Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-19T15:14:49.585Z Has data issue: false hasContentIssue false

Wave motions on vortex cores

Published online by Cambridge University Press:  20 April 2006

T. Maxworthy
Affiliation:
Institut de Mécanique (Laboratoire Associé au CNRS), Université de Grenoble, B.P. n° 68, 38402 St Martin d'Hères Cedex, France Permanent address: Departments of Mechanical and Aerospace Engineering, University of Southern California, Los Angeles, CA 90039-1453, U.S.A.
E. J. Hopfinger
Affiliation:
Institut de Mécanique (Laboratoire Associé au CNRS), Université de Grenoble, B.P. n° 68, 38402 St Martin d'Hères Cedex, France
L. G. Redekopp
Affiliation:
Department of Aerospace Engineering, University of Southern California, Los Angeles, CA 90089-1454, U.S.A.

Abstract

The observation of large-amplitude ‘kink’ waves on the vortex cores produced by an oscillating grid in a rotating fluid (Hopfinger, Browand & Gagne 1982) has motivated the study of such waves under more controlled circumstances. We have experimentally observed the properties of helical waves, rotating, plane standing waves and evolving, isolated kink-waves. Their characteristics have been related to theories based on the localized induction equation of Arms & Hama (1965), the ‘cut-off’ theory of Crow (1970) as extended by Moore & Saffman (1972), and an extension of Pocklington's (1895) dispersion relationship for ‘hollow-core’ vortices. It is shown that the latter dispersion relation and the Moore & Saffman theory are good approximations to our experimental results. Using these, we present new results on solitary kink-wave properties of concentrated vortex flows, and in particular show that envelope solitons are possible only for a restricted range of carrier wavenumbers. A second class of waves was also observed: the axisymmetric solitary waves of Benjamin (1967). These were found to become unstable to spiral disturbances when their amplitude exceeded a certain magnitude, as has been found in the study of the related vortex-breakdown phenomenon. All of these observations are used to interpret the experiments presented by HBG and to discuss qualitatively the dynamics of rotating turbulence. In the Appendix we propose a possible mechanism by which concentrated vortices can be formed in a rotating turbulent fluid.

Type
Research Article
Copyright
© 1985 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

