The Vortex Cannon

By Riley Hooper

Introduction

Welcome to The Vortex Cannon. This is an informative slide show detailing the research and learning gained on the physics principles relating to my project and applications based on vortexes.

Initial Topics and Symbaloo Research

At the beginning of this project, we had to gather information about 6 possible final topics to use. My research was compiled on to my Symbaloo page. Some of the first projects I considered were:

 The Bicycle Wheel Gyroscope

Resonance Bowl

Newton's Cradle

Balloon Helicopter

Infinity Mirror, and 

The Vortex Cannon

http://www.symbaloo.com/shared/AAAABr7nN-IAA42ACqy6Jg==

My Choice

I am choosing to focus my project on the Vortex Cannon. My project will be based on the demonstration as seen on the Ellen Degeneres Show with Steve Spangler (Giant Smoke Rings - Cool Science Experiment). I am interested in this project because things like vortex cannons or air guns seem trivial, but can have some in depth analysis associated with them. My project will be fun, but it will also be a learning experience as well. I chose this project also because I wanted to learn more. I believed that the physics at work in this project could be interesting and challenging – which it was. Vortexes (and vortex cannons) can be intriguing and informative! It is an interesting project and that is why I picked it.

A Little About Pressure and Fluid Dynamics

Fluid Dynamics: How a fluid travels (Aerodynamics - the study of motion of air or gases)

This project demonstrates a toroidal vortex. A toroidal vortex looks a lot like a smoke ring when generated and can travel for long distances. As the membrane at the rear of the cannon excites the air particles and pushes them outward, they displace the air surrounding the hole outside of the cannon. The surrounding air will then swirl in the shape of a doughnut! This doughnut may travel very long distances due to its swirling motion.

A toroidal vortex is different from the types of vortexes you see in your sink or bathtub. The motion of the fluid makes it different. Its spiraling effect creates a stable motion which can carry the vortex and keep its shape over time.

Waves and SoundThis project can somewhat relate to our Waves and Sound unit. Recall that sound travels as a longitudinal wave and is created by pressure pushing air molecules and carrying sound waves. This relates to vortexes like the ones I will create. 

Toroidal vortices (Doughnut shaped air rings) form from a combination of friction and pressure. Pressure moves still air molecules through the hole in the cannon. Air molecules all around the sides of the group experience more friction than those in the center of the mass due to the size of the circular exit hole. This causes these molecules to move slower than the rest and spin back on itself, rolling the vortex into a doughnut shape. This doughnut shaped vortex remains very stable and travels, carrying either fog or smoke particles with it. This is also similar to a longitudinal wave, as both travel for very long distances. You may even hear a 'puff' sound, which is caused by the pressure of moving air molecules!

ApplicationsBattelle's vortex ring gun could deliver targeted dose of tear gas (article)

“Ohio-based research and development company Battelle has filed a patent application for a device that shoots out rings of gas. Such a system could help riot police deliver a targeted dose

of tear gas to particular individuals, or firefighters to clear rooms filled with smoke.Vortex guns have been around for years as toys and the US army has been investigating their

use for non-lethal crowd control, but Battelle's industrial version could have a range of commercial applications. The gun creates vortex rings by forcing gas at high velocity down the

gun's cylinder. The ring forms when the friction of the cylinder wall causes a thin layer of gas to roll forward on itself like a donut. The ring revolves on itself while travelling down and out of

the barrel -- a little like a tornado formed into a ring shape. As the ring leaves the chamber, the Battelle gun gives it a light electrical charge.

The donut shaped "smoke ring" can maintain stability for long distances -- Battelle estimates that a ring vortex can maintain a speed of at least 60 miles per hour for more than 50 yards.

The rings are stable even in a cross-wind.Such a vortex could be used to deliver tear gas or pepper spray to a particular individual in a

crowd, rather than throwing a canister that would not only target a much wider group of people but is also a projectile that could also injure someone.

Researcher Lynn Faulkner says that a vortex ring of ionised air could be used to clear smoke rapidly in a corridor or hallway to allow fire fighters to see. Similarly it could be used to 

disperse pests. Faulkner said: "If I have a wasp nest high up near the eave of my house I have to climb up there and spray. But with a vortex gun, I may be able to shoot a vortex of air

containing the pesticide and deliver it right on target."There is no date for a commercial launch for the vortex gun yet. You can watch a 

video of the gun in action though.”-An article taken from http://www.wired.co.uk/news/archive/2012-03/05/vortex-ring-gun

Final Thoughts & Questions

After completing this project, I am satisfied that I have learned a little more about physics and the complicated principles of fluid dynamics. I enjoyed the project overall and really liked how I could use a website to follow it along. The actual device was fairly simple and fun to use.

Final Questions:How can vortexes be used to improve everyday life?Can large scale vortexes have negative impacts on environments?What role do vortexes play in galaxy formations, and are they similar to the vortexes I am creating?How can other types of vortexes be demonstrated in small-scale?

The Final Product

A vortex of air knocks over two Styrofoam cups.

A vortex hits the camera.

Smoke rings!

Hooper 1

Bibliography

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2 Jan. 2014. <http://www.wired.co.uk/news/archive/2012-03/05/vortex-ring-

gun>

"Fluid dynamics." Wikipedia. Wikimedia Foundation, 1 Aug. 2014. Web. 6 Nov. 2013.

<http://en.wikipedia.org/wiki/Fluid_dynamics>

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<http://www.howitworksdaily.com/science/how-vortex-rings-form/>

"Physics demonstrations: vortex cannon!" Skulls in the Stars. N.d. Web. 20 Nov. 2013.

<http://skullsinthestars.com/2012/08/28/physics-demonstrations-vortex-cannon/>

"Physics in a Toroidal Vortex: Air Cannon." Physics Central. N.d. Web. 20 Nov. 2013.

<http://www.physicscentral.com/experiment/physicsathome/cannon.cfm>

“Sound is a Pressure Wave.” Sound is a Pressure Wave. N.d. Web. 11 Jan. 2014.

<http://www.physicsclassroom.com/class/sound/u1111c.cfm>

"Vortex." Wikipedia. Wikimedia Foundation, 1 Oct. 2014. Web. 10 Jan. 2014.

<http://en.wikipedia.org/wiki/Vortex>

"Vortex Rings - Science Tricks - Surfing Scientist - The Lab." Vortex Rings - Science

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<http://www.abc.net.au/science/surfingscientist/toroidalvortex.htm>