Experimental and Computational Study of Vortex Rings in Water Subject to Coriolis Forces induced by Background System Rotation - 1=Engineering

The goal of the proposed project is to investigate the fundamental physics governing the dynamics of vortex rings subject to background system rotation. The dynamics of vortices affect the vast majority of applied engineering problems involving liquids or gases. Vortex rings are a geometrically simple vortex structure that has served for decades as a paradigm to study general issues associate with physics governing the formation, the motion, the stability and the laminar-turbulent transition of vortices. Vortices are also the fundamental flow structures underlying and governing fluid turbulence. Turbulence is considered to be the outstanding unresolved problem of classical mechanics.

Coriolis forces associated with background system rotation fundamentally alter fluid flows and lead to many counterintuitive phenomena entirely unknown in non-rotating flows. Rotating flows are prevalent in applied engineering contexts. The effects of background rotation on vortex rings are an essentially entirely unexplored research area. One of the only existing publications is by the project supervisor Prof. P.J. Thomas. The reason why publications on the subject are scarce is because only a very small number of laboratories have the required infrastructure available to perform the necessary experiments.

Since our previous publication, the relevant measurement techniques (Particle Image Velocimetry ) required to obtain data for the problem considered have substantially advanced. It is therefore timely to readdress the issue of the effects of Coriolis forces on the dynamics of vortex rings by means of modern state-of-the-art measurement methodologies. In our previous publication many new flow phenomena were identified qualitatively but, at the time, had to remain unexplored in detail since the computer-aided measurement technology had not advanced to a stage that enabled the required quantitative measurements. However, these measurements can now be performed and it is planned to conduct these and compare the data to be obtained to results of concurrent computational simulations.