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Equilibrium Position of a Buoyant Drop in Couette and Poiseuille Flows at Finite Reynolds Numbers

Published online by Cambridge University Press:  16 October 2012

M. Bayareh*
Affiliation:
Department of Mechanical Engineering, Young Researchers Club, Lamerd Branch, Islamic Azad University, Lamerd, Iran
S. Mortazavi
Affiliation:
Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran
*
*Corresponding author ([email protected])
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Abstract

The equilibrium position of a deformable drop in Couette and Poiseuille flows is investigated numerically by solving the full Navier-Stokes equations using a finite difference/front tracking method. The objective of this work is to study the motion of a non-neutrally buoyant drop in Couette and Poiseuille flows with different density ratios at finite Reynolds numbers. Couette flow: The equilibrium position of the lighter drops is higher than the heavier drops at each particle Reynolds number. Also, the equilibrium position height increases with increasing the Reynolds number at a fixed density ratio. At this equilibrium distance from the wall, the migration velocity is zero, while the velocity of the drop in the flow direction and rotational velocity of the drop is finite. It is observed that the equilibrium position is independent of the initial position of the drops and depends on the density ratio and the shear Reynolds number. Poiseuille flow: When the drop is slightly buoyant, it moves to an equilibrium position between the wall and the centerline. The equilibrium position is close to the centerline if the drop lags the fluid but close to the wall if the drop leads the fluid. As the Reynolds number increases, the equilibrium position of lighter drops moves slightly closer to the wall and the equilibrium position of heavier drops moves towards the centerline.

Type
Articles
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2012

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References

REFERENCES

1. Segre, G. and Silberberg, A., “Behavior of Macroscopic Rigid Spheres in Poiseuille Flow. Part 1. Determination of Local Concentration by Statistical Analysis of Particles Passages Through Crossed Light Beams,” Journal of Fluid Mechanics, 14, pp. 115135 (1962).CrossRefGoogle Scholar
2. Mortazavi, S. and Tryggvason, G., “A Numerical Study of the Motion of Drop in Poiseuille Flow Part 1: Lateral Migration of One Drop,” Journal of Fluid Mechanics, 411, pp. 325350 (2000).CrossRefGoogle Scholar
3. Griggs, A. G., Zinchenko, A. Z. and Davis, R. H., “Low-Reynolds-Number Motion of a Deformable Drop Between Two Parallel Plane Walls,” International Journal of Multiphase Flow, 33, pp. 182206 (2007).Google Scholar
4. Doddi, S. K. and Bagchi, P., “Lateral Migration of a Capsule in a Plane Poiseuille in a Channel,” International Journal of Multiphase Flow, 34, pp. 966986 (2008).CrossRefGoogle Scholar
5. Loewenberg, M. and Hinch, E., “Numerical Simulation of a Concentrated Emulsion in Shear Flow,” Journal of Fluid Mechanics, 321, pp. 395419 (1996).Google Scholar
6. Feng, J., Hu, H. H. and Joseph, D. D., “Direct Simulation of Initial Value Problems for the Motion of Solid Bodies in a Newtonian Fluid. Part 2. Couette Flow and Poiseuille Flows,” Journal of Fluid Mechanics, 277, pp. 271301 (1994b).Google Scholar
7. Li, X., Zhou, H. and Pozrikidis, C., “A Numerical Study of the Shearing Motion of Emulsions and Foams,” Journal of Fluid Mechanics, 286, pp. 374404 (1995).Google Scholar
8. Bayareh, M. and Mortazavi, S., “Numerical Simulation of the Motion of a Single Drop in a Shear Flow at Finite Reynolds Numbers,” Journal of Iranian Science and Technology, 33, pp. 441452 (2009).Google Scholar
9. Bayareh, M. and Mortazavi, S., “Numerical Simulation of the Interaction of Two Equal-Size Drops in a Shear Flow at Finite Reynolds Numbers,” Proceeding of ISME2009 (international conference), Tehran, Iran, pp. 323324 (2009).Google Scholar
10. Bayareh, M. and Mortazavi, S., “Geometry Effects on the Interaction of Two Equal-Sized Drops in Couette Flow at Finite Reynolds Numbers,” 5th International Conference: Computational Methods in Multiphase Flow (WIT), 63, pp. 379388 (2009).Google Scholar
11. Bayareh, M. and Mortazavi, S., “Binary Collision of Drops in Simple Shear Flow at Finite Reynolds Numbers: Geometry and Viscosity Ratio Effects,” Journal of Advanced in Engineering Software, 42, pp. 604611 (2011),Google Scholar
12. Unverdi, S. O. and Tryggvason, G., “A Front Tracking Method for Viscous Incompressible Flows,” Journal of Computational Physics, 100, pp. 2537 (1992).Google Scholar
13. Tryggvason, G., Bunner, B., Esmaeeli, A., Juric, D., Al-rawahi, N., Tauber, W., Hans, J., Nas, S. and Jan, Y. J., “A Front-Tracking Method for the Computations of Multiphase Flow,” Journal of Computational Physics, 169, pp. 708759 (2001).Google Scholar
14. Feng, Z. G. and Michaelides, E. E., “Equilibrium Position for a Particle in a Horizontal Shear Flow,” International Journal of Multiphase Flow, 29, pp. 943957 (2003).Google Scholar
15. Kurose, R. and Komori, S., “Drag and Lift Forces on a Rotating Sphere in a Linear Shear Flow,” Journal of Fluid Mechanics, 384, pp. 263286 (2002).Google Scholar
16. Vasseur, P. and Cox, R. G., “The Lateral Migration of a Spherical Particle in Two-Dimensional Shear Flows,” Journal of Fluid Mechanics, 78, p. 385 (1976).Google Scholar