Jam Jar Pulse Jet in the Dark!

The tin can pulse jet seemed to be one of your favotite videos lately so i decided to make a jam jar version of this. Also i did this test in the dark because in my tin can video i wanted the pulsating flame from the exhaust to be visible but the result wasn't truly representantive of the violent flames this thing produces. Last but not least i want to mention that for some reason the jars kept breaking and i could make a decent footage out of them.

[Spoif]

On the Bonne Maman jar, it says, "suitable for conversion into pulse jet combustion chamber". 8)

[goyabee]

Do we think warming the jar first would help reduce thermal disequilibrium and therefor lessen thermal stress? The idea of immersing the jar in water that someone mentioned sounded good, too. I would think that it's not the heat that causes the break but the difference in temperature from one part of the glass to another. Preheating the glass seems like it would help with this problem.

[marcoabduarte]

HOW IS THE 3RD JAR DOING? IS SHE BROKEN YET?
I NEED

[thelongslowgoodbye]

I never thought that my favourite brand of jam, Bonne Maman, could be used as a homemade pulse jet.

[BangAsoursRex]

Jar #3 sounds almost like a top fuel funnycar

[seededsoul]

Can you put this on a scale to see how much thrust they produce?

[TheFlacker]

Wow making a pulse jet seems relatively easy. New subscriber here.

[MisterFanwank]

It's neat that this design can create self-sustaining combustion, but it seems like the vacuum would counteract a lot of thrust.

[LilRay.]

#3 sounds like a dragsters cam🔥🔥 could listen to that jar all dayy😭😍

[IndiaEllisonHealthyLiving]

That's really cool, I'm gonna try it tomorrow

[dancoulson]

Could you place a small jar inside of a larger jar, with magnets holding it down. Then fill the gap between the two jars with water to keep it from overheating?
Might be worth a shot.

[andrewharbit]

Love the video, it has inspired me to make a small motor perhaps ill post when its done

[meteorshower]

I reckon the reason why the first two jars broke is the difference in temperature. As it warms up, different sections of the glass expand differently. This creates the stress in certain places in the jars then it fractures, I.E. why it's call a stress fracture. The reason the third jar may still be going is because it looked like a thicker walled jar, so it would be stronger, or at least theoretically. Damn cool it looks as well.

[Convolutedtubules]

Try submerging it in water to keep it cool constantly

[nameismetatoo]

Wild to think that pulse jets could theoretically have been invented before the steam engine, given that they really only need a container with a small opening and some volatile and flammable substance like alcohol.

[ROFLCOPTERS]

So, how does this work without just exploding? What other things can fuel it other than rc fuel and isopropyl alcohol(i saw in another video)? Seems really cool!Is there a certain amount you have to put in the container?

[EuphCat]

I want to see this with high speed camera to see what exactly happens. Cool video!

[hell]

La confiture bonne maman est toujours la meilleurs ;)

[Latrocinium]

The jars are popping from thermal shock.
Put it in a cake pan and put some water in the cake pan. This will dampen the effects and keep your jars from exploding.
Also a lot of fuel. You just want enough to coat the inside and a little on the bottom.

[kandreas]

πάντα την εκτιμούσα αυτή τη μαρμελάδα, και το βαζάκι της.ωραίος