One of Make: magazine's first articles was on making a pulsejet from a jam jar: http://makezine.com/projects/make-05/jam-jar-jet/ If you build this, it makes repetitive flame fronts just like this. It's spectacular. Runs pretty well using ethanol as fuel, too.
(I advise putting a bit of tape around the glass jar, because, y'know, repeated explosions in a glass jar, but it is gorgeous to watch, and pretty cool to listen to. WHUFF!whuffwhuffwhuffwhoompwhoompwhoomprappettypappety as it heats up and runs faster.)
Pulse jets are really cool and only seem more dangerous than they really are. Vessel integrity is pretty much your only concern. https://www.youtube.com/watch?v=D1EHZPjLNHk
Sam Collett -- this is probably burning alcohol or a ketone, hence the blue of oxygen-rich fuel. You can do atomic emission spectroscopy with one if you want, though: boraxo soap will give it a green color, the strontium nitrate from a road flare will make it red, sodium salts yellow-orange, although they don't make it into the vapor (they stay in the liquid) so it requires the physical and thermal agitation of the pulsejet to get much color into the flame.
One of Make: magazine's first articles was on making a pulsejet from a jam jar: http://makezine.com/projects/make-05/jam-jar-jet/
ReplyDeleteIf you build this, it makes repetitive flame fronts just like this. It's spectacular. Runs pretty well using ethanol as fuel, too.
Ridiculously awesome :D
ReplyDeleteDanke John Bump
(I advise putting a bit of tape around the glass jar, because, y'know, repeated explosions in a glass jar, but it is gorgeous to watch, and pretty cool to listen to. WHUFF!whuffwhuffwhuffwhoompwhoompwhoomprappettypappety as it heats up and runs faster.)
ReplyDeleteI'd like to see it in different shapes, maybe even multicoloured. Which element causes the blue colour?
ReplyDeletePulse jets are really cool and only seem more dangerous than they really are. Vessel integrity is pretty much your only concern.
ReplyDeletehttps://www.youtube.com/watch?v=D1EHZPjLNHk
Sam Collett -- this is probably burning alcohol or a ketone, hence the blue of oxygen-rich fuel. You can do atomic emission spectroscopy with one if you want, though: boraxo soap will give it a green color, the strontium nitrate from a road flare will make it red, sodium salts yellow-orange, although they don't make it into the vapor (they stay in the liquid) so it requires the physical and thermal agitation of the pulsejet to get much color into the flame.
ReplyDelete