Vortex Ring

Overview

Vortex Rings have an extraordinary ability to transport mass and momentum, due to its self-induced velocity. This ability is widely exploited in engineering applications, such as water purifiers, mixers, and conbustors. The vortex ring has been a subject of interest for more than a century, and many discoveries have been made about the generation process and transport mechnisms.

However, a large portion of these studies are based on the assumption that the surrounding fluid and the vortex ring have the same density. There are some circumstances where the fluid contained in the vortex ring has a smaller density. In this case the buoyancy acts against the propulsion, and the transport ability is greatly weakened.

Thus, it is important to invesigate the behavior of vortex rings moving against buoyancy, and to assess its transport ability and its retardment process.

The above movie shows the quilitative behavior of a vortex ring moving against buoyancy. (The yellow fluid is lighter)