Extensional flows of polymer solutions in microfluidic converging/diverging geometries

  • Gareth H. McKinleyEmail author
  • Lucy E. Rodd
  • Mónica S. N. Oliverira
  • Justin Cooper-White


The effects of fluid elasticity in the flow of non-Newtonian fluids in microfluidic converging/diverging geometries are investigated. We investigate the structure and dynamics of inertio-elastic flow instabilities and elastic corner vortices which develop upstream of the contraction plane, and explore their dependence on the relative magnitudes of inertia and elastic stress generated by the high deformation rates in the contraction geometry. The results show that the shape, size and evolution of these flow structures varies with the elasticity number, which is independent of the flow kinematics and is only dependent on fluid properties (viscosity, density and polymer relaxation time) and the characteristic size of the channel.

Key words

extensional rheology microfluidic extra pressure drop PEO Couette correction 


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  1. [1]
    SQUIRES T M, QUAKE S R. Microfluidics: fluid physics at the nanoliter scale[J]. Rev Mod Phys, 2005, 77(3): 977–1026.CrossRefGoogle Scholar
  2. [2]
    RODD L E, SCOTT T P, BOGER D V, et al. Planar entry flow of low viscosity elastic fluids in micro-fabricated geometries[J]. J Non-Newt Fluid Mech, 2005, 129(1): 1–22.CrossRefGoogle Scholar
  3. [3]
    QUAKE S R, SCHERER A. From micro-to nanofabrication with soft materials[J]. Science, 2000, 290(5496): 1536–1540.CrossRefGoogle Scholar
  4. [4]
    ROTHSTEIN J P, MCKINLEY G H. The axisymmetric contraction-expansion: the role of extensional rheology on vortex growth dynamics and the enhanced pressure drop[J]. J Non-Newt Fluid Mech, 2001, 98(1): 33–63.CrossRefGoogle Scholar
  5. [5]
    JAMES D F, SARINGER J H. Extensional flow of dilute polymer solutions[J]. J Fluid Mech, 1980, 97(4): 655–671.CrossRefGoogle Scholar
  6. [6]
    RODD L E, SCOTT T P, COOPER-WHITE J J, et al. Capillary breakup rheometry of low-viscosity elastic fluids[J]. Appl Rheol, 2005, 15(1): 12–27.CrossRefGoogle Scholar
  7. [7]
    MEINHART C D, WERELEY S T, GRAY M H B. Volume illumination for two-dimensional particle image velocimetry[J]. Meas Sci Tech, 2000, 11(6): 809–814.CrossRefGoogle Scholar
  8. [8]
    HULSEN M A. Numerical simulation of the diverging flow in a circular contraction of a viscoelastic fluid[J]. Theor Comput Fluid Dyn, 1993, 5(1): 33–48.CrossRefGoogle Scholar
  9. [9]
    JAMES D F, CHANDLER G M, ARMOUR S J. A Converging channel rheometer for the measurement of extensional viscosity[J]. J Non-Newt Fluid Mech, 1990, 35(2/3): 421–443.CrossRefGoogle Scholar

Copyright information

© Central South University Press, Sole distributor outside Mainland China: Springer 2007

Authors and Affiliations

  • Gareth H. McKinley
    • 1
    Email author
  • Lucy E. Rodd
    • 1
    • 2
  • Mónica S. N. Oliverira
    • 1
  • Justin Cooper-White
    • 3
  1. 1.Hatsopoulos Microfluids Laboratory, Department of Mechanical EngineeringMITCambridgeUSA
  2. 2.Department of Chemical and Biomolecular EngineeringThe University of MelbourneAustralia
  3. 3.Division of Chemical EngineeringThe University of QueenslandBrisbaneAustralia

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