is valid even when the thickness of the double layer is 10 times of the channel width. For heterogeneously charged microchannels, a higher zeta potential and an enhanced velocity field may cause the Poisson-Boltzmann model to fail to provide accurate predictions. The ionic diffusion coefficients have little effect on the steady flows for either homogeneously or heterogeneously charged channels. However the ionic valence of solvent has remarkable influences on both the electric potential distribution and the flow velocity even in homogeneously charged microchannels. Both theoretical analyses and numerical results indicate that the valence and the concentration of the counter-ions dominate the Debye length, the electrical potential distribution, and the ions transport. The present results may improve the understanding of the electrokinetic transport characteristics in microchannels.
Year
DOI
Venue
2010
10.1016/j.jcp.2009.10.006
J. Comput. Physics
Keywords
Field
DocType
dynamic model,channel width,electrical potential distribution,lattice boltzmann method,lattice boltzmann model,electric double layer,double layer,multiphysical transport,microfluidics and nanofluidics,poisson-boltzmann model,electric double layer thickness,electric potential distribution,electrokinetic flows,electrokinetic flow,poisson–boltzmann model,poisson boltzmann,zeta potential,diffusion coefficient,ion transport,velocity field,flow velocity
Statistical physics,Boltzmann equation,Mathematical analysis,Lattice Boltzmann methods,Debye length,Electric potential,Mechanics,Lattice model (finance),Flow velocity,Zeta potential,Electrokinetic phenomena,Mathematics
Journal
Volume
Issue
ISSN
229
3
Journal of Computational Physics
Citations 
PageRank 
References 
8
1.07
6
Authors
2
Name
Order
Citations
PageRank
Moran Wang1286.06
Qinjun Kang2183.77