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Kwazai
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Hello

Post by Kwazai » Mon Jan 04, 2010 10:05 pm

Hello all,
just joined the forum and will be doing some posting not entirely directly related to pulsejets. I have been playing with sawdust stoves and stirling engines and am looking for a way to improve same. I am familiar with the Rijke and Sondhauss resonance calcs from the fluidyne stirlings and it seems that something similar is at work with pulsejets. I am a little disappointed with sawdust stoves and saw that some of the valvless pulsejet inventors were actually after 'ice melters' etc.. I thought I might be able to pick up some ideas to try with sawdust that incorporate pulsejet like construction. What I'm really after is a really hot sawdust flame (exhaust??) as most of the smudge pot diy sawdust stoves are only about 400-800F (max) output. any ideas/help would be appreciated.
L8r
Mike
Murphy's law 28th corollary-
If there are five ways for something to go wrong and you circumvent all five-then a sixth will promptly develop...
(Kwazai's addition--if you circumvent the sixth, then a seventh, etc.,etc.,etc.,...)

tufty
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Re: Hello

Post by tufty » Wed Jan 06, 2010 7:55 am

It's an interesting subbranch of the field, Mike.

Reynst's work is probably worth looking into, he was interested in maximum combustion efficiency rather than thrust output (at least, most of the time) and worked with coal powder amongst other things. Mike had a copy of "Pulsating Combustion" up on his site, (see here), a hardcopy version is more - well - physical, though. That's assuming you haven't already come across his work, of course.

Keep us posted, there's a few of us here interested in more than just pure thrust.

Simon

Kwazai
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Re: Hello

Post by Kwazai » Mon Jan 11, 2010 2:04 pm

I've been doing some research and run across a very good pdf paper-
http://fwc.com/publications/tech_papers ... _07_01.pdf
I have used it with my stirlings and it seems to be a good predictor of resonance. It looks at stability in relation to geometry and temperature parameters.
My 'sawdust' smudgepots are around 400-800 degF temperature and I've only just been able to get them hot enough for my stirlings to run. I put together a chimney of sorts (small inlet- large outlet,kinda looks like a ductwork pulsejet.) that I connected to one of the smudge pots, but still could not get the temperature up enough for resonance as predicted by the paper (700-1000degF).
I would wonder if there were a similar stability curve (from the pdf paper) for the pulsejets.
L8r
Mike
Murphy's law 28th corollary-
If there are five ways for something to go wrong and you circumvent all five-then a sixth will promptly develop...
(Kwazai's addition--if you circumvent the sixth, then a seventh, etc.,etc.,etc.,...)

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