Print: | ISSN 0256-1115 |
Online: | ISSN 1975-7220 |
Korean Journal of Chemical Engineering,
Vol.29, No.2, 154-161, 2012 Electrokinetic effects on fluid flow and particle transport
The effect of counter-electroosmotic flow on the particle trajectories, the particle equilibrium position, and the critical flux was for the first time evaluated in normal flow filtration using numerical solution of the two-dimensional coupled Navier-Stokes, Nernst-Plank, and Poisson equations for a slit pore having a converging entrance. It was shown that the numerical results for the velocity profiles, ion concentrations, and induced streaming potential were in good agreement with analytical expressions obtained for a simple slit shaped. Numerical simulations for particle
transport were performed at both constant pressure and constant filtration velocity in the presence of counter-electroosmosis. A significant shift in the particle trajectory and final equilibrium location were shown at constant pressure due to the reduction in the filtrate flux associated with the counter-electroosmotic flow arising from the induced streaming potential. However, simulations conducted at a constant filtration velocity showed only a very small effect of counterelectroosmosis, with the equilibrium position varying by less than 5% for calculations performed in the presence/absence of counter-electroosmosis. This result stems from a very small distortion in the velocity profile in the region above the pore due to the greater contribution from counter-electroosmosis in the region immediately adjacent to the pore wall. This paper will provide a useful framework to evaluate particle transport in the presence of electrokinetic phenomena.
Keywords:
Counter-electroosmosis; Electrostatic Interaction; Particle Trajectory; Normal Flow Filtration; CFD Simulations
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