Video Of Two Fluid Vortex Rings Colliding Perfectly Head-On In Slow Motion

June 21, 2018

This is a video over four years in the making of Destin from Youtube channel SmarterEveryDay and his quest to recreate this previously posed old scientific video of two fluid vortex rings colliding perfectly head-on, but recorded with today's latest high definition, slow-motion cameras. *shrug* I'm guessing our bucket lists aren't identical. Just a taste of everything that went into this experiment:

We used a computer controlled cylinder to pump fluid behind a rubber membrane to fire toroidal vortices out of the vortex cannons.

We fixed one of the vortex cannon in a stationary position, and used a multi-axis microscope stage to align a second cannon to it... which sounds incredibly easy, until you realize that

DYE density was an experiment all on its own.
If the density of the dye mix was light than water, the vortex would go up.
If the dye was more dense than water the vortex would fall.

We had to overcome SO MANY VARIABLES to overcome and we basically spent about 4 hours figuring each variable.
Water/dye temperature differential
Water turbulence
Water turbidity (cloudiness or haziness of a fluid)
How to reset the aquarium
Cannon Spacing
Cannon Nozzle
Cannon Shape
Dye homogeneity in the vortex itself
The piston displacement volume
The piston stroke speed
Rubber diaphragm tension, would make one side fire faster than the other.
Water or air to drive diaphram?
Firing speed (too slow and they drift, too fast and turbulence tears apart secondaries)
We did a complete redesign of the cannon 3 different times.
The Dye loading method was changed several times
At times We tried to maintain negative pressure on the cannon chamber... we also tried to put shutters on the front of the muzzle. Ultimately I decided it was ok to live with dye dripping out of the front.

We had to premix the dyes and eventually we got there.

It got to the point where we didn't even really know what success looked like and always thought we were there.

Fluid dynamics, am I right? "What about them?" No clue, everything I've ever learned about fluid dynamics I learned from hocking loogies. "You have spit all over your shirt." Sure, so I'm probably not ready to teach a college course about it yet. Definitely getting close though.

Keep going for this video, as well as a 12-hour edit that chronicles the whole journey in case you're working overtime today but not really working.

Thanks to John S, who agrees the secret to throwing hadouken punches has got to be here somewhere.

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