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Built a combustion cannon? Then post it here! This section is for completed, finished cannons that you have built. Please include pictures and information.
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Unread postAuthor: Petitlu » Fri Jun 08, 2012 8:21 am

But you have no fan inside ?
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Unread postAuthor: jackssmirkingrevenge » Fri Jun 08, 2012 9:19 am

Petitlu wrote:But you have no fan inside ?


Yes, here it is:
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Unread postAuthor: Petitlu » Fri Jun 08, 2012 9:25 am

ok !
Good ! :D
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Unread postAuthor: Petitlu » Fri Jun 08, 2012 1:36 pm

test fan on :

[youtube]http://www.youtube.com/watch?v=qw5lsd4Tkfg[/youtube]
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Unread postAuthor: POLAND_SPUD » Fri Jun 08, 2012 4:13 pm

got me a new fridge compressor - got to build a hybrid
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Unread postAuthor: Petitlu » Fri Jun 08, 2012 4:19 pm

well!
Attention, the air leaving the compressor freezer often contains oil !
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Unread postAuthor: ramses » Fri Jun 08, 2012 8:58 pm

Interesting video. I don't really seem much difference in propagation between fan on and fan off. Perhaps even the existence of the fan in the chamber creates enough turbulence to accelerate the burn...
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Unread postAuthor: Petitlu » Sat Jun 09, 2012 2:25 am

I agree with you! obstructs the fan in the chamber and that's enough for combustion
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Unread postAuthor: POLAND_SPUD » Sat Jun 09, 2012 4:38 am

Attention, the air leaving the compressor freezer often contains oil !
OH RLY ?? :D
Interesting video. I don't really seem much difference in propagation between fan on and fan off.
Sure but a fan can help in mixing
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Unread postAuthor: boyce123 » Sat Jun 09, 2012 9:49 am

the burn patterns are surely different, but its hard to tell which propogates at a faster rate. The one with the fan on shows a spiraling burn pattern that entirely burns all to fuel, where as the one without the fan on appears to burn with a convection chamber pattern, with the initial burn, and a subsequent burn of all the fuel that was missed by the initial burn (because of fan's intrusion generating a convection cycle). The double burn was shown in the first videos quite well. The exsistance of the double burn, as shown in the first videos, appears to require a longer barrel to utilize the full power of the second burn; so if anything, the fan being on would allow the full potential of the gun to be met with a shorter barrel (or for more power to be utilized out of a given length of barrel).
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Unread postAuthor: Petitlu » Thu Jun 14, 2012 2:57 pm

I did further testing by placing the electrode in the center. The ignition system is always a flash + transformer It is crucial to a fan in a chamber!

[youtube]http://www.youtube.com/watch?v=KM1HKaBq7Jc[/youtube]
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Unread postAuthor: Labtecpower » Thu Jun 14, 2012 3:12 pm

Ignition behind the fan seems more effective to me!
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Unread postAuthor: Petitlu » Thu Jun 14, 2012 3:15 pm

the fan obstructs the combustion when the ignition is in the center
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Unread postAuthor: ramses » Thu Jun 14, 2012 9:04 pm

I wonder what all those little "balls" of fire were in the last video? I would have to guess either poor mixing (not likely if you ran the fan before the shot).

It cannot be dieseling or anything, since it only occurs where the flamefront has passed.
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Unread postAuthor: Petitlu » Fri Jun 15, 2012 12:27 am

These are small pieces of Kleenex paper from the barrel ! :D

EDIT :
I just had an idea but I do not know if it's good! : face:

By putting a mano on the chamber, we could measure the peak pressure during combustion is not it?
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