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Stability of miscible core–annular flows with viscosity stratification

Published online by Cambridge University Press:  14 November 2007

B. SELVAM
Affiliation:
Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106, USA
S. MERK
Affiliation:
Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106, USA
RAMA GOVINDARAJAN
Affiliation:
Engineering Mechanics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560 064, India
E. MEIBURG*
Affiliation:
Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106, USA
*
Author to whom correspondence should be addressed.

Abstract

The linear stability of variable viscosity, miscible core–annular flows is investigated. Consistent with pipe flow of a single fluid, the flow is stable at any Reynolds number when the magnitude of the viscosity ratio is less than a critical value. This is in contrast to the immiscible case without interfacial tension, which is unstable at any viscosity ratio. Beyond the critical value of the viscosity ratio, the flow can be unstable even when the more viscous fluid is in the core. This is in contrast to plane channel flows with finite interface thickness, which are always stabilized relative to single fluid flow when the less viscous fluid is in contact with the wall. If the more viscous fluid occupies the core, the axisymmetric mode usually dominates over the corkscrew mode. It is demonstrated that, for a less viscous core, the corkscrew mode is inviscidly unstable, whereas the axisymmetric mode is unstable for small Reynolds numbers at high Schmidt numbers. For the parameters under consideration, the switchover occurs at an intermediate Schmidt number of about 500. The occurrence of inviscid instability for the corkscrew mode is shown to be consistent with the Rayleigh criterion for pipe flows. In some parameter ranges, the miscible flow is seen to be more unstable than its immiscible counterpart, and the physical reasons for this behaviour are discussed.

A detailed parametric study shows that increasing the interface thickness has a uniformly stabilizing effect. The flow is least stable when the interface between the two fluids is located at approximately 0.6 times the tube radius. Unlike for channel flow, there is no sudden change in the stability with radial location of the interface. The instability originates mainly in the less viscous fluid, close to the interface.

