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Electroviscous Effects in Low Reynolds Number Flow through a Microfluidic Contraction with Rectangular Cross-Section

Authors: Malcolm R Davidson, Ram P. Bharti, Petar Liovic, Dalton J.E. Harvie


The electrokinetic flow resistance (electroviscous effect) is predicted for steady state, pressure-driven liquid flow at low Reynolds number in a microfluidic contraction of rectangular cross-section. Calculations of the three dimensional flow are performed in parallel using a finite volume numerical method. The channel walls are assumed to carry a uniform charge density and the liquid is taken to be a symmetric 1:1 electrolyte. Predictions are presented for a single set of flow and electrokinetic parameters. It is shown that the magnitude of the streaming potential gradient and the charge density of counter-ions in the liquid is greater than that in corresponding two-dimensional slit-like contraction geometry. The apparent viscosity is found to be very close to the value for a rectangular channel of uniform cross-section at the chosen Reynolds number (Re = 0.1). It is speculated that the apparent viscosity for the contraction geometry will increase as the Reynolds number is reduced.

Keywords: Contraction, Electroviscous, Microfluidic, Numerical.

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[1] G. Whitesides and A. Stroock, "Flexible methods for microfluidics," Phys. Fluids, vol. 54, no. 6, pp. 42-48, 2001.
[2] M. Gad-El-Hak (ed.), The MEMS Handbook, second edition, CRC Press, Boca Raton, 2006.
[3] H. A. Stone and S. Kim, "Microfluidics: basic issues, applications, and challenges," AIChE J., vol. 47. No. 6, pp. 1250-1254, 2001
[4] H. A. Stone, A.D. Stroock and A. Ajdari, "Engineering flows in small devices: microfluidics towards a lab-on-a-chip," Annu. Rev. Fluid Mech., vol. 36, pp. 381-411, 2004.
[5] D. Li, Electrokinetics in Microfluidics. Interface Science and Technology, Vol. 2 (ed. A. Hibbard), Academic Press, 2004.
[6] R.J. Hunter, Zeta Potential in Colloid Science: Principles and Application. Academic Press, New York, 1981.
[7] G.M. Mala, D. Li and J.D. Dale, "Heat transfer and fluid flow in microchannels," Int. J. Heat Mass Transfer, vol. 40, pp. 3079-3088, 1997.
[8] G.M. Mala, D. Li, C. Werner and H. Jacobasch, "Flow characteristics of water through a microchannel between two parallel plates with electrokinetic effects," Int. J. Heat and Fluid Flow, vol. 18, no. 5, pp. 489-496, 1997
[9] M. Chun and H.W. Kwak, "Electrokinetic flow and electroviscous effect in a charged slit-like microfluidic channel with nonlinear Poisson- Boltzmann field," Korea-Australia Rheology J., vol. 15, no. 2, pp. 83- 90, 2003.
[10] W.R. Bowen and F. Jenner, "Electroviscous effects in charged capillaries," J. Coll. Interface Sci., vol. 173, pp. 388-395, 1995.
[11] D. Brutin and L. Tadrist, "Modeling of surface-fluid electrokinetic coupling on the laminar flow friction factor in microtubes," Microscale Thermophysical Engineering, vol.9, pp. 33-48, 2005.
[12] J. Hsu, C. Kao, S. Tseng, and C. Chen, "Electrokinetic flow through an elliptical microchannel: Effects of aspect ratio and electrical boundary conditions," J. Coll. Interface Sci., vol. 248, pp. 176-184, 2002.
[13] L. Ren, D. Li and W. Qu, "Electro-viscous effects on liquid flow in microchannels," J. Coll. Interface Sci., vol. 233, pp. 12-22, 2001.
[14] D. Li, "Electro-viscous effects on pressure-driven liquid flow in microchannels," Colloids and Surfaces A, vol. 195, pp. 35-57, 2001.
[15] M.R. Davidson and D.J.E. Harvie, "Electroviscous effects in low Reynolds number liquid flow through a slit-like microfluidic contraction," Chem. Eng. Sci., vol. 62, pp. 4229-4240, 2007.
[16] M.R. Davidson, D.J.E. Harvie and P. Liovic, "Electrokinetic flow resistance in pressure-driven liquid flow through a slit-like microfluidic contraction," in Proc. 16th Australasian Fluid Mechanics Conf., Gold Coast, Australia, 2-7 Dec. 2007, pp. 798-802.
[17] R.P. Bharti, D.J.E. Harvie and M.R. Davidson, "Steady flow of ionic liquid through a cylindrical microfluidic contraction-expansion pipe: Electroviscous effects and pressure drop," Chem. Eng. Sci, accepted for publication.
[18] M. Rudman, "A volume-tracking method for incompressible multifluid flows with large density variations," Int. J. for Numerical Methods in Fluids, vol. 28, pp. 357-378, 1998.
[19] D.J.E Harvie, M.R. Davidson, J.J. Cooper-White and M. Rudman, "A parametric study of droplet deformation through a microfluidic contraction: Shear thinning liquids," Int. J. Multiphase Flow, vol. 33, pp. 545-556, 2007.
[20] P.Liovic, D.Lakehal, "Multi-physics treatment in the vicinity of arbitrarily deformable gas-liquid interfaces, " J. Comput. Phys., vol. 222, pp. 504-535, 2007.