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Electrokinetically driven fluidic transport of power-law fluids in rectangular microchannels

Vakili, M. A ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1016/j.colsurfa.2012.07.030
  3. Publisher: 2012
  4. Abstract:
  5. Electroosmosis is the predominant mechanism for flow generation in lab-on-chip devices. Since most biofluids encountered in these devices are considered to be non-Newtonian, it is vital to study the flow characteristics of common non-Newtonian models under electroosmotic body force. In this paper, the hydrodynamically fully developed electroosmotic flow of power-law fluids in rectangular microchannels is analyzed. The electrical potential and momentum equations are numerically solved through a finite difference procedure for a non-uniform grid. A thoroughgoing parametric study reveals that the Poiseuille number is an increasing function of the channel aspect ratio, the zeta potential, the flow behavior index, and the dimensionless Debye-Hückel parameter. It is also found that the validity range of the Debye-Hückel approximation for shear-thickening fluids is much wider than that of shear-thinnings. Furthermore, while the dimensionless mean velocity is an increasing function of the channel aspect ratio and the dimensionless Debye-Hückel parameter, it is a decreasing function of the flow behavior index. Moreover, to increase the zeta potential is to increase the dimensionless mean velocity for shear-thinnings, nevertheless, its effect is not significant for shear-thickenings
  6. Keywords:
  7. Power-law fluids ; Biofluids ; Body forces ; Decreasing functions ; Electrical potential ; Electroosmotic ; Electroosmotic flow ; Finite difference ; Flow behavior index ; Flow characteristic ; Increasing functions ; Lab-on-chip devices ; Mean velocities ; Momentum equation ; Non-newtonian ; Non-Newtonian models ; Non-uniform grids ; Parametric study ; Poiseuille numbers ; Power law fluid ; Rectangular microchannels ; Shear-thickening fluids ; Aspect ratio ; Microchannels ; Microfluidics ; Non Newtonian flow ; Shear flow ; Transport properties ; Electric potential ; Electroosmosis ; Fluid transport ; Hydrodynamics ; Priority journal ; Velocity ; Zeta potential
  8. Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 414 , 2012 , Pages 440-456 ; 09277757 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0927775712005195