This work shows visualizations with dye, tracer particles and shadowgraph of a vortex ring moving vertically within a linear stratified medium. The objective is to experimentally replicate vortex rings that form and evolve in the stratified atmosphere above craters of some volcanoes, such as Mount Etna.
The visualizations show that vortex collapse a few centimeters above their ejection. A comparison is made with a vortex, with the same characteristics, that moves vertically in a homogeneous medium.
The vortex is made up of low density water (fresh water) and the stratified medium varies its density linearly from 10% salt water at the bottom to fresh water at the top. It was expected that the variation in the buoyant force would contribute to a long displacement of the vortex. Nevertheless, its collapse indicates otherwise. One possibility is the entrainment of high density fluid in the low density region.
Work supported by the UNAM-DGAPA-PAPIME program #PE105716.