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Vortex rings big and bigger.

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Steve Ward

Tue Aug 15 2006, 05:49PM

Registered Member #146 Joined: Sun Feb 12 2006, 04:21AM
Location: Austin Tx
Posts: 1055

Hi, i saw the "cannon" first hand. The red part (where the combustion takes place) is 1" thick steel pipe. The blue part is fairly thin, maybe 14awg metal. They pump the chamber full of hydrogen (and i think some oxygen too, but maybe there is already enough there) and ignite it with an ignition coil. It makes one hell of a boom, and scared the sh*t out of me when he first fired it (and im no stranger to loud booms). The sound was enough to set off car alarms nearby. As to its effectiveness at shooting a powerful burst of air seems a little poor. I didnt even really notice the trees (which were maybe 150' away) move very much from the firings. There were some videos where you can see the ring traveling pretty fast, but i guess it dissipates pretty quickly. Thats about all i know.

Tesladownunder

Tue Aug 15 2006, 06:54PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

I'm sure DC spent a lot of time and thought designing this. I wonder if it is optimised for vortex ring production though or if that was even the aim. A vortex ring typically travels 100 times the radius so 150 ft range might be close to the limit and this one looks like it was expanding rapidly.
Ordinary big bore cannons do have a ring vortex shape to the outflow but it expands very rapidly and is much larger than the barrel in a short time which is quite different to mine.
A larger vortex cannon is here for wind research and uses ignition of 90g of aluminium to propel 6 cubic meters.

Peter

Tesladownunder

Wed Aug 23 2006, 01:42PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Demonstrated the Vortex ring generator outside the physics dept at the Uni open day. It was very popular. A few sample pics give the idea.

Peter

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Mike

Sat Aug 26 2006, 07:56AM

Registered Member #58 Joined: Thu Feb 09 2006, 05:40AM
Location: Tri-Cities, Washington, US
Posts: 317

Hmm, I am still waiting on some explosive pics.

I take my air cannon and pour about 250ml of Gasoline down the barrel, then put a stick in the ground with some paper soaked in gas on fire sitting on top, and aim the cannon and fire, it makes a heck of a fireball. I have done it quite a few times and I am pretty certain it wont relight the trail. As for a vortex cannon I guess it depends how fast the air is moving?

Cool stuff though.

Mike

Alex

Sun Aug 27 2006, 03:40AM

Geometrically Frustrated
Registered Member #6 Joined: Thu Feb 02 2006, 04:18AM
Location: Bowdoin, Maine
Posts: 373

Has anyone tried firing gases much lighter or heavier than air? Perhaps CO2 or helium, as they are fairly easy to get.

Nik

Sun Aug 27 2006, 05:02AM

Registered Member #53 Joined: Thu Feb 09 2006, 04:31AM
Location: Ontario, Canada
Posts: 638

I saw vidoes of some one using propane in an airzooka. Im sotty i dotn have the url but its a wonder they were not killed in the stunt. The airzooka was placed less then a foot fromt he ignition source and onyl produced a breif ring of fire.

Tesladownunder

Sun Sept 24 2006, 01:26AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

The Physics Dept was keen on a vortex generator for school demos so I made one.
Features of this one:
Portability - well it is a wheelbarrow so easy to get around. Uses a 220 liter compost container.
Light.
Larger rear diaphragm to shift a good amount of air.
Diaphragm is more flexible and lower for kids to use.

All up cost with new parts was AU$220 (apart from 4 old bike tubes). No screws and can be disassembled in a flash (well sort of falls apart).

But the best part is that it looks mean with a light inside it

Peter

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Tesladownunder

Sat Jan 20 2007, 06:11AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

I am now mobile with my vortex generator. My 300W Honda generator is a bit weak for the 700W smoke generator so has to run through a variac and takes longer to heat.
Add a lick of paint, wheels and a trailer and I can take it anywhere. Had vague ideas of the kids having a small business hiring this out for kiddies birthdays and the like.

Still would like to make a huge one to fire vertically. Or a truck sized one to fire at crowds at events.

Peter

Bjørn

Sat Jan 20 2007, 07:49AM

Registered Member #27 Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058

Very nice.

It is possible to make gigantic vortex rings that can be visible for a whole town using a bucket and some additions.

Tesladownunder

Sun Jan 28 2007, 05:47AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Hard to judge how big that one is. Making a lot of black smoke might not go down so well in these environmentally conscious times and explosive devices will be subject to all sorts of regulations.

Just so you people on the cold side of the world can see what life is like over here, the photos show my son blowing underwater vortex rings in our pool.

Peter

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