Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-27T12:34:21.907Z Has data issue: false hasContentIssue false

Long's vortex revisited

Published online by Cambridge University Press:  26 August 2009

RICHARD E. HEWITT*
Affiliation:
School of Mathematics, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
PETER W. DUCK
Affiliation:
School of Mathematics, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
*
Email address for correspondence: richard.e.hewitt@manchester.ac.uk

Abstract

We reconsider exact solutions to the Navier–Stokes equations that describe a vortex in a viscous, incompressible fluid. This type of solution was first introduced by Long (J. Atmos. Sci., vol. 15 (1), 1958, p. 108) and is parameterized by an inverse Reynolds number ϵ. Long's attention (and that of many subsequent investigators) was centred upon the ‘quasi-cylindrical’ (QC) case corresponding to ϵ = 0. We show that the limit ϵ → 0 is not straightforward, and that it reveals other solutions to this fundamental exact reduction of the Navier–Stokes system (which are not of QC form). Through careful numerical investigation, supported by asymptotic descriptions, we identify new solutions and describe the full parameter space that is spanned by ϵ and the pressure at the vortex core. Some erroneous results that exist in the literature are corrected.

Type
Papers
Copyright
Copyright © Cambridge University Press 2009

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

REFERENCES

Burggraf, O. & Foster, M. 1977 Continuation or breakdown in tornado-like vortices. J. Fluid Mech. 80 (04), 685703.CrossRefGoogle Scholar
Drazin, P., Banks, W. & Zaturska, M. 1995 The development of Long's vortex. J. Fluid Mech. 286, 359377.CrossRefGoogle Scholar
Foster, M. & Jacqmin, D. 1992 Non-parallel effects in the instability of Long's vortex. J. Fluid Mech. 244, 289306.CrossRefGoogle Scholar
Foster, M. & Smith, F. 1989 Stability of Long's vortex at large flow force. J. Fluid Mech. 206, 405432.CrossRefGoogle Scholar
Keller, H. 1977 Numerical Solution of Bifurcation and Nonlinear Eigenvalue Problems (ed. Rabinowitz, P. H.), pp. 359–384. Academic Press.Google Scholar
Long, R. 1958 Vortex motion in a viscous fluid. J. Atmos. Sci. 15 (1), 108112.Google Scholar
Long, R. 1961 A vortex in an infinite viscous fluid. J. Fluid Mech. 11 (04), 611624.CrossRefGoogle Scholar
Pillow, A. & Paull, R. 1985 Conically similar viscous flows. Part 1. Basic conservation principles and characterization of axial causes in swirl-free flow. J. Fluid Mech. 155, 327341.CrossRefGoogle Scholar
Rosenhead, L. 1963 Laminar Boundary Layers. Oxford University Press.Google Scholar
Serrin, J. 1972 The swirling vortex. Phil. Trans. R. Soc. Lond. A 271 (1214), 325360.Google Scholar
Shtern, V. & Drazin, P. 2000 Instability of a free swirling jet driven by a half-line vortex. Proc. R. Soc. A 456 (1997), 11391161.CrossRefGoogle Scholar
Shtern, V. & Hussain, F. (1993). Hysteresis in a swirling jet as a model tornado. Phys. Fluids 5, 2183.CrossRefGoogle Scholar
Shtern, V. & Hussain, F. 1999 Collapse, symmetry breaking, and hysteresis in swirling flows. Annu. Rev. Fluid Mech. 31 (1), 537566.CrossRefGoogle Scholar