Some aspects of near-surface vortices
An experimental investigation of the dynamics of near surface vortices is presented. Using digital particle image velocimetry, the velocity and vorticity fields of a vortex ring and a pair of undulated vortices were mapped as they rise toward a free surface. Circulation measurements indicate that vortex disconnection and appearance of the surface-normal vortices are simultaneous. Vortex disconnection due to the vorticity flux through the surface is shown to be related to the free-surface deceleration.
© 1994 American Society of Mechanical Engineers. This paper is based on experiments conducted by Dr. Alexander Weigand and Dr. Christian Willert. The majority of the results for the vortex pairs can be found in Dr. Willert's thesis and in an upcoming paper elsewhere. This work was sponsored by the Office of Naval Research URI grant (N00014-92-J-1610).
Published - Gharib_1994p157.pdf