Type
Papers
Copyright
Copyright © Cambridge University Press 2007

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References

REFERENCES

Bai, R., Chen, K. P. & Joseph, D. D. 1992 Lubricated pipelining: stability of core–annular flow. Part 5. Experiments and comparison with theory. J. Fluid Mech. 240, 97.CrossRefGoogle Scholar
Balasubramaniam, R. Rashidnia, N. Maxworthy, T. & Kuang, J. 2005 Instability of miscible interfaces in a cylindrical tube. Phys. Fluids 17, 052103.CrossRefGoogle Scholar
Boomkamp, P. A. M. & Miesen, R. H. M. 1996 Classification of instabilities in parallel two-phase flow. Intl J. Multiphase Flow 22, 67.CrossRefGoogle Scholar
Charru, F. & Hinch, E. J. 2000 ‘Phase diagram’ of interfacial instabilities in a two-layer Couette flow and mechanism for the long-wave instability. J. Fluid Mech. 414, 195.CrossRefGoogle Scholar
Chen, C.-Y. & Meiburg, E. 1996 Miscible displacement in capillary tubes. Part 2. Numerical simulations. J. Fluid Mech. 326, 57.CrossRefGoogle Scholar
Chen, K. P. 1993 Wave formation in a gravity-driven low Reynolds number flow of two liquid films down an inclined plane. Phys. Fluids A 5, 3038.CrossRefGoogle Scholar
Cox, B. G. 1962 On driving a viscous fluid out of a tube. J. Fluid. Mech. 14, 81.CrossRefGoogle Scholar
Drazin, P. G. & Reid, W. H. 1981 Hydrodynamic Stability. Cambridge University Press.Google Scholar
Ern, P., Charru, F. & Luchini, P. 2003 Stability analysis of a shear flow with strongly stratified viscosity. J. Fluid Mech. 496, 295.CrossRefGoogle Scholar
Govindarajan, R. 2004 Effect of miscibility on the linear instability of two-fluid channel flow. Intl J. Multiphase Flow 30, 1177.CrossRefGoogle Scholar
Govindarajan, R., L'vov, V. S. & Procaccia, I. 2001 Retardation of the onset of turbulence by minor viscosity contrasts. Phys. Rev. Lett. 87, 174501.CrossRefGoogle ScholarPubMed
Goyal, N. & Meiburg, E. 2006 Miscible displacements in Hele-Shaw cells: two-dimensional base states and their linear stability. J. Fluid Mech. 558, 329.CrossRefGoogle Scholar
Hickox, C. E. 1971 Instability due to viscosity and density stratification in axisymmetric pipe flow. Phys. Fluids 14, 251.CrossRefGoogle Scholar
Hinch, E. J. 1984 A note on the mechanism of the instability at the interface between two shearing fluids. J. Fluid Mech. 144, 463.CrossRefGoogle Scholar
Hooper, A. P. & Boyd, W. G. C. 1983 Shear-flow instability at the interface between two fluids. J. Fluid Mech. 128, 507.CrossRefGoogle Scholar
Hu, H. H. & Joseph, D. D. 1989 Lubricated pipelining: stability of core–annular flow. Part 2. J. Fluid Mech. 205, 359.CrossRefGoogle Scholar
Hu, H. H. & Patankar, N. 1995 Non-axisymmetric instability of core–annular flow. J. Fluid Mech. 290, 213.CrossRefGoogle Scholar
Hu, H. H., Lundgren, T. S. & Joseph, D. D. 1990 Stability of core–annular flow with a small viscosity ratio. Phys. Fluids A 2 (11), 1945.CrossRefGoogle Scholar
Jiang, W. Y., Helenbrook, B. & Lin, S. P. 2004 Inertialess instability of a two-layer liquid film flow. Phys. Fluids 16 (3), 652.CrossRefGoogle Scholar
Joseph, D. D. & Renardy, Y. Y. 1992 Fundamentals of Two-Fluid Dynamics. Part II: Lubricated Transport, Drops and Miscible Liquids. Springer.Google Scholar
Joseph, D. D., Renardy, Y. & Renardy, M. 1984 Instability of the flow of immiscible liquids with different viscosities in a pipe. J. Fluid Mech. 141, 319.CrossRefGoogle Scholar
Joseph, D. D., Bai, R., Chen, K. P. & Renardy, Y. Y. 1997 Core–annular flows. Annu. Rev. Fluid Mech. 29, 65.CrossRefGoogle Scholar
Khorrami, M. R. 1991 A Chebyshev spectral collocation method using a staggered grid for the stability of cylindrical flows. Intl J. Numer. Meth. Fluids 12, 825.CrossRefGoogle Scholar
Khorrami, M. R., Malik, M. R. & Ash, R. L. 1989 Application of spectral collocation techniques to the stability of swirling flows. J. Comput. Phys. 81, 206.CrossRefGoogle Scholar
Kouris, C. & Tsamopoulos, J. 2001 a Core–annular flow in a periodically constricted circular tube. Part 1. Steady-state linear stability and energy analysis. J. Fluid Mech. 432, 31.CrossRefGoogle Scholar
Kouris, C. & Tsamopoulos, J. 2001 b Dynamics of axisymmetric core–annular flow in a straight tube. i. The more viscous fluid in the core, bamboo waves. Phys. Fluids 13 (4), 841.CrossRefGoogle Scholar
Kouris, C. & Tsamopoulos, J. 2002 a Core–annular flow in a periodically constricted circular tube. Part 2. Nonlinear dynamics. J. Fluid Mech. 470, 181.CrossRefGoogle Scholar
Kouris, C. & Tsamopoulos, J. 2002 b Dynamics of axisymmetric core–annular flow in a straight tube. ii. The less viscous fluid in the core, saw tooth waves. Phys. Fluids 14 (3), 1011.CrossRefGoogle Scholar
Kuang, J., Maxworthy, T. & Petitjeans, P. 2003 Miscible displacements between silicone oils in capillary tubes. Eur. J. Mech. 22, 271.CrossRefGoogle Scholar
Li, J. & Renardy, Y. Y. 1999 Direct simulation of unsteady axisymmetric core–annular flow with high viscosity ratio. J. Fluid Mech. 391, 123.CrossRefGoogle Scholar
Loewenherz, D. S. & Lawrence, C. J. 1989 The effect of viscosity stratification on the instability of a free surface flow at low Reynolds number. Phys. Fluids A 1, 1686.CrossRefGoogle Scholar
Mack, I. M. 1976 A numerical study of the temporal eigenvalue spectrum of Blasius boundary layer flow. J. Fluid Mech. 73, 497.CrossRefGoogle Scholar
Malik, S. V. & Hooper, A. P. 2005 Linear stability and energy growth of viscosity stratified flows. Phys. Fluids 17, 024101.CrossRefGoogle Scholar
Panton, R. L. 1984 Incompressible Flow. John Wiley.Google Scholar
Petitjeans, P. & Maxworthy, T. 1996 Miscible displacements in capillary tubes. Part 1. Experiments. J. Fluid Mech. 326, 37.CrossRefGoogle Scholar
Preziosi, L., Chen, K. & Joseph, D. D. 1989 Lubricated pipelining: stability of core–annular flow. J. Fluid Mech. 201, 323.CrossRefGoogle Scholar
Ranganathan, B. T. & Govindarajan, R. 2001 Stabilization and destabilization of channel flow by the location of viscosity-stratified fluid layer. Phys. Fluids 13 (1), 13.CrossRefGoogle Scholar
Riaz, A., Pankiewitz, C. & Meiburg, E. 2004 Linear stability of radial displacements in porous media: influence of velocity-induced dispersion and concentration-dependent diffusion. Phys. Fluids 16 (10), 3592.CrossRefGoogle Scholar
Sahu, K. C. & Govindarajan, R. 2005 Stability of flow through a slowly diverging pipe. J. Fluid Mech. 531, 325.CrossRefGoogle Scholar
Schmid, P. J. & Henningson, D. S. 2001 Stability and Transition in Shear Flows. Springer.CrossRefGoogle Scholar
Scoffoni, J., Lajeunesse, E. & Homsy, G. M. 2001 Interface instabilities during displacements of two miscible fluids in a vertical pipe. Phys. Fluids 13 (3), 553.CrossRefGoogle Scholar
Smith, M. K. 1990 The mechanism for the long-wave instability in thin liquid films. J. Fluid Mech. 217, 469.CrossRefGoogle Scholar
Tan, C. T. & Homsy, G. M. 1986 Stability of miscible displacements: rectilinear flow. Phys. Fluids 29, 73549.CrossRefGoogle Scholar
Taylor, G. I. 1960 Deposition of a viscous fluid on the wall of a tube. J. Fluid Mech. 10, 161.CrossRefGoogle Scholar
Vanaparthy, S. H., Barthe, C. & Meiburg, E. 2006 Density-driven instabilities in capillary tubes: influence of a variable diffusion coefficient. Phys. Fluids 18, 048101.CrossRefGoogle Scholar
Wei, H. H. & Rumschitzki, D. S. 2002 a The linear stability of a core–annular flow in an asymptotically corrugated tube. J. Fluid Mech. 466, 113.CrossRefGoogle Scholar
Wei, H. H. & Rumschitzki, D. S. 2002 b The weakly nonlinear interfacial stability of a core–annular flow in a corrugated tube. J. Fluid Mech. 466, 149.Google Scholar
Yih, C.-S. 1967 Instability due to viscous stratification. J. Fluid Mech. 27, 337.CrossRefGoogle Scholar