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Mechanisms of decay of laminar and turbulent vortices

Published online by Cambridge University Press:  19 April 2006

Mahinder S. Uberoi
Mahinder S. Uberoi
Affiliation:
Department of Aerospace Engineering Sciences, University of Colorado, Boulder
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Abstract

The dynamics of an infinitely long one-dimensional vortex and a swirl are compared with the dynamics of a semi-infinitely long trailing vortex and trailing swirl. With increasing distance, the change in the axial velocity difference between the core of the trailing vortex and the surrounding region causes radial convection and some associated axial convection of angular momentum. In laminar or turbulent trailing vortices, we show that under most conditions of interest this is the dominant mechanism for the decrease in the velocities of swirl in the core and corresponding growth of the core. On the basis of theoretical considerations and experimental observations, we show that the axial velocity difference between the core of the trailing vortex and the surrounding region is necessary for the sustenance of turbulence in the vortex core. A theory of the turbulent trailing vortex is developed on the basis of these mechanisms and the results are compared with our experimental observations.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 90 , Issue 2 , 29 January 1979 , pp. 241 - 255
Copyright
© 1979 Cambridge University Press

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References

Batchelor, G. K. 1964 Axial flow in trailing line vortices. J. Fluid Mech. 20, 645.Google Scholar
Chow, C. Y. & Uberoi, M. S. 1972 Stability of an electric discharge surrounded by a free vortex. Phys. Fluids 15, 2187.Google Scholar
Chandrasekhar, S. 1961 Hydrodynamic and Hydromagnetic Stability, p. 277. Oxford University Press.
Govindaraju, S. P. & Saffman, P. G. 1971 Flow in a turbulent trailing vortex. Phys. Fluids 14, 2074.Google Scholar
Herron, J. H. 1974 Comments on a ‘Note on the flow in a trailing vortex’. J. Engng Math. 8, 339.Google Scholar
Hoffman, E. R. & Joubert, P. N. 1963 Turbulent line vortices. J. Fluid Mech. 16, 395.Google Scholar
McCormick, B. W., Tangler, J. L. & Scherriel, H. E. 1968 Structure of trailing vortices. J. Aircraft 5, 260.Google Scholar
Macagno, M. & Macagno, E. 1975 Nonlinear behaviour of line vortices. Phys. Fluids 18, 1595.Google Scholar
Moore, D. W. & Saffman, P. G. 1973 Axial flow in laminar trailing vortices. Proc. Roy. Soc. A 333, 491.Google Scholar
Narain, J. P. & Uberoi, M. S. 1973 Nonlinear stability of trailing line vortices enclosing a central jet of light or dense fluid. Phys. Fluids 16, 1406.Google Scholar
Owen, P. R. 1970 The decay of a turbulent trailing vortex. Aero. Quart. 19, 69.Google Scholar
Rayleigh, Lord 1916 On the dynamics of revolving fluids. Proc. Roy. Soc. A 93, 148.Google Scholar
Rose, R. & Dee, F. W. 1963 Aircraft vortex wakes and their effects on aircraft. R.A.E. Tech. Note Aero 2934.Google Scholar
Singh, P. I. 1974 The structure and stability of a vortex. Ph.D. thesis, University of Colorado, Boulder.
Singh, P. I. & Uberoi, M. S. 1976 Experiments on vortex stability. Phys. Fluids 19, 1858.Google Scholar
Squire, H. B. 1965 The growth of a vortex in a turbulent flow. Aero. Quart. 16, 302.Google Scholar
Tam, K. K. 1973 A note on the flow in a trailing vortex. J. Engng Math. 7, 1.Google Scholar
Uberoi, M. S. 1974 Structure and decay of wing tip vortices. Bull. Am. Phys. Soc. 19, 1147.Google Scholar
Uberoi, M. S. 1977a Structure of a turbulent swirl. Phys. Fluids 20, 719.Google Scholar
Uberoi, M. S. 1977b The proper equation for the angular momentum of trailing vortices. Phys. Fluids 20, 1785.Google Scholar
Uberoi, M. S. 1977c Theory of turbulent line vortex decay. Bull. Am. Phys. Soc. 22, 1278.Google Scholar
Uberoi, M. S. 1978 Axial flow in line vortices. Bull. Am. Phys. Soc. 23, 524.Google Scholar
Uberoi, M. S., Chow, C. Y. & Narain, J. P. 1972 Stability of coaxial rotating jet and vortex of different densities. Phys. Fluids 15, 1718.Google Scholar
Uberoi, M. S., Shivamoggi, B. K. & Chen, S. S. 1979 Axial flow in trailing line vortices. To be published.