What’s happening here?
- Thread starter Pond James Pond
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Pond James Pond
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OK. I'll try but basically it's a 7 sec slo mo vid of a HV bullet hit what looks to be 18" of ballistic gel.
It does a straight pass-through length-wise and as the bullet tumbles out of the other end, there is a flash in the temporary cavity which is clearly a small explosion to the point that when the cavity collapses again, grey smoke is expelled from the entry point!
It does a straight pass-through length-wise and as the bullet tumbles out of the other end, there is a flash in the temporary cavity which is clearly a small explosion to the point that when the cavity collapses again, grey smoke is expelled from the entry point!
I've seen that in a few gel videos.
When the gelatin collapses, the air inside the cavity is compressed extremely rapidly. When you very rapidly compress air in the presence of anything that is remotely flammable, the heat generated can rise to the point of causing the air/fuel mixture to burn.
Here's a good example of it:
https://www.youtube.com/watch?v=fX4ODh1g4eM
When the gelatin collapses, the air inside the cavity is compressed extremely rapidly. When you very rapidly compress air in the presence of anything that is remotely flammable, the heat generated can rise to the point of causing the air/fuel mixture to burn.
Here's a good example of it:
https://www.youtube.com/watch?v=fX4ODh1g4eM
Since Clear Ballistics Gelatin has a large percentage of paraffinic oil (which is quite flammable) within its composition this sort of thing is hardly remarkable. Rapidly compress a volatile, flammable vapor and you get adiabatic compression ignition (aka: dieseling). Pretty cool to watch though...
If this is caused by the diesel effect, yhen why hasn't it been seen, over the years, before in other slo- mo vids? What is the particular "fuel mixture" cause with this bullet caliber / rifle, hel composition, weather condition that would cause that? Surely, one of the bullet / powder mfgrs could find out.
It has been documented for quite some time, numerous videos exist dating back 5, 6, 7 or more years. A little google-fu turns up lots of videos like this one:
https://www.youtube.com/watch?time_continue=27&v=LhBBCOIjkiM
The fuel mixture is the paraffinic oil vapor that arises under the reduced vapor pressure and atmospheric O2 produced by the bullet's entry into the test medium, compression (thanks to the ideal gas law) increases pressure as the temporary cavity collapses and by extension of that law temperature increases proportionally causing auto-ignition to occur.
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In the mid 50s there were 500 cubic inch inline 6 cylinder engines that had a hemispherical piston design. It seemed it escaped the notice of most mechanics but the exhaust manifold was mounted on one side of the engine and the Intake manifold was installed on the other.
I understand none of this means nothing to reloaders but the mechanics rebuilt one of engines and then decided it did not need all of that plumbing so they left it off
Then came the time for the road test; they had to take the truck off the highway because it would quit running after a few miles. It bothered me to see that magnificent old truck confined to the yard for moving equipment locally.
F. Guffey
I understand none of this means nothing to reloaders but the mechanics rebuilt one of engines and then decided it did not need all of that plumbing so they left it off
Then came the time for the road test; they had to take the truck off the highway because it would quit running after a few miles. It bothered me to see that magnificent old truck confined to the yard for moving equipment locally.
F. Guffey
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reynolds357
New member
What changed? Laws of physics?
reynolds357
New member
Amazing it ran at all with the intake manifold left off.