Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-12-01T06:45:54.441Z Has data issue: false hasContentIssue false

Axisymmetric contour dynamics for buoyant vortex rings

Published online by Cambridge University Press:  29 January 2020

Ching Chang*
Affiliation:
Department of Mechanical and Aerospace Engineering, Jacobs School of Engineering, UCSD, 9500 Gilman Drive, La Jolla, CA 92093-0411, USA
Stefan G. Llewellyn Smith
Affiliation:
Department of Mechanical and Aerospace Engineering, Jacobs School of Engineering, UCSD, 9500 Gilman Drive, La Jolla, CA 92093-0411, USA Scripps Institution of Oceanography, UCSD, 9500 Gilman Drive, La Jolla, CA 92093-0213, USA
*
Email address for correspondence: [email protected]

Abstract

The present work uses a reduced-order model to study the motion of a buoyant vortex ring with non-negligible core size. Buoyancy is considered in both non-Boussinesq and Boussinesq situations using an axisymmetric contour dynamics formulation. The density of the vortex ring differs from that of the ambient fluid, and both densities are constant and conserved. The motion of the ring is calculated by following the boundary of the vortex core, which is also the interface between the two densities. The velocity of the contour comes from a combination of a specific continuous vorticity distribution within its core and a vortex sheet on the core boundary. An evolution equation for the vortex sheet is derived from the Euler equation, which simplifies considerably in the Boussinesq limit. Numerical solutions for the coupled integro-differential equations are obtained. The dynamics of the vortex sheet and the formation of two possible singularities, including singularities in the curvature and the shock-like profile of the vortex sheet strength, are discussed. Three dimensionless groups, the Atwood, Froude and Weber numbers, are introduced to measure the importance of physical effects acting on the motion of a buoyant vortex ring.

