Air rings blown by dolphins swimming underwater and rings of smoke emitted by jet engines are just two examples of vortex rings.
Air rings blown by dolphins swimming underwater and rings of smoke emitted by jet engines are just two examples of vortex rings.
These doughnut-shaped structures and their mesmerizing movement have been studied for decades given their role in propulsion and—in the case of jellyfish and other invertebrates—biological locomotion.
A team of researchers at New York University and NYU Shanghai has uncovered a remarkable property of vortex rings that had been overlooked for more than a century—one that illuminates how these rings respond when they move through water and reach air (i.e., at the water-air interface).
When a vortex ring traveling sideways and up through water reaches the surface and meets air, it can rebound while largely maintaining its shape—much like a tennis ball bouncing off a wall. After the reflection, the ring loses only a small fraction of its energy.
Read More: New York University
Photo Credit: MartinStr via Pixabay
