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The oblique ascent of a viscous vortex pair toward a free surface

Published online by Cambridge University Press:  26 April 2006

Hans J. Lugt
Affiliation:
David Taylor Research Center, Bethesda, MD 20084-5000, USA
Samuel Ohring
Affiliation:
David Taylor Research Center, Bethesda, MD 20084-5000, USA

Abstract

The problem of a vortex pair, rising obliquely at an angle of 45° toward a deformable free surface in a viscous, incompressible fluid, is solved with the aid of the Navier—Stokes equations. The full nonlinear boundary conditions at the free surface are applied. The oblique interaction of the vortex pair with the free surface results in a number of novel features that have not been observed for the special case of a vertical rise, reported earlier. These features include the directional change of trajectories near the free surface and the occurrence of waves driven by the vortex pair. Moreover, surface tension can completely change the flow characteristics such as the direction of the trajectories and the generation of secondary vortices. Numerical solutions are presented for selected Reynolds, Froude, and Weber numbers.

Type
Research Article
Copyright
© 1992 Cambridge University Press

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References

Acton, E. 1976 The modelling of large eddies in a two-dimensional shear layer. J. Fluid Mech. 76, 561592.Google Scholar
Bernal, L. P. & Kwon, J. T. 1989 Vortex ring dynamics at a free surface. Phys. Fluids A 1, 449451.Google Scholar
Couder, Y. & Basdevant, C. 1986 Experimental and numerical study of vortex couples in two-dimensional flows. J. Fluid Mech. 173, 225251.Google Scholar
Dommermuth, D. G. & Yue, D. K. P. 1990 A numerical study of three-dimensional viscous interactions of vortices with a free surface. In Eighteenth Symp. on Naval Hydrodynamics, The University of Michigan, Ann Arbor, Michigan, pp. 161.
Dritschel, D. G. 1989 Strain-induced vortex stripping. In Mathematical Aspects of Vortex Dynamics (ed. R. E. Caflish), pp. 107119. SIAM.
Ersoy, S. & Walker, J. D. A. 1986 Flow induced at a wall by a vortex pair. AIAA J. 24, 15971605.Google Scholar
Harvey, J. K. & Perry, F. J. 1971 Flowfield produced by trailing vortices in the vicinity of the ground. AIAA J. 9, 16591660.Google Scholar
Heijst, G. J. F. van & Flor, J. B. 1989 Laboratory experiments on dipole structures in a stratified fluid. In Proc. 20th Int. Liege Colloq. on Ocean Hydrodynamics, pp. 591608. Elsevier.
Kida, S. 1981 Motion of an elliptic vortex in a uniform shear flow. J. Phys. Soc. Japan 50, 35173520.Google Scholar
Kwon, J. T. 1989 Experimental study of vortex ring interaction with a free surface. Ph.D. thesis, University of Michigan.
Lim, T. T. 1989 An experimental study of a vortex ring interacting with an inclined wall. Exps. Fluids 7, 453463.Google Scholar
Lo, R. K. C. & Ting, L. 1976 Studies of the merging of vortices. Phys. Fluids 19, 912913.Google Scholar
Lugt, H. J. 1987 Local flow properties at a viscous free surface. Phys. Fluids 30, 36473652.Google Scholar
Nguyen Duc, J. & Sommeria, J. 1988 Experimental characterization of steady two-dimensional vortex couples. J. Fluid Mech. 192, 175192.Google Scholar
Ohring, S. & Lugt, H. J. 1989 Two counter-rotating vortices approaching a free surface in a viscous fluid. David Taylor Research Center Rep. DTRC-89/013 (referred to herein as I).Google Scholar
Ohring, S. & Lugt, H. J. 1991 Interaction of a viscous vortex pair with a free surface. J. Fluid Mech. 227, 4770 (referred to herein as II).Google Scholar
Polvani, L. M. & Wisdom, J. 1990 On chaotic flow around the Kida vortex. In Topological Fluid Mechanics (ed. H. K. Moffatt & A. Tsinober), pp. 3444. Cambridge University Press.
Sarpkaya, T. & Henderson, D. O. 1984 Surface disturbances due to trailing vortices. Naval Postgraduate School Monterey, California, Rep. NPS-69–84–004.Google Scholar
Ting, L. 1981 Studies on the motion and decay of a vortex filament. In Advances in Fluid Mechanics Conf. Aachen Lecture Notes in Physics, vol. 148, pp. 67105. Springer.
Willmarth, W. W., Tryggvason, G., Hirsa, A. & Yu, D. 1989 Vortex pair generation and interaction with a free surface. Phys. Fluids A 1, 170172.Google Scholar