Type
JFM Papers
Copyright
© The Author(s), 2020. Published by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Baker, G. R., Caflisch, R. & Siegel, M. 1993 Singularity formation during Rayleigh–Taylor instability. J. Fluid Mech. 252, 5178.CrossRefGoogle Scholar
Baker, G. R., Meiron, D. I. & Orszag, S. A. 1982 Generalized vortex methods for free-surface flow problems. J. Fluid Mech. 123, 477501.CrossRefGoogle Scholar
Baker, G. R. & Moore, D. W. 1989 The rise and distortion of a two-dimensional gas bubble in an inviscid liquid. Phys. Fluids A 1, 14511459.CrossRefGoogle Scholar
Baker, G. R. & Nachbin, A. 1998 Stable methods for vortex sheet motion in the presence of surface tension. SIAM J. Sci. Comput. 19, 17371766.CrossRefGoogle Scholar
Baker, G. R. & Xie, C. 2011 Singularities in the complex physical plane for deep water waves. J. Fluid Mech. 685, 83116.CrossRefGoogle Scholar
Blyth, M., Rodriguez-Rodriguez, J. & Salman, H. 2014 Buoyant Norbury’s vortex rings. In 67th Annual Meeting of the APS Division of Fluid Dynamics, vol. 59. American Physical Society.Google Scholar
Chang, C. & Llewellyn Smith, S. G. 2018 The motion of a buoyant vortex filament. J. Fluid Mech. 857, R1.CrossRefGoogle Scholar
Chen, L., Garimella, S. V., Reizes, J. A. & Leonardi, E. 1999 The development of a bubble rising in a viscous liquid. J. Fluid Mech. 387, 6196.CrossRefGoogle Scholar
Cheng, M., Lou, J. & Lim, T. T. 2013 Motion of a bubble ring in a viscous fluid. Phys. Fluids 25, 067104.CrossRefGoogle Scholar
Cowley, S. J., Baker, G. R. & Tanveer, S. 1999 On the formation of Moore curvature singularities in vortex sheets. J. Fluid Mech. 378, 233267.CrossRefGoogle Scholar
Dritschel, D. G. 1989 Contour dynamics and contour surgery: numerical algorithms for extended, high-resolution modelling of vortex dynamics in two-dimensional, inviscid, incompressible flows. Comput. Phys. Rep. 10, 77146.CrossRefGoogle Scholar
Fraenkel, L. E. 1972 Examples of steady vortex rings of small cross-section in an ideal fluid. J. Fluid Mech. 51, 119135.CrossRefGoogle Scholar
Hattori, Y. & Moffatt, H. K. 2006 Evolution of toroidal magnetic eddies in an ideal fluid. J. Fluid Mech. 558, 253279.CrossRefGoogle Scholar
Hicks, W. M. 1884 On the steady motion and small vibrations of a hollow vortex. Phil. Trans. R. Soc. Lond. A 175, 161195.Google Scholar
Hou, T. Y., Lowengrub, J. S. & Shelley, M. J. 1994 Removing the stiffness from interfacial flows with surface tension. J. Comput. Phys. 114, 312338.CrossRefGoogle Scholar
Iserles, A. 2009 A First Course in the Numerical Analysis of Differential Equations. Cambridge University Press.Google Scholar
Kelvin, Lord 1867 The translatory velocity of a circular vortex ring. Phil. Mag. 33, 511512.Google Scholar
Krasny, R. 1986a Desingularization of periodic vortex sheet roll-up. J. Comput. Phys. 65, 292313.CrossRefGoogle Scholar
Krasny, R. 1986b A study of singularity formation in a vortex sheet by the point-vortex approximation. J. Fluid Mech. 167, 6593.CrossRefGoogle Scholar
Llewellyn Smith, S. G., Chang, C., Chu, T., Blyth, M., Hattori, Y. & Salman, H. 2018 Generalized contour dynamics: a review. Regular Chaotic Dyn. 23, 507518.CrossRefGoogle Scholar
Llewellyn Smith, S. G. & Hattori, Y. 2012 Axisymmetric magnetic vortices with swirl. Commun. Nonlinear Sci. Numer. Simul. 17, 21012107.CrossRefGoogle Scholar
Lundgren, T. S. & Mansour, N. N. 1991 Vortex ring bubbles. J. Fluid Mech. 224, 177196.CrossRefGoogle Scholar
Marten, K., Shariff, K., Psarakos, S. & White, D. J. 1996 Ring bubbles of dolphins. Sci. Am. 275, 8287.CrossRefGoogle ScholarPubMed
Meiron, D. I., Baker, G. R. & Orszag, S. A. 1982 Analytic structure of vortex sheet dynamics. Part 1. Kelvin–Helmholtz instability. J. Fluid Mech. 114, 283298.CrossRefGoogle Scholar
Moore, D. W. 1979 The spontaneous appearance of a singularity in the shape of an evolving vortex sheet. Proc. R. Soc. Lond. A 365, 105119.CrossRefGoogle Scholar
Nitsche, M. 2001 Singularity formation in a cylindrical and a spherical vortex sheet. J. Comput. Phys. 173, 208230.CrossRefGoogle Scholar
Nitsche, M. & Krasny, R. 1994 A numerical study of vortex ring formation at the edge of a circular tube. J. Fluid Mech. 276, 139161.CrossRefGoogle Scholar
Norbury, J. 1972 A steady vortex ring close to Hill’s spherical vortex. Proc. Camb. Phil. Soc. 72, 253284.CrossRefGoogle Scholar
Norbury, J. 1973 A family of steady vortex rings. J. Fluid Mech. 57, 417431.CrossRefGoogle Scholar
Pedley, T. J. 1968 The toroidal bubble. J. Fluid Mech. 32, 97112.CrossRefGoogle Scholar
Pozrikidis, C. 1986 The nonlinear instability of Hill’s vortex. J. Fluid Mech. 168, 337367.CrossRefGoogle Scholar
Pullin, D. I. 1992 Contour dynamics methods. Annu. Rev. Fluid Mech. 24, 89115.CrossRefGoogle Scholar
Riley, N. 1998 The fascination of vortex rings. Appl. Sci. Res. 59, 169189.Google Scholar
Saffman, P. G. 1992 Vortex Dynamics. Cambridge University Press.Google Scholar
Shariff, K. & Leonard, A. 1992 Vortex rings. Annu. Rev. Fluid Mech. 24, 235279.CrossRefGoogle Scholar
Shariff, K., Leonard, A. & Ferziger, J.1989 Dynamics of a class of vortex rings. Tech. Rep. 102257. NASA Tech. Rep.Google Scholar
Shariff, K., Leonard, A. & Ferziger, J. 2008 A contour dynamics algorithm for axisymmetric flow. J. Comput. Phys. 227, 90449062.CrossRefGoogle Scholar
Shin, S., Sohn, S.-I. & Hwang, W. 2014 Simple and efficient numerical methods for vortex sheet motion with surface tension. Intl J. Numer. Meth. Fluids 74, 422438.CrossRefGoogle Scholar
Shin, S., Sohn, S.-I. & Hwang, W. 2018 Vortex simulations of the Kelvin–Helmholtz instability with surface tension in density-stratified flows. Eur. J. Mech. (B/Fluids) 67, 168177.CrossRefGoogle Scholar
Sohn, S.-I. 2015 Stability and capillary dynamics of circular vortex sheets. Theor. Comput. Fluid Dyn. 29, 291310.CrossRefGoogle Scholar
Sohn, S.-I. & Hwang, W. 2005 Numerical simulations of vortex sheet evolution in stratified shear flow. J. Phys. Soc. Japan 74, 14721478.CrossRefGoogle Scholar
Stock, M. J., Dahm, W. J. A. & Tryggvason, G. 2008 Impact of a vortex ring on a density interface using a regularized inviscid vortex sheet method. J. Comput. Phys. 227, 90219043.CrossRefGoogle Scholar
Trefethen, L. N. & Weideman, J. A. C. 2014 The exponentially convergent trapezoidal rule. SIAM Rev. 56, 385458.CrossRefGoogle Scholar
Tryggvason, G. 1988 Numerical simulations of the Rayleigh–Taylor instability. J. Comput. Phys. 75, 253282.CrossRefGoogle Scholar
Turner, J. S. 1957 Buoyant vortex rings. Proc. R. Soc. Lond. A 239, 6175.Google Scholar
Vasel-Be-Hagh, A. R., Carriveau, R. & Ting, D. S.-K. 2015a A balloon bursting underwater. J. Fluid Mech. 769, 522540.CrossRefGoogle Scholar
Vasel-Be-Hagh, A. R., Carriveau, R., Ting, D. S.-K. & Turner, J. S. 2015b Drag of buoyant vortex rings. Phys. Rev. A 92, 043024.Google Scholar
Velasco Fuentes, O. 2014 Early observations and experiments on ring vortices. Eur. J. Mech. (B/Fluids) 43, 166171.CrossRefGoogle Scholar
Zabusky, N. J., Hughes, M. H. & Roberts, K. V. 1979 Contour dynamics for the Euler equations in two dimensions. J. Comput. Phys. 30, 96106.CrossRefGoogle Scholar