Note: This isn't for use in a cannon!
Just wondering what sort of length of 22mm pipe would generate DDT. The fuel is a ~1.1x oxy/hydrogen mix, and will have a single ignition at one end.
I have heard that hydrogen on its own will make the transition in 30cm of 50mm pipe (from an engineering PHD), but this doesn't sound right to me.
Any ideas?
22mm pipe DDT?
When we were discussing my proposed DDT gun, we decided that 20" of 1" pipe with oxy/hydrogen ignited at one end would detonate every time. For 22mm pipe, the required length would be a bit less.
If you want to reliably avoid DDT, don't use more than 3 times the diameter of the pipe for its length.
I don't know where the exact line is, but I'm fairly confident that these numbers, used properly, will achieve their desired affects. I'm assuming that, since you're using oxy/hydrogen, you want to generate DDT, probably for a noisemaker or something similar.
The D*6 number given by that PDF (?) sounds pretty close to me.
If you want to reliably avoid DDT, don't use more than 3 times the diameter of the pipe for its length.
I don't know where the exact line is, but I'm fairly confident that these numbers, used properly, will achieve their desired affects. I'm assuming that, since you're using oxy/hydrogen, you want to generate DDT, probably for a noisemaker or something similar.
The D*6 number given by that PDF (?) sounds pretty close to me.
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.
Thanks DYI, yeah it is for a noisemaker, simple but always impressive, most people don't appreciate the beauty of a silenced marble gun, but rather just enjoy a loud boom. PDF? PHD as in a doctorate, the guy was working on pharmaceutical production which involved piping in hydrogen - on a large scale production line DDT would be absolutely catastrophic.
Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety. -Benjamin Franklin
Ah, okay. The way you formatted the sentence made it seem as though you meant "from an engineering PDF", not "quoted from a PhD in (insert field of engineering here)".PDF? PHD as in a doctorate, the guy was working on pharmaceutical production which involved piping in hydrogen - on a large scale production line DDT would be absolutely catastrophic.
My cannon designs usually achieve the favourable attributes of both noisemakers and launchers on each shot, which is the effect I go for: impressive to bystanders, but still serving some more useful function than going BOOM.
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.
The hundreds of combined hours of work on the SpudWiki weren't just done for sh*ts and giggles you know.wtf is DDT. i keep hearing about it, and no amount of searching will show up what it actually stands for.
By opening a new tab, going to Spudfiles, then clicking on the SpudWiki link and typing "DDT" into the search bar, I found this in less than 30 seconds.
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.