Jam Jar BCVP

[Mike Everman]

Hey Mike, were did you get the illustration from (it's in German! great!)?

It's from the Squid paper, you can get it from Chris Wertman's site:
http://updates.webchamps.com/pulsejets

[Mark]

Hey Mike, were did you get the illustration from (it's in German! great!)?

It's from the Squid paper, you can get it from Chris Wertman's site:
http://updates.webchamps.com/pulsejets

That site of Chris Wertman's on Project Squid was quite informative. I liked all the variety of things they tried. Fuels, shapes, valves, etc.
Mark

[Bruno Ogorelec]

It's from the Squid paper

How easy it sounds. 'It's from the Squid paper'. But, look back through the years of the forum and you'll see the fabled 'Project Squid' papers mentioned time and again as something of a Holy Grail of pulsejet research. I have lost track of the number of people who have sniffed around for those papers and came away empty-handed.

For the uninitiated -- Project Squid was a US Government project put together at the end of World War II to pool all the existing knowledge of pulsejets and provide new research in the areas where existing knowledge was found to be lacking. Work was done at several top US universities and aerospace companies. It appears to have been coordinated at the Princeton University and most of the documentation is apparently there.

What Chris Wertmann has posted is a part of the fabled hoard. The translation of the 'Gosslau papers' is another part. But, there's much more at Princeton. An entire small library, I think. By now, I expect, most (or all) of it has been un-classified. One can expect it to become classified again, though, if the current paranoia persists.

Of further historic note is the question of where the hell have the hundreds of Ford pulsejet engines disappeared. It is hard to say exactly how many were manufactured in total, but the number must be in the hundreds. Only a few have been fired. Most might still be in storage somewhere dry. I know of only a single one in private hands.

[mk]

How did the person get such a Ford pulse jet?
____________

Today I got an idea while thinking about improving my two Reynst pots made of steel. Both ran pretty good, but just until the mixture of ethanol and air overleans by reaching a critical temperature. First I thought of building a kind of injector ring, something like this in the "unicone engine". But I decided not to do so, because building such a good ring is nearly impossible or would have last some time (at least with my tools at home). Later this evening I ended up with something like that you can see in the drawings.
In my opinion, the advantage of a "double stage bottom" would be a good or rather equal mixing of air and fuel as in the "jam jar-mode" by offering the ability of throttling. Then the first bottom works as a propane vaporizer over nearly the whole bottom area. Furthermore the pot could run until propane is turned off or runs out, not only short times as long as it is cool enough.
...I plan testing it soon.

So, might this work?...Has anybody already tried this? (red: propane; blue: air)

[Bruno Ogorelec]

How did the person get such a Ford pulse jet?

Well, this guy -- Art Arfons -- is a collector of jet engines -- I think he has more than 25. He once held the world land speed record with a jet powered car, the Green Monster, he built himself. His engine was probably purchased as military surplus. In the 1970s it was probably worth very little.

Later this evening I ended up with something like that you can see in the drawings.

In this kind of the engine, unless you are using alcohol, you need to llow the fuel to mix with air. That means that is has to be introduced at the top, so that it is well mixed by the time the vortex reaches the bottom. But, that is theory. You will see for yourself.

[