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Topological transition and helicity conversion of vortex knots and links

Published online by Cambridge University Press:  16 June 2022

Weiyu Shen
Affiliation:
State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871, PR China
Jie Yao
Affiliation:
Department of Mechanical Engineering, Texas Tech University, Lubbock, TX 79409, USA
Fazle Hussain
Affiliation:
Department of Mechanical Engineering, Texas Tech University, Lubbock, TX 79409, USA
Yue Yang*
Affiliation:
State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871, PR China HEDPS-CAPT and BIC-ESAT, Peking University, Beijing 100871, PR China
*
Email address for correspondence: yyg@pku.edu.cn

Abstract

Topological transition and helicity conversion of vortex torus knots and links are studied using direct numerical simulations of the incompressible Navier–Stokes equations. We find three topological transitional routes (viz. merging, reconnection and transition to turbulence) in the evolution of vortex knots and links over a range of torus aspect ratios and winding numbers. The topological transition depends not only on the initial topology but also on the initial geometry of knots/links. For small torus aspect ratios, the initially knotted or linked vortex tube rapidly merges into a vortex ring with a complete helicity conversion from the writhe and link components to the twist. For large torus aspect ratios, the vortex knot or link is untied into upper and lower coiled loops via the first vortex reconnection, with a helicity fluctuation including loss of writhe and link, and generation of twist. Then, the relatively unstable lower loop can undergo a secondary reconnection to split into multiple small vortices with a similar helicity fluctuation. Surprisingly, for moderate torus aspect ratios, the incomplete reconnection of tangled vortex loops together with strong vortex interactions triggers transition to turbulence, in which the topological helicity decomposition fails due to the breakdown of vortex core lines.

Type
JFM Papers
Copyright
© The Author(s), 2022. Published by Cambridge University Press