Arms, R. J. & Hama, F. R. 1965 Localized-induction concept on a curved vortex and motion of an elliptic vortex ring. Phys. Fluids 8, 553559.Google Scholar
Batchelor G. B.1967 An Introduction to Fluid Dynamics. Cambridge University Press.
Benjamin T. B.1962 Theory of the vortex breakdown phenomenon. J. Fluid Mech. 14, 593629.Google Scholar
Benjamin T. B.1967a Some developments in the theory of vortex breakdown. J. Fluid Mech. 28, 6584.Google Scholar
Benjamin T. B.1967b Internal waves of permanent form in fluids of great depth. J. Fluid Mech. 29, 559592.Google Scholar
Betchov R.1965 On the curvature and torsion of an isolated vortex filament. J. Fluid Mech. 22, 471479.Google Scholar
Browand, F. K. & Hopfinger E. J.1981 Spread of turbulence into stratified fluid. APS Meeting, paper D.E. 1.Google Scholar
Browand, F. K. & Hopfinger E. J.1983 The inhibition of vertical turbulent scale by stable stratification. In IMA Conf. Proc., Cambridge.
Burgers J. M.1948 A mathematical model illustrating the theory of turbulence. Adv. Appl. Mech. 1, 171199.Google Scholar
Crow S. H.1970 Stability theory for a pair of trailing vortices. AIAA J. 8, 1731.Google Scholar
Davis, R. E. & Acrivos A.1967 Solitary internal waves in deep water. J. Fluid Mech. 29, 593607.Google Scholar
Dickinson, S. C. & Long, R. R. 1983 Oscillating grid turbulence including effects of rotation. J. Fluid Mech. 126, 315333.Google Scholar
Escudier M. P., Bornstein, J. & Maxworthy T.1982 The dynamics of confined vortices Proc. R. Soc. Lond. A 382, 335360.Google Scholar
Escudier M. P., Bornstein, J. & Zehnder N.1980 Observations and LDA measurements of confined vortex flow. J. Fluid Mech. 98, 4963.Google Scholar
Garg, A. K. & Leibovich, S. 1979 Spectral characteristics of vortex breakdown flow fields. Phys. Fluids 22, 20532070.Google Scholar
Gluck, D. F. 1972 Vortex formation, free surface deformation and flow field structure in the discharge of liquid from a rotating tank. Ph.D. dissertation, University of Southern California, Los Angeles; also North American Rockwell Corp. Rep. 5072-SA-0108.
Granger R.1968 Speed of a surge in a bathtub vortex. J. Fluid Mech. 34, 651656.Google Scholar
Harvey J. K.1962 Some observations of the vortex breakdown phenomenon. J. Fluid Mech. 14, 585592.Google Scholar
Hasimoto H.1972 A soliton on a vortex filament. J. Fluid Mech. 51, 47785.Google Scholar
Hopfinger, E. J. & Browand F. K.1982 Vortex solitary waves in a rotating, turbulent flow. Nature 295, 393396.Google Scholar
Hopfinger E. J., Browand, F. K. & Gagne Y.1982 Turbulence and waves in a rotating tank. J. Fluid Mech. 125, 505534.Google Scholar
Hopfinger, E. J. & Toly J. A.1976 Spatially decaying turbulence and its relation to mixing across density interfaces. J. Fluid Mech. 78, 155176.Google Scholar
Ivey, G. N. & Corcos G. M.1982 Boundary mixing in a stratified fluid. J. Fluid Mech. 121, 126.Google Scholar
Kida S.1981 A vortex filament moving without change of form. J. Fluid Mech. 112, 397409.Google Scholar
Lamb G. L.1980 Elements of Soliton Theory. Wiley-Interscience.
Lambourne, N. C. & Byer D. W.1961 The bursting of leading edge vortices - some observations and discussion of the phenomenon. Aero. Res. Counc. R & M 3282.Google Scholar
Leibovich S.1970 Weakly non-linear waves in rotating fluids. J. Fluid Mech. 42, 803822.Google Scholar
Leibovich, S. & Ma H. Y.1983 Soliton propagation on vortex cores and the Hasimoto soliton. Phys. Fluids 26, 31733179.Google Scholar
Lessen M., Singh, P. J. & Paillet F.1974 The stability of a trailing line vortex. Part 1. Inviscid theory. J. Fluid Mech. 63, 753763.Google Scholar
Levy, H. & Forsdyke A. G.1928 The steady motion and stability of a helical vortex Proc. R. Soc. Lond. A 120, 670690.Google Scholar
Maxworthy T.1970 The flow created by a sphere moving along the axis of a rotating, slightly viscous fluid. J. Fluid Mech. 40, 45379.Google Scholar
Maxworthy T.1972 On the structure of concentrated, columnar vortices. Astro. Acta 17, 363374.Google Scholar
Maxworthy T.1980 On the formation of nonlinear internal waves from the gravitational collapse of mixed regions in two and three dimensions. J. Fluid Mech. 96, 4764.Google Scholar
Maxworthy T.1981 The laboratory modelling of atmospheric vortices: a critical review. In Intense Atmospheric Vortices (ed. L. Bengtsson & J. Lighthill), pp. 229246. Springer.
Maxworthy T., Mory, M. & Hopfinger E. J.1983 Waves on vortex cores and their relation to vortex breakdown. Proc. AGARD Conf. on Aerodynamics of Vertical Type Flows in Three Dimensions; AGARD CPP-342, paper 29.
Moore, D. N. & Saffman P. G.1972 The notion of a vortex filament with axial flow Phil. Trans. R. Soc. Lond. A 272, 403429.Google Scholar
Pocklington H. C.1895 The complete system of the periods of a hollow vortex ring Phil. Trans. R. Soc. Lond. A 186. 603.Google Scholar
Pritchard W. G.1970 Solitary waves in rotating fluids. J. Fluid Mech. 42. 6183.Google Scholar
Sallet, R. S. & Widmeyer, D. W. 1974 An experimental investigation of laminar and turbulent vortex rings in air. Z. Flugwiss. 22, 207215.Google Scholar
Sarpkaya T.1971 On stationary and travelling vortex breakdown. J. Fluid Mech. 45, 545559.Google Scholar
Squire H. B.1962 Analysis of the vortex breakdown phenomenon. Part I. Miszellanen der angew. Mech. 306312, Akademie Berlin.
Thomson W.1880 On the vibrations of a columnar vortex Phil. Mag. (5) 10, 155.Google Scholar
Thorpe S. A.1982 On the layers produced by rapidly oscillating a vertical grid in a uniformly stratified fluid. J. Fluid Mech. 124, 391409.Google Scholar
Yuen, H. C. & Lake B. M.1975 Non linear deep water waves: theory and experiment. Phys. Fluids 18, 956960.Google Scholar