Building an AIR CANNON, question
Building an AIR CANNON, question
(OP)
Considering pneumatic air cannons:
When the valve is opened and the air travels from the compressed air chamber to the barrel, is it desirable to have the valve/barrel openings the same or should it choke at the barrel?
Would a choke make the air move faster thus satisfying the momentum equation, or is this necessary at all?
When the valve is opened and the air travels from the compressed air chamber to the barrel, is it desirable to have the valve/barrel openings the same or should it choke at the barrel?
Would a choke make the air move faster thus satisfying the momentum equation, or is this necessary at all?





RE: Building an AIR CANNON, question
RE: Building an AIR CANNON, question
RE: Building an AIR CANNON, question
http://www.spudtech.com/
Incidentally, I noticed this is your first post here on Eng-Tips, and you might want to keep the questions work-related. I got red-flagged many moons ago for a question on air cannons.
Flores
RE: Building an AIR CANNON, question
Do you think this site may be monitored by Dianne Feinstein and, or Sara Brady?
If it is, we have problems in my opinion . . .
RE: Building an AIR CANNON, question
RE: Building an AIR CANNON, question
Only the OP knows.
BK
RE: Building an AIR CANNON, question
Mike Halloran
Pembroke Pines, FL, USA
RE: Building an AIR CANNON, question
A lot of times engineers (and non-engineers too) come up with some really creative and well engineered things at home for their hobbies, and sometimes they get stuck and need to ask for help. I've seen quite a few well engineered RC airplanes, weekend road racers, even home brew setups/tools, and if someone has a question about something like that, they should be able to ask it, as long as it's engineering related.
RE: Building an AIR CANNON, question
Not a trivial question indeed....
We have customer who has got an air cannon which fires an aluminium slug 500g (I think), at 400mph! It is used to test laminated ballistic screens for trains. The air reservoirs are about 6 ft diameter and about 15ft long x2. Great fun!
Rgds
Harry
RE: Building an AIR CANNON, question
The Federal Aviation Administration had an air cannon to shoot chickens at aircraft wind shields for certain tests.
It pales in comparison to the things the fanatics called Pumpkin Chuckers are producing now. This is some serious if light hearted engineering.
http://www.geocities.com/zbig10inch/
B.E.
RE: Building an AIR CANNON, question
RE: Building an AIR CANNON, question
Although a smaller barrel will have more air friction loss then a larger barrel, but the choke will have more air friction loss then a smaller tube.
To go into more detail, the size of barrel and pressure would need to be known.
RE: Building an AIR CANNON, question
Garland E. Borowski, PE
Borowski Engineering & Analytical Services, Inc.
Lower Alabama SolidWorks Users Group
RE: Building an AIR CANNON, question
Flores
RE: Building an AIR CANNON, question
I had some dealings with an air gun (cannon?) used for ballistic testing (3grms at 3km/s). This was two-stage so the first stage 'projectile' was a plastic plug that was forced down a tapering tube. This increased the pressure and hence speed applied to the second stage which had the specimen/sabot assembly. Guess you could play with the numbers to get the characteristics you want.
I played with the bird guns as well; 1kg at 480kts.
RE: Building an AIR CANNON, question
RE: Building an AIR CANNON, question
Flores
RE: Building an AIR CANNON, question
I don't think you should choke the barrel unless you
want to compress the wad holding a multitude of
projectiles to maintain a smaller pattern at a
given range, this is what a shotgun does. For accuracy
I would rifle the barrel, this of course would depend
on the projectile following the groves but smooth bore
is much easier. Maintaining minimal friction, maximum
gas seal and pressure throughout barrel travel is what
you need.
Chuck
A government which robs Peter to pay Paul
can always depend on the support of Paul.
- George Bernard Shaw
RE: Building an AIR CANNON, question