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References

REFERENCES

Adams, C.C. 1994 The Knot Book. American Mathematical Society.Google Scholar
Aldinger, J., Klapper, I. & Tabor, M. 1995 Formulae for the calculation and estimation of writhe. J. Knot Theory Ramif. 4, 343372.CrossRefGoogle Scholar
Aref, H. & Zawadzki, I. 1991 Linking of vortex rings. Nature 354, 5053.CrossRefGoogle Scholar
Baggaley, A.W. 2012 The sensitivity of the vortex filament method to different reconnection models. J. Low Temp. Phys. 168, 1830.CrossRefGoogle Scholar
Barenghi, C.F. 2007 Knots and unknots in superfluid turbulence. Milan J. Maths 75, 177196.CrossRefGoogle Scholar
Barenghi, C.F., Hänninen, R. & Tsubota, M. 2006 Anomalous translational velocity of vortex ring with finite-amplitude Kelvin waves. Phys. Rev. E 74, 046303.CrossRefGoogle ScholarPubMed
Berger, M.A. & Field, G.B. 1984 The topological properties of magnetic helicity. J. Fluid Mech. 147, 133148.CrossRefGoogle Scholar
Betchov, R. 1965 On the curvature and torsion of an isolated vortex filament. J. Fluid Mech. 22, 471479.CrossRefGoogle Scholar
Brenner, M.P., Hormoz, S. & Pumir, A. 2016 Potential singularity mechanism for the Euler equations. Phys. Rev. Fluids 1, 084503.CrossRefGoogle Scholar
Brissaud, A., Frisch, U., Léorat, J., Lesieur, M. & Mazure, A. 1973 Helicity cascades in fully developed isotropic turbulence. Phys. Fluids 16, 13661367.CrossRefGoogle Scholar
Chui, A.Y.K. & Moffatt, H.K. 1995 The energy and helicity of knotted magnetic flux tubes. Proc. R. Soc. Lond. A 451, 609629.Google Scholar
Cirtain, J.W., et al. 2013 Energy release in the solar corona from spatially resolved magnetic braids. Nature 493, 501503.CrossRefGoogle ScholarPubMed
Dennis, M.R., King, R.P., Jack, B., O'Holleran, K. & Padgett, M.J. 2010 Isolated optical vortex knots. Nat. Phys. 6, 118121.CrossRefGoogle Scholar
Fuentes, O.V. 2010 Chaotic streamlines in the flow of knotted and unknotted vortices. Theor. Comput. Fluid Dyn. 24, 189193.CrossRefGoogle Scholar
Fuller, F.B. 1971 The writhing number of a space curve. Proc. Natl Acad. Sci. USA 68, 815819.CrossRefGoogle ScholarPubMed
Griffiths, R.W. & Hopfinger, E.J. 1987 Coalescing of geostrophic vortices. J. Fluid Mech. 178, 7397.CrossRefGoogle Scholar
Hama, F.R. 1962 Progressive deformation of a curved vortex filament by its own induction. Phys. Fluids 5, 11561162.CrossRefGoogle Scholar
Hänninen, R. & Baggaley, A.W. 2014 Vortex filament method as a tool for computational visualization of quantum turbulence. Proc. Natl Acad. Sci. USA 111, 46674674.CrossRefGoogle ScholarPubMed
Hao, J. & Yang, Y. 2021 Magnetic knot cascade via the stepwise reconnection of helical flux tubes. J. Fluid Mech. 912, A48.CrossRefGoogle Scholar
Hasimoto, H. 1972 A soliton on a vortex filament. J. Fluid Mech. 51, 477485.CrossRefGoogle Scholar
Hide, R. 1989 Superhelicity, helicity and potential vorticity. Geophys. Astrophys. Fluid Dyn. 48, 6979.CrossRefGoogle Scholar
Irvine, W.T.M. & Bouwmeester, D. 2008 Linked and knotted beams of light. Nat. Phys. 4, 716720.CrossRefGoogle Scholar
Keener, J.P. 1990 Knotted vortex filaments in an ideal fluid. J. Fluid Mech. 211, 629651.CrossRefGoogle Scholar
Kerr, R.M. 2018 a Enstrophy and circulation scaling for Navier–Stokes reconnection. J. Fluid Mech. 839, R2.CrossRefGoogle Scholar
Kerr, R.M. 2018 b Topology of interacting coiled vortex rings. J. Fluid Mech. 854, R2.CrossRefGoogle Scholar
Kerr, R.M. 2018 c Trefoil knot timescales for reconnection and helicity. Fluid Dyn. Res. 50, 011422.CrossRefGoogle Scholar
Kida, S. 1981 A vortex filament moving without change of form. J. Fluid Mech. 112, 397409.CrossRefGoogle Scholar
