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Disturbance energy growth in core–annular flow

Published online by Cambridge University Press:  10 April 2014

A. Orazzo
Affiliation:
Dipartimento di Ingegneria Industriale, Università degli studi di Napoli ‘Federico II’, Naples, 80125, Italy
G. Coppola*
Affiliation:
Dipartimento di Ingegneria Industriale, Università degli studi di Napoli ‘Federico II’, Naples, 80125, Italy
L. de Luca
Affiliation:
Dipartimento di Ingegneria Industriale, Università degli studi di Napoli ‘Federico II’, Naples, 80125, Italy
*
Email address for correspondence: [email protected]

Abstract

The linear stability of the horizontal pipe flow of an equal density oil–water mixture, arranged as a core–annular flow (CAF), is here reconsidered from the point of view of non-modal analysis in order to assess the effects of non-normality of the linearized Navier–Stokes operator on the transient evolution of small disturbances. The aim of this investigation is to give insight into physical situations in which poor agreement occurs between the predictions of linear modal theory and classical experiments. The results exhibit high transient amplifications of the energy of three-dimensional perturbations and, in analogy with single-fluid pipe flow, the largest amplifications arise for non-axisymmetric disturbances of vanishing axial wavenumber. Energy analysis shows that the mechanisms leading to these transient phenomena mostly occur in the annulus, occupied by the less viscous fluid. Consequently, higher values of energy amplifications are obtained by increasing the gap between the core and the pipe wall and the annular Reynolds number. It is argued that these linear transient mechanisms of disturbance amplification play a key role in explaining the transition to turbulence of CAF.

Type
Papers
Copyright
© 2014 Cambridge University Press 

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References

Ash, R. L. & Khorrami, M. R. 1995 Vortex stability. In Fluid Vortices, pp. 317372. Kluwer.Google Scholar
Charles, M. E., Govier, G. W. & Hodgson, G. W. 1961 The horizontal pipeline flow of equal density oil–water mixtures. Can. J. Chem. Engng 39, 1736.CrossRefGoogle Scholar
Charles, M. E. & Redberger, P. J. 1962 The reduction of pressure gradients in oil pipelines by the addition of water: numerical analysis of stratified flow. Can. J. Chem. Engng 40 (2), 7075.CrossRefGoogle Scholar
Chen, K. & Joseph, D. D. 1991 Lubricated pipelining: stability of core–annular flow. Part 4. Ginzburg–Landau equations. J. Fluid Mech. 227, 226260.Google Scholar
Coppola, G., Orazzo, A. & de Luca, L. 2012 Non-modal instability of core–annular flow. Int. J. Nonlinear Sci. Numer. Simul. 13, 405415.Google Scholar
Coppola, G. & Semeraro, O. 2011 Interfacial instability of two rotating viscous immiscible fluids in a cylinder. Phys. Fluids 23, 064105.Google Scholar
Hickox, C. E. 1971 Instability due to viscosity and density stratification in axisymmetric pipe flow. Phys. Fluids 14, 251262.Google Scholar
Hu, H. H. & Joseph, D. D. 1989 Lubricated pipelining: stability of core–annular flow. Part 2. J. Fluid Mech. 205, 359396.Google Scholar
Joseph, D. D. & Renardy, Y. Y. 1991 Fundamentals of Two-Fluid Dynamics. Springer.Google Scholar
Joseph, D. D., Renardy, Y. & Renardy, M. 1985 Instability of the flow of immiscible liquids with different viscosities in a pipe. J. Fluid Mech. 141, 309317.Google 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, 206229.Google Scholar
MacLean, D. L. 1973 A theoretical analysis of bicomponent flow and the problem of interface shape. Trans. Soc. Rheol. 17, 385399.CrossRefGoogle Scholar
Malik, S. & Hooper, A. P. 2007 Three-dimensional disturbances in channel flows. Phys. Fluids 19, 052102.Google Scholar
Miesen, R., Beijnon, G., Duijvestijn, P. E. M., Oliemans, R. V. A. & Verheggen, T. 1992 Interfacial waves in core–annular flow. J. Fluid Mech. 238, 97117.Google Scholar
Oliemans, R. V. A. & Ooms, G. 1986 Core–annular flow of oil and water through a pipeline. Multiphase Sci. Technol. 2, 427476.Google Scholar
Papageorgiou, D. T., Maldarelli, C. & Rumschitzki, D. S. 1990 Nonlinear interfacial stability of core–annular film flows. Phys. Fluids A 2 (3), 340352.Google Scholar
Preziosi, L., Chen, K. & Joseph, D. D. 1989 Lubricated pipelining: stability of core–annular flow. J. Fluid Mech. 201, 323356.Google Scholar
Schmid, P. J. 2007 Non-modal stability theory. Annu. Rev. Fluid Mech. 39, 129162.CrossRefGoogle Scholar
Schmid, P. J. & Henningson, D. S. 1994 Optimal energy density growth in Hagen–Poiseuille flow. J. Fluid Mech. 277, 197225.Google Scholar
Schmid, P. J. & Henningson, D. S. 2001 Stability and Transition in Shear Flow. Springer.Google Scholar
Sotgia, G., Tartarini, P. & Stalio, E. 2008 Experimental analysis of flow regimes and pressure drop reduction in oil–water mixtures. Intl J. Multiphase Flow 34, 11611174.Google Scholar
Trefethen, L. N. & Embree, M. 2005 Spectra and Pseudospectra: The Behavior of Nonnormal Matrices and Operators. Princeton University Press.Google Scholar
Trefethen, L. N., Trefethen, A. E., Reddy, S. C. & Driscoll, T. A. 1993 Hydrodynamic stability without eigenvalues. Science 261, 578584.Google Scholar