Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
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matti
- Specialist 2


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Thu Feb 04, 2016 4:58 am
Hey !
quick question.. Do any of you remember if there is cannons here that work with atmospheric oxy/propane mix ? (open chamber, not hybrids).
I know there probably is, but can't seem to find them now..

Links ?
I'm interested how will the atmospheric oxy/propane mix compare to 4x mix hybrid. Any experience/knowledge on this ?
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DYI
- First Sergeant 5


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Thu Feb 04, 2016 6:43 pm
I don't have any links offhand, but I did build one back in '07, before I joined Spudfiles. The maximum combustion pressure in such a mix can be about 23atm, as opposed to about 8atm for an air/propane mix. This occurs around 3:7 oxy/propane, as predicted by GasEQ (which you really should be using, if you're not already).
Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
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Zeus
- Staff Sergeant

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Fri Feb 05, 2016 3:16 am
Careful DYI, we're being wiretapped...
/sarcasm, /hyperbole
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matti
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Fri Feb 05, 2016 3:19 am
DYI wrote:I don't have any links offhand, but I did build one back in '07, before I joined Spudfiles. The maximum combustion pressure in such a mix can be about 23atm, as opposed to about 8atm for an air/propane mix. This occurs around 3:7 oxy/propane, as predicted by GasEQ (which you really should be using, if you're not already).
I did try it (GasEq) but i'm not sure if I got everything correct, could you post a screenshot of any oxy/propane mix, that way I could check if I get same numbers
Just to be sure.. What "problem type" I should use when modeling a combustion cannon or to find the max pressure in closed chamber ?