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Capillary breakup of a liquid torus

Published online by Cambridge University Press:  01 February 2013

Hadi Mehrabian
Affiliation:
Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
James J. Feng*
Affiliation:
Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada Department of Mathematics, University of British Columbia, Vancouver, BC V6T 1Z2, Canada
*
Email address for correspondence: [email protected]

Abstract

Capillary instability of a Newtonian liquid torus suspended in an immiscible Newtonian medium is computed using a Cahn–Hilliard diffuse-interface model. The main differences between the torus and a straight thread are the presence of an axial curvature and an external flow field caused by the retraction of the torus. We show that the capillary wave initially grows linearly as on a straight thread. The axial curvature decreases the growth rate of the capillary waves while the external flow enhances it. Breakup depends on the competition of two time scales: one for torus retraction and the other for neck pinch-off. The outcome is determined by the initial amplitude of the disturbance, the thickness of the torus relative to its circumference, and the torus-to-medium viscosity ratio. The linearly dominant mode may not persist till nonlinear growth and breakup. The numerical results are generally consistent with experimental observations.

Type
Papers
Copyright
©2013 Cambridge University Press

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References

Bostwick, J. B. & Steen, P. H. 2010 Stability of constrained cylindrical interfaces and the torus lift of Plateau–Rayleigh. J. Fluid Mech. 647, 201219.Google Scholar
Cohen, I., Brenner, M. P., Eggers, J. & Nagel, S. R. 1999 Two fluid drop snap-off problem: experiments and theory. Phys. Rev. Lett. 83, 11471150.Google Scholar
Eggers, J. & Villermaux, E. 2008 Physics of liquid jets. Rep. Prog. Phys. 71, 036601.CrossRefGoogle Scholar
Gao, P. & Feng, J. J. 2011a A numerical investigation of the propulsion of water walkers. J. Fluid Mech. 668, 363383.Google Scholar
Gao, P. & Feng, J. J. 2011b Spreading and breakup of a compound drop on a partially wetting substrate. J. Fluid Mech. 682, 415433.CrossRefGoogle Scholar
Gomes, D. A. 2002 Stability of rotating liquid films. Q. J. Mech. Appl. Maths 55, 327343.Google Scholar
McGraw, J. D., Li, J., Tran, D. L., Shi, A.-C. & Dalnoki-Veress, K. 2010 Plateau–Rayleigh instability in a torus: formation and breakup of a polymer ring. Soft Matt. 6, 12581262.Google Scholar
Mehrabian, H. & Feng, J. J. 2011 Wicking flow through microchannels. Phys. Fluids 23, 122108.CrossRefGoogle Scholar
Mikami, T., Cox, R. G. & Mason, S. G. 1975 Breakup of extending liquid threads. Intl J. Multiphase Flow 2, 113138.CrossRefGoogle Scholar
Nguyen, T. D., Fuentes-Cabrera, M., Fowlkes, J. D., Diez, J. A., González, A. G., Kondic, L. & Rack, P. D. 2012 Competition between collapse and breakup in nanometre-sized thin rings using molecular dynamics and continuum modelling. Langmuir 28, 1396013967.Google Scholar
Pairam, E. & Fernández-Nieves, A. 2009 Generation and stability of toroidal droplets in a viscous liquid. Phys. Rev. Lett. 102, 234501.CrossRefGoogle Scholar
Pizzi, A. & Mittal, K. L. 2003 Handbook of Adhesive Technology. Marcel Dekker.Google Scholar
Rayleigh, Lord 1878 On the instability of jets. Proc. Lond. Math. Soc. 10, 413.Google Scholar
Sirignano, W. A. & Mehring, C. 2000 Review of theory of distortion and disintegration of liquid streams. Prog. Energy Combust. Sci. 26, 609655.CrossRefGoogle Scholar
Tjahjadi, M., Stone, H. A. & Ottino, J. M. 1992 Satellite and subsatellite formation in capillary breakup. J. Fluid Mech. 243, 297317.Google Scholar
Tomotika, S. 1935 On the instability of a cylindrical thread of a viscous liquid surrounded by another viscous fluid. Proc. R. Soc. Lond. A 150, 322337.Google Scholar
Tomotika, S. 1936 Breaking up of a drop of viscous liquid immersed in another viscous fluid which is extending at a uniform rate. Proc. R. Soc. Lond. A 153, 302318.Google Scholar
Wu, Y., Fowlkes, J. D., Rack, P. D., Diez, J. A. & Kondic, L. 2010 On the breakup of patterned nanoscale copper rings into droplets via pulsed-laser-induced dewetting: competing liquid-phase instability and transport mechanisms. Langmuir 26, 1197211979.CrossRefGoogle ScholarPubMed
Wu, Z.-N. 2003 Approximate critical Weber number for the breakup of an expanding torus. Acta Mech. 166, 231239.CrossRefGoogle Scholar
Yao, Z. & Bowick, M. 2011 The shrinking instability of toroidal liquid droplets in the Stokes flow regime. Eur. Phys. J. E 34, 16.Google Scholar
Yue, P. & Feng, J. J. 2010 Sharp interface limit of the Cahn–Hilliard model for moving contact lines. J. Fluid Mech. 645, 279294.Google Scholar
Yue, P. & Feng, J. J. 2011a Can diffuse-interface models quantitatively describe moving contact lines? Eur. Phys. J. – Spec. Top. 197, 3746.Google Scholar
Yue, P. & Feng, J. J. 2011b Wall energy relaxation in the Cahn–Hilliard model for moving contact lines. Phys. Fluids 23, 012106.Google Scholar
Yue, P., Zhou, C. & Feng, J. J. 2006a A computational study of the coalescence between a drop and an interface in Newtonian and viscoelastic fluids. Phys. Fluids 18, 102102.Google Scholar
Yue, P., Zhou, C., Feng, J. J., Ollivier-Gooch, C. F. & Hu, H. H. 2006b Phase-field simulations of interfacial dynamics in viscoelastic fluids using finite elements with adaptive meshing. J. Comput. Phys. 219, 4767.CrossRefGoogle Scholar
Zhou, C., Yue, P. & Feng, J. J. 2007 The rise of Newtonian drops in a nematic liquid crystal. J. Fluid Mech. 593, 385404.Google Scholar
Zhou, C., Yue, P., Feng, J. J., Ollivier-Gooch, C. F. & Hu, H. H. 2010 3D phase-field simulations of interfacial dynamics in Newtonian and viscoelastic fluids. J. Comput. Phys. 229, 498511.Google Scholar