![](https://i0.wp.com/www.flowvis.org/wp-content/uploads/2021/11/DSC09395_website.jpg?resize=1024%2C709&ssl=1)
To create this image I cut a hole in a fish tank and made an external reservoir to hold the food coloring dye. The reservoir had a rubber membrane on the outermost side of it so it could be depressed to generate the toroidal vortex ring.
To create this image I cut a hole in a fish tank and made an external reservoir to hold the food coloring dye. The reservoir had a rubber membrane on the outermost side of it so it could be depressed to generate the toroidal vortex ring.