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An experimental study of a turbulent vortex ring

Published online by Cambridge University Press:  26 April 2006

Ari Glezer
Affiliation:
Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ 85721, USA
Donald Coles
Affiliation:
California Institute of Technology, Pasadena, CA 91125, USA

Abstract

A turbulent vortex ring having a relatively thin core is formed in water by a momentary jet discharge from an orifice in a submerged plate. The necessary impulse is provided by a pressurized reservoir and is controlled by a fast programmable solenoid valve. The main aim of the research is to verify the similarity properties of the mean flow, as defined by ensemble averaging, and to find the distribution of mean vorticity, turbulent energy, and other quantities in the appropriate non-steady similarity coordinates. The velocity field of the vortex is measured for numerous realizations with the aid of a two-channel tracking laser-Doppler velocimeter. The problem of dispersion in the trajectories of the individual rings is overcome by development of a signature-recognition technique in two variables. It is found that the turbulence intensity is largest near the vortex core and that at least the radial component is not negligible in the near wake. The slow growth of the ring structure is controlled by a slight excess of entrainment over de-entrainment. An important inference is that the growth process and the process of turbulence production probably involve secondary vortices wrapped around the core in azimuthal planes.

Type
Research Article
Copyright
© 1990 Cambridge University Press

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References

Akhmetov, D. G. & Kisarov, O. P. 1966 Hydrodynamic structure of a vortex ring. J. Appl. Mech. Tech. Phys. 7, 8790.Google Scholar
Cantwell, B., Coles, D. & Dimotakis, P. 1978 Structure and entrainment in the plane of symmetry of a turbulent spot. J. Fluid Mech. 87, 641672.Google Scholar
Didden, N. 1977 Untersuchung laminarer, instabiler Ringwirbel mittels Laser-Doppler-Anemometrie. Dissertation, University of Göttingen; also Mitt. MPI und AVA, Göttingen, Nr. 64.
Didden, N. 1979 On the formation of vortex rings: rolling-up and production of circulation. Z. Angew. Math. Phys. 30, 101116.Google Scholar
Glezer, A. 1981 An experimental study of a turbulent vortex ring. Ph.D. thesis, California Institute of Technology.
Glezer, A. 1988 On the formation of vortex rings. Phys. Fluids 31, 35323542.Google Scholar
Glezer, A. & Coles, D. 1982 A two-grating method for combined beam splitting and frequency shifting in a two-component laser-Doppler velocimeter. Phys. Fluids 25, 21422146.Google Scholar
Grigg, H. R. & Stewart, R. W. 1963 Turbulent diffusion in a stratified fluid. J. Fluid Mech. 15, 174186.Google Scholar
Johnson, G. M. 1970 Researches on the propagation and decay of vortex rings. Rep. ARL 70–0093. Aerosp. Res. Labs., Wright-Patterson AFB.Google Scholar
Johnson, G. M. 1971 An empirical model of turbulent vortex rings. AIAA J. 9, 763764.Google Scholar
Kovasznay, L. S. G., Fujita, H. & Lee, R. L. 1973 Unsteady turbulent puffs. Adv. Geophys. 18B, 253263.Google Scholar
Krutzch, C. H. 1939 Über eine experimentele beobachtete Erscheinung an Wirbelringen bei ihrer translatorischen Bewegung in Wirklichen Flüssigkeiten. Ann. Phys. 35, 497523.Google Scholar
Maxworthy, T. 1974 Turbulent vortex rings. J. Fluid Mech. 64, 227239.Google Scholar
Maxworthy, T. 1977 Some experimental studies of vortex rings. J. Fluid Mech. 81, 465495.Google Scholar
Northrup, E. F. 1912 A photographic study of vortex rings in liquids. Nature 88, 463468.Google Scholar
Oshima, K., Kovasznay, L. S. G. & Oshima, Y. 1977 Sound emission from burning puff. In Proceedings, Symposium on Structure and Mechanisms of Turbulence, Vol. II (ed. H. Fielder). Lecture Notes in Physics, vol. 76, pp. 219230. Springer.
Perry, A. E. & Fairlie, B. D. 1974 Critical points in flow patterns. Adv. Geophys. 18B, 299315.Google Scholar
Perry, A. E. & Tan, D. K. M. 1984 Simple three-dimensional vortex motions in coflowing jets and wakes. J. Fluid Mech. 141, 197231.Google Scholar
Ralston, A. & Wilf, H. S. 1960 Mathematical Methods for Digital Computers. John Wiley & Sons.
Richards, J. M. 1965 Puff motions in unstratified surroundings. J. Fluid Mech. 21, 97106.Google Scholar
Saffman, P. G. 1970 The velocity of viscous vortex rings. Stud. Appl. Maths 49, 371380.Google Scholar
Sallet, D. W. & Widmayer, R. S. 1974 An experimental investigation of laminar and turbulent vortex rings in air. Z. Flugwiss. 22, 207215.Google Scholar
Schneider, P. 1980 Sekundärwirbelbildung bei Ringwirbeln und in Freistrahlen. Z. Flugwiss. Weltraumforsch. 4, 307318.Google Scholar
Sullivan, J. P., Widnall, S. E. & Ezekiel, S. 1973 Study of a vortex ring using laser Doppler velocimeter. AIAA J. 11, 13841389.Google Scholar
Turner, J. S. 1957 Buoyant vortex rings. Proc. R. Soc. Lond. A 239, 6175.Google Scholar
Turner, J. S. 1964 The flow into an expanding spherical vortex. J. Fluid Mech. 18, 195208.Google Scholar
Widnall, S. E., Bliss, D. B. & Tsai, C.-Y. 1974 The instability of short waves on a vortex ring. J. Fluid Mech. 66, 3547.Google Scholar
Woodward, B. 1959 The motion in and around isolated thermals. Q. J. R. Met. Soc. 85, 144151.Google Scholar