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Interaction of a viscous vortex pair with a free surface

Published online by Cambridge University Press:  26 April 2006

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

Abstract

A vortex pair in a viscous, incompressible fluid rises vertically toward a deformable free surface. The mathematical, description of this flow situation is a time-dependent nonlinear free-surface problem that has been solved numerically for a two-dimensional laminar flow with the aid of the Navier-Stokes equations by using boundary-fitted coordinates. For a number of selected flow parameters, results are presented on the decay of the primary vortices and their paths, the generation of surface vorticity and secondary vortices, the development and final stage of the disturbed free surface, and the influence of surface tension. High and low Froude numbers represent the two extremes of free-surface yielding and stiffness, respectively. For an intermediate Froude number, a special rebounding due to the presence of secondary vortices has been observed: the path of the primary vortex centre portrays a complete loop.

Type
Research Article
Copyright
© 1991 Cambridge University Press

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