Geophysical flows affect the Earth's climate and weather and in these flows, dipolar vortices play an important role. In order to gain a better understanding of dipolar vortices, they are generated and studied in the laboratory. In this study, a novel method of electromagnetically generating symmetric dipolar vortices with improved control over propagation trajectory is investigated experimentally and numerically. As a first step, the generated dipoles have been characterized. In the formation phase, the dipole has two closely packed concentrated vorticity patches which is point-dipole-like. In the early time stage, the dipole is similar to a super-smooth dipole and in later time stages the dipole transitions into a more Chaplygin-Lamb dipole-like structure. Subsequently, the new generation method has been applied in various dipolar vortex collisions experiments where the collision outcomes are sensitive to small deviations in propagation trajectory, to highlight the improved control over the propagation trajectory. Lastly, the new method has been applied in experiments with a shearing background flow to illustrate the method's minimal intrusiveness in experiments, especially with background flows.
|Date of Award||30 Apr 2015|
|Supervisor||Vitor H. Marques Rosas Fernandes (Supervisor 1), L.P.J. Kamp (Supervisor 2) & G.J.F. van Heijst (Supervisor 2)|