Some noob ideas for initiator

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Some noob ideas for initiator

Post by Röör » Mon Feb 08, 2016 7:23 pm

As I was just going though the forum, I had now a look at these PDEs, which I never have done before.

Interesting concept, but as it seems unfortunately quite a small amount of info out there...

As I got it, there are several concepts.
One of them being basically a double chamber setup, where the first small chamber uses a hydrogen oxygen mixture to create the detonation wave which then triggers the fuel air mixture in the bigger adjacent chamber.

Now a few thoughts ideas about this version.

Wouldn't it be simpler to directly feed a high pressure electrolyzer to the first chamber. Like that without much effort you get the ideal ratio of hydrogen and oxygen without needing any additional high pressure containers, just a bit electric energy...
Maybe one could even include the electrolyzing part directly into the initiator chamber.

I know from personal HV experiments that a bigger capacitor bank discharge will clearly lead to a detonation like shock front. If you discharge into a plasma focus you even get a directed shock (toroidal vortex)
Wouldn't that also do as an initiator? Purely electrical. Sure it would need some energy...

I basically also did some years ago experiments with a mixed version of the above, where you have some tiny amount of water between the electrodes in a plasma focus.
When you then have the correct discharge curve (first "low voltage" discharge (mains voltage), then HV trigger and then rest of LV (very high current)), the water in between the electrodes first gets electrolyzed also the pressure increases as the gap is long and narrow, then a spark build and the actual plasma focus starts to fire by at the same time again trigger the combustion of the hydrogen and oxygen gas. This always resulted in strong directed pressure waves.
I experimented back then a bit to make holes in wood panels etc...LOL...just for fun...

Back then I realized that the final discharge really has to be high current, that's why I used there special high current capacitors capable of repeated several thousand amp discharges...

Back on topic. I could imagine that one could maybe use that as an initiator-device to trigger the fuel/air mixture...
As said, just a noob idea...
But I have to admit that the wear on the electrodes was quite extreme...

But what I really didn't really got about these PDE's. How to make them in a good valveless version?
IMHO I could only imagine doing it like a VPJ, but with a timing which shots the initiator right before the VPJ would fire by itself...
Would that work?

I also saw ideas which looked like ramjets without flameholders, where you just repeatedly fire such an initiator shockwave into the fuel/air mixture. But I would think that this is very hard to time, that there is no unburnt fuel going out of the nozzle between shots. I also wonder why the detonation pressure wouldn't come out of the front also? At least if it isn't supersonic.

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Re: Some noob ideas for initiator

Post by zono » Sun Dec 11, 2016 11:55 am

nice ideas.

please have a look on my posts in thread "predator". This works vaveless without shockwave primers by just initiating high turbulences by the propane injector. But with very low pulse-frequencies.

Initiating electrical shocks by capacitor banks are anyway interesting alternatives. Can you post some informations and pictures of your plasma-focus experiments?

I would appreciate.
zono - the thruster buster

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