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Re: Proposed Design - Straight Pipe 'Henri' Valveless Pulsej

Posted: Fri Mar 11, 2005 11:06 pm
by steve
Interesting idea, seems very Reynst-ish.
http://www.pulse-jets.com/phpbb2/files/ ... st_171.jpg

BTW welcome to the forum!

have you built any engines, or are you just looking right now?

Re: Proposed Design - Straight Pipe 'Henri' Valveless Pulsej

Posted: Sat Mar 12, 2005 12:37 am
by Mike Everman
Bruno Ogorelec wrote:Machine a steel plug for a fit so tight you cannot press it in without a mallet. Put the plug into deep freeze. Take out, hammer it in (it will be smaller and easier to push in), let it thaw. Presto! A fit so tight you won't take it out very easily anymore. Pulsejet operation will only make it tighter still.
I tried the press fit method, granted I did not really try too hard, nor was it the thermal interference you're describing. unfortunately, Bruno, the head plate or plug stays cooler than the chamber wall gets, I think. The heat will relieve the stress you want in the press. Mine went from merely leaky to downright rattling. I had a press and then ran a pipe cutter fore and aft of the washer that was my press-fit bulkhead. I think the CC tube needs to press inside the bulkhead for best chance at it. and add some muffler bond, too.

Re: Proposed Design - Straight Pipe 'Henri' Valveless Pulsej

Posted: Sat Mar 12, 2005 2:04 am
by Mark
mk wrote:
Mark wrote:[...] And then sell it on eBay. [...]
...with the attached explanation, of course. 100 percent serious...hehehe...

Safed my day again. Thanks Mark.
How about a young girl buying some pretzels in Nebraska, next door neighbor to Larry, and selling it for more than the few dollars she paid for the bag of pretzels. I think we should be designing Virgin Mary pulsejets to sell on eBay. This topic/pretzel was on CNN news this morning too!
Mark
http://www.usatoday.com/tech/news/2005- ... tzel_x.htm

Re: Proposed Design - Straight Pipe 'Henri' Valveless Pulsej

Posted: Sat Mar 12, 2005 3:18 pm
by larry cottrill
Mark wrote:How about a young girl buying some pretzels in Nebraska, next door neighbor to Larry, and selling it for more than the few dollars she paid for the bag of pretzels. I think we should be designing Virgin Mary pulsejets to sell on eBay.
I don't think it would take much to do that by design, but to be valuable it would have to be something that occurs naturally or accidentally, like the shape of heat discoloration somewhere after the engine's first run or some such. You can't manufacture miracles that sell, you have to take them where you find them.

To show how much of a brilliant entrepreneur I am: If I had run across that pretzel out of a vending machine bag at work, I would have shown it briefly to the person in the next cubicle with some comment like, "Hey - check this out!" a second or two before popping it in my mouth and destroying it forever.

What amazes me about these incidents is not the imputed religious meaning but the incredible human penchant for anthropomorphism. It seems ridiculous to think of dogs, cats or horses going through life seeing hundreds of objects that remind them of themselves, but with humans all it takes is a squiggly line on a piece of paper (or a quirky pretzel). There are some pulsejet designs that are at least as anthropomorphic as a lot of modern sculptures that are assumed to represent us. Intake pipes can be in any direction and have any bends you want, if thrust is unimportant to you - you could easily have a pulsejet with two long-sleeved 'arms' and various interesting bends at the 'waist' - pulse combustion images of a Marcel Marceau genre.

Such a sculpture could be 'animated' for viewer participation, too. Now that I have a starting method that works quickly and reliably, there's no reason you couldn't have a small pulsjet sculpture with a little nearby kiosk located at a safe distance that would have a single self-releasing button. Holding the button down would supply spark, propane and starting air, all of which would be incorporated in the design or carefully masked from view. With a starting air supply always available, your engine sculpture doesn't even need to self-sustain to work beautifully for a few moments of amusement. Remember, you saw it here first ...

I have considered jet engines of various kinds as objets d'art for many more years than I've been on the forums, so for me this kind of thinking is nothing new. I essentially consider myself an artist, not a technologist, though I think it impossible to be one without being a little of the other at the same time.