Kida, S. & Takaoka, M. 1987 Bridging in vortex reconnection. Phys. Fluids 30, 29112914.CrossRefGoogle Scholar
Kida, S. & Takaoka, M. 1988 Reconnection of vortex tubes. Fluid Dyn. Res. 3, 257261.CrossRefGoogle Scholar
Kida, S. & Takaoka, M. 1991 Breakdown of frozen motion of vorticity field and vorticity reconnection. J. Phys. Soc. Japan 60, 21842196.CrossRefGoogle Scholar
Kida, S. & Takaoka, M. 1994 Vortex reconnection. Annu. Rev. Fluid Mech. 26, 169177.CrossRefGoogle Scholar
Kida, S., Takaoka, M. & Hussain, F. 1991 Collision of two vortex rings. J. Fluid Mech. 230, 583646.CrossRefGoogle Scholar
Kimura, Y. & Moffatt, H.K. 2017 Scaling properties towards vortex reconnection under Biot–Savart evolution. Fluid Dyn. Res. 50, 011409.CrossRefGoogle Scholar
Kivotides, D. & Leonard, A. 2021 Helicity spectra and topological dynamics of vortex links at high Reynolds numbers. J. Fluid Mech. 911, A25.CrossRefGoogle Scholar
Kleckner, D. & Irvine, W.T.M. 2013 Creation and dynamics of knotted vortices. Nat. Phys. 9, 253258.CrossRefGoogle Scholar
Kleckner, D., Kauffman, L.H. & Irvine, W.T.M. 2016 How superfluid vortex knots untie. Nat. Phys. 12, 650655.CrossRefGoogle Scholar
Klotz, A.R., Soh, B.W. & Doyle, P.S. 2018 Motion of knots in DNA stretched by elongational fields. Phys. Rev. Lett. 120, 188003.CrossRefGoogle ScholarPubMed
Laing, C.E., Ricca, R.L. & Sumners, D.W. 2015 Conservation of writhe helicity under anti-parallel reconnection. Sci. Rep. 5, 16.CrossRefGoogle ScholarPubMed
Le Dizes, S. & Verga, A. 2002 Viscous interactions of two co-rotating vortices before merging. J. Fluid Mech. 467, 389410.CrossRefGoogle Scholar
Levy, Y., Degani, D. & Seginer, A. 1990 Graphical visualization of vortical flows by means of helicity. AIAA J. 28, 13471352.CrossRefGoogle Scholar
Liu, X., Ricca, R.L. & Li, X.-F. 2020 Minimal unlinking pathways as geodesics in knot polynomial space. Commun. Phys. 3, 136.CrossRefGoogle Scholar
Martinez, A., Ravnik, M., Lucero, B., Visvanathan, R., Žumer, S. & Smalyukh, I.I. 2014 Mutually tangled colloidal knots and induced defect loops in nematic fields. Nat. Mater. 13, 258263.CrossRefGoogle ScholarPubMed
Maxworthy, T. 1977 Some experimental studies of vortex rings. J. Fluid Mech. 81, 465495.CrossRefGoogle Scholar
Melander, M.V. & Hussain, F. 1988 Cut-and-connect of two antiparallel vortex tubes. In Studying Turbulence Using Numerical Simulation Databases, vol. 2, pp. 257–286. Center for Turbulence Research.Google Scholar
Melander, M.V., Zabusky, N.J. & McWilliams, J.C. 1988 Symmetric vortex merger in two dimensions: causes and conditions. J. Fluid Mech. 195, 303340.CrossRefGoogle Scholar
Milnor, J. & Weaver, D.W. 1997 Topology from the Differentiable Viewpoint. Princeton University Press.Google Scholar
Moffatt, H.K. 1969 The degree of knottedness of tangled vortex lines. J. Fluid Mech. 35, 117129.CrossRefGoogle Scholar
Moffatt, H.K. 2021 Some topological aspects of fluid dynamics. J. Fluid Mech. 914, 4348.CrossRefGoogle Scholar
Moffatt, H.K., Kida, S. & Ohkitani, K. 1994 Stretched vortices–the sinews of turbulence; large-Reynolds-number asymptotics. J. Fluid Mech. 259, 241264.CrossRefGoogle Scholar
Moffatt, H.K. & Ricca, R.L. 1992 Helicity and the Călugăreanu invariant. Proc. R. Soc. Lond. A 439, 411429.Google Scholar
Moffatt, H.K. & Tsinober, A. 1992 Helicity in laminar and turbulent flow. Annu. Rev. Fluid Mech. 24, 281312.CrossRefGoogle Scholar
Moreau, J.J. 1961 Constantes d'un îlot tourbillonnaire en fluide parfait barotrope. C. R. Acad. Sci. Paris 252, 28102812.Google Scholar
