Experiment on the self-propagating quasi-monopolar vortex

The aim of this contribution is to present the results of laboratory experi ments on the dynamics of basic self-propagating vortices generated in a lar ge volume of fluid when a linear (P) and an angular (M) momentum are applie d locally to a fluid. Using the method proposed, it is possible to generate a whole family of isolated (net vorticity is equal to zero) vortices with different values of the nondimensional parameter epsilon, which is proporti onal to the ratio of linear to angular momentum (epsilon proportional to RP /M, R is the eddy size). Typical examples include monopole (epsilon = 0), q uasi monopole (epsilon = 0.1-0.3), quasi dipole (epsilon approximate to 1), and dipole (epsilon = infinity). One of the possible applications is the dynamics of oceanic eddies. Recentl y, Stern and Radko considered theoretically and numerically a symmetric bar otropic eddy, which is subject to a relatively small amplitude disturbance of unit azimuthal wavenumber on an f plane. This case corresponds to a self -propagating quasi monopole. They analyzed the structure of the eddy and pr edicted that such an eddy remains stable and could propagate a significant distance away from its origin. This effect may be of importance for oceanog raphic applications and such an eddy was reproduced in laboratory experimen ts with the purpose of verifying these theoretical predictions. Another possible application may include large eddies behind maneuvering bo dies. Recent experiments by Voropayev ct al. show that, when a submerged se lf-propelled body accelerates, significant linear momentum is transported t o the fluid and unusually large dipoles are formed in a late stratified wak e. When such a body changes its direction of motion, an angular momentum is also transported to the fluid and the resulting structure will depend on t he value of epsilon.