L Cottrill

Re: Proposed Design - Straight Pipe 'Henri' Valveless Pulsej

Posted: Sat Mar 12, 2005 4:57 pm
by Mark
I once thought of a straight pipe capped at one end and having fuel/air injected at the closed end too. Then you could develop pulsejet feedback and have a kind of pulsejet rocket, depending on your political views.
Mark

Re: Proposed Design - Straight Pipe 'Henri' Valveless Pulsej

Posted: Sat Mar 12, 2005 6:20 pm
by Bruno Ogorelec
Mike Everman wrote:I tried the press fit method, granted I did not really try too hard, nor was it the thermal interference you're describing. unfortunately, Bruno, the head plate or plug stays cooler than the chamber wall gets, I think. The heat will relieve the stress you want in the press. Mine went from merely leaky to downright rattling. I had a press and then ran a pipe cutter fore and aft of the washer that was my press-fit bulkhead. I think the CC tube needs to press inside the bulkhead for best chance at it. and add some muffler bond, too.
Well, you have the practical experience. I've seen beautiful crankshafts built up using this method (granted, they used liquid nitrogen!) and they stood up to amazing mechanical loads.

I thought that the cap and the beginning of the chamber would be at more or less the same temperature -- looking at heat patterns on various photographs.

So, a fit too tight even for press fit, which just barely makes it inside when cooled...

Anyway, just one of those nice little ideas that looks better on paper than in practice.

Re: Proposed Design - Straight Pipe 'Henri' Valveless Pulsej

Posted: Sun Mar 13, 2005 1:27 am
by hagent
Thanks Steve for the warm welcome.

Nope... I'm just a newbie to the world of pulse jets. I have not built any yet. So my words don't have much weight to them. I've been thinking about making a type of pulse jet engine for about 10 years now. When I found this forum it really brought back my interest. I hope that I will be able to build it durring the next few months. With a new house and a 3 1/2 year old girl there isn't much time for anything fun... but at least now I have a garage to build stuff in! Next I have to buy a welding setup..

The pulse jet that I will be making first will be from Tesla's idea... I'll be posting more once I start making the intake portion... I have two ideas just have to find out which will be easier to make...

I've been digesting alot of this forum over the last few weeks. You guys are pretty amazing... And it seems you all live in the snow some where :)

I was trying to make a 3D drawing of my picture for Larry but the intake portion wouldn't render very well. It was hard to see what I was trying to get across.

It appears from the drawing you linked me to, thereynst style, has two completly separate parts to the engine.

In my drawing I meant only to show the intake portion of Larry's design so it would only be a one piece tube. The intake would extend past the slit inward flare and towards the pinched area. Maybe a piece of tubing could get inserted and welded in place at an angle?

Bruno your right it would be very simular to the drawing you posted. I do remember seeing this drawing at some point a few weeks ago... Was this design successful?

Also has anyone built a valveless pulse jet that has more thrust than a valved one? Of couse keeping in mind a simular wieght and fuel consumption...

Thanks guys... Hagen

Re: Proposed Design - Straight Pipe 'Henri' Valveless Pulsej

Posted: Sun Mar 13, 2005 3:23 am
by larry cottrill
Well ... lots of great suggestions.

HOWEVER ...

I'm way too early into this to start re-working the basic tube geometry - the existing plan hasn't even been given a fair shot at running yet, in my opinion. Late this afternoon I quickly put together a combined air/fuel tube for Henri, since this concept has worked so well for much more conventional designs. The spout of this tube should cause the air/fuel mixture to cross over the pipe and pour down the opposite side, like the Elektra and FWE originals.

This should at least guarantee good mixing [eliminating that as a variable!] so as to leave nothing to play with but starting fuel and air flows. It should allow a much more methodical approach to be taken, working up gradually from fairly low values. If I ever get it to a good pulsing frequency with maximum heat up at the front end, I'll know I'm just about there. If it runs well under air drive but doesn't sustain, then it will be time to open up the ports significantly.

Pictures later ... no more testing until it warms back up into the 40s, at least, for me.

L Cottrill

Posted: Mon Mar 14, 2005 2:16 am
by hagent
No problem... here is a better drawing of what I tried to post before.

I only drew one intake but there should be two one on each side. Take to much time... in 3D studio.... Image is not to scale...

Good luck!