Oberti, C. & Ricca, R.L. 2016 On torus knots and unknots. J. Knot Theory Ramif. 25, 1650036.CrossRefGoogle Scholar
Oberti, C. & Ricca, R.L. 2019 Influence of winding number on vortex knots dynamics. Sci. Rep. 9, 17284.CrossRefGoogle ScholarPubMed
Pope, S.B. 2000 Turbulent Flows. Cambridge University Press.CrossRefGoogle Scholar
Proment, D., Onorato, M. & Barenghi, C.F. 2012 Vortex knots in a Bose–Einstein condensate. Phys. Rev. E 85, 036306.CrossRefGoogle Scholar
Ricca, R.L. & Berger, M.A. 1996 Topological ideas and fluid mechanics. Phys. Today 49, 2834.CrossRefGoogle Scholar
Ricca, R.L., Samuels, D.C. & Barenghi, C.F. 1999 Evolution of vortex knots. J. Fluid Mech. 391, 2944.CrossRefGoogle Scholar
Scheeler, M.W., Kleckner, D., Proment, D., Kindlmann, G.L. & Irvine, W.T.M. 2014 Helicity conservation by flow across scales in reconnecting vortex links and knots. Proc. Natl Acad. Sci. USA 111, 1535015355.CrossRefGoogle ScholarPubMed
Scheeler, M.W., van Rees, W.M., Kedia, H., Kleckner, D. & Irvine, W.T.M. 2017 Complete measurement of helicity and its dynamics in vortex tubes. Science 357, 487491.CrossRefGoogle ScholarPubMed
Schwarz, K.W. 1985 Three-dimensional vortex dynamics in superfluid He 4: Line-line and line-boundary interactions. Phys. Rev. B 31, 5782.CrossRefGoogle Scholar
Takaki, R. & Hussain, F. 1988 Singular interaction of vortex filaments. Fluid Dyn. Res. 3, 251.CrossRefGoogle Scholar
Thomson, W. 1878 Vortex statics. Proc. R. Soc. Edin. 9, 5973.CrossRefGoogle Scholar
Tkalec, U., Ravnik, M., Čopar, S., Žumer, S. & Muševič, I. 2011 Reconfigurable knots and links in chiral nematic colloids. Science 333, 6265.CrossRefGoogle ScholarPubMed
Wasserman, S.A. & Cozzarelli, N.R. 1986 Biochemical topology: applications to DNA recombination and replication. Science 232, 951960.CrossRefGoogle ScholarPubMed
Xiong, S. & Yang, Y. 2019 a Construction of knotted vortex tubes with the writhe-dependent helicity. Phys. Fluids 31, 047101.CrossRefGoogle Scholar
Xiong, S. & Yang, Y. 2019 b Identifying the tangle of vortex tubes in homogeneous isotropic turbulence. J. Fluid Mech. 874, 952978.CrossRefGoogle Scholar
Xiong, S. & Yang, Y. 2020 Effects of twist on the evolution of knotted magnetic flux tubes. J. Fluid Mech. 895, A28.CrossRefGoogle Scholar
Yang, Y., Pullin, D.I. & Bermejo-Moreno, I. 2010 Multi-scale geometric analysis of Lagrangian structures in isotropic turbulence. J. Fluid Mech. 654, 233270.CrossRefGoogle Scholar
Yao, J. & Hussain, F. 2020 a A physical model of turbulence cascade via vortex reconnection sequence and avalanche. J. Fluid Mech. 883, A53.CrossRefGoogle Scholar
Yao, J. & Hussain, F. 2020 b On singularity formation via viscous vortex reconnection. J. Fluid Mech. 888, R2.CrossRefGoogle Scholar
Yao, J. & Hussain, F. 2022 Vortex reconnection and turbulence cascade. Annu. Rev. Fluid Mech. 54, 317347.CrossRefGoogle Scholar
Yao, J., Yang, Y. & Hussain, F. 2021 Dynamics of a trefoil knotted vortex. J. Fluid Mech. 923, A19.CrossRefGoogle Scholar
Zhao, X. & Scalo, C. 2021 Helicity dynamics in reconnection events of topologically complex vortex flows. J. Fluid Mech. 920, A30.CrossRefGoogle Scholar
Zhao, X., Yu, Z., Chapelier, J.-B. & Scalo, C. 2021 Direct numerical and large-eddy simulation of trefoil knotted vortices. J. Fluid Mech. 910, A31.CrossRefGoogle Scholar
Zheng, T., You, J. & Yang, Y. 2017 Principal curvatures and area ratio of propagating surfaces in isotropic turbulence. Phys. Rev. Fluids 2, 103201.CrossRefGoogle Scholar
Zuccher, S. & Ricca, R.L. 2017 Relaxation of twist helicity in the cascade process of linked quantum vortices. Phys. Rev. E 95, 053109.CrossRefGoogle ScholarPubMed