Vv. Meleshko et Gjf. Vanheijst, INTERACTING 2-DIMENSIONAL VORTEX STRUCTURES - POINT VORTICES, CONTOURKINEMATICS AND STIRRING PROPERTIES, Chaos, solitons and fractals, 4(6), 1994, pp. 977-1010
This paper addresses the stirring properties of interacting two-dimens
ional vortex structures. It is well known from previous studies that e
ssential features of dipole-dipole and dipole-monopole interactions, l
ike partner exchange, are captured by simple point-vortex models of th
ese structures. In order to investigate the mixing induced by such int
eractions, the method of contour kinematics is adopted here, which all
ows us to trace fluid particles that are initially confined within som
e closed contour. For example, by tracing the deformations of the sepa
ratrix enclosing the 'atmosphere' of a point-vortex dipole during the
interaction with another single point vortex or vortex pair, the conto
ur kinematics method provides information about the processes of entra
inment and detrainment that take place during the interaction. Compari
son of the modelling results with both full numerical simulations and
laboratory experiments on dye-visualised vortex interactions in a stra
tified fluid reveals a surprisingly good qualitative agreement.