Hagen

Re: Proposed Design - Straight Pipe 'Henri' Valveless Pulsej

Posted: Tue Mar 15, 2005 1:45 am
by Mark
Larry Cottrill wrote:
Mark wrote:How about a young girl buying some pretzels in Nebraska, next door neighbor to Larry, and selling it for more than the few dollars she paid for the bag of pretzels. I think we should be designing Virgin Mary pulsejets to sell on eBay.
I don't think it would take much to do that by design, but to be valuable it would have to be something that occurs naturally or accidentally, like the shape of heat discoloration somewhere after the engine's first run or some such. You can't manufacture miracles that sell, you have to take them where you find them.
L Cottrill
http://www.usatoday.com/tech/news/2005- ... tzel_x.htm

I can remember an art professor in college in Oregon who brought a gaudy chandelier to class to illustrate the idea of kitsch. A day later the janitor retrieved it from the trash saying surely he didn't want to throw this away. And so the idea of kitsch was introduced to me. Another example was the Pope inside of a seashell for sale at some Florida gift shop. In this case it preys on the sentimentally of the buyer. What could be better than the Pope and a seashell I ask?
What I was half suggesting is that I could design a pulsejet and claim there was some hidden feature in the shape of Mary that produced extra thrust, a resonant secret waiting to be discovered. The other day a patron came in the library and wanted an article out of the newspaper. Apparently he had just bought a house that someone was murdered in. It was two gay men, one who found out the other was fond of someone else. Anyway, this fellow said that he had sprinkled holy water all around the house and was thinking about having a priest come over and bless the house.
So if holy water is just natural and something you can't manufacture, where can I get some, so that my lawn will be greener than the neighbors.
Sorry, but I just find holy water to be water, I don't see it being manufactured or having any miracle cures.
Mark
PS There is nobody more than me who would like to see the world a perfect place, but I can't even begin to touch upon all the sadness that exists.

re: Proposed Design - Straight Pipe 'Henri' Valveless Pulsej

Posted: Tue Mar 15, 2005 7:32 pm
by mk
Mark wrote:[...] What I was half suggesting is that I could design a pulsejet and claim there was some hidden feature in the shape of Mary that produced extra thrust, a resonant secret waiting to be discovered. [...]
It's surely not in the shape of Mary but s.th. like that does exist.
Mark wrote:[...] So if holy water is just natural and something you can't manufacture, where can I get some, so that my lawn will be greener than the neighbors.
Sorry, but I just find holy water to be water, I don't see it being manufactured or having any miracle cures. [...]
IMHO, only natural water can be holy water, originaly because of "God" shouldn't be considered as a grey-haired old man, rather as a feeling (partially) implicted to all plants, animals, humans, things etc. It has surely s.th. to do with spiritualism. Preachers seem to be unecessary then. I'd think they just represent a kind of cristallized support for their stability in an old fashioned way or -- more or less -- an relict from religions representing a power. Then natural water gets its "good aura" in a symbolic way from the preacher, thus the kind of spiritualism becoming reachable for people. Seems to me like a cristallized happening that depends on the actual principle being s.th. like a "rule of matter". Which, thereof, also represents a must.
Briefly, all in all...

re: Proposed Design - Straight Pipe 'Henri' Valveless Pulsej

Posted: Tue Mar 15, 2005 8:19 pm
by Mark
Who can deny some of the previous valveless posts with the twisty augmenters didn't look every bit like a pretzel without the salt crystals attached?
Mark

Re: re: Proposed Design - Straight Pipe 'Henri' Valveless Pu

Posted: Tue Mar 15, 2005 8:37 pm
by mk
Mark wrote:Who can deny some of the previous valveless posts with the twisty augmenters didn't look every bit like a pretzel without the salt crystals attached?
Perhaps they're merely a sweet butter candy pretzel without sugar crystals?

...Only the Bavarians know...

re: Proposed Design - Straight Pipe 'Henri' Valveless Pulsej

Posted: Wed Mar 16, 2005 2:45 am
by Mark
Here's a pretzel without the salt crystals ala Bruno.
Mark
http://www.pulse-jets.com/phpbb2/download.php?id=2950

Another Try at a Fuel / Air Tube

Posted: Fri Apr 01, 2005 8:05 pm
by larry cottrill
Here's my second shot at a starting air tube for Henri - a concentric air / fuel design that should throw across the chamber before it pours to the front.

So far, this hasn't worked any better than the first air tube. However, I may not have experimented enough yet with the delivery pressure on the air supply regulator.

L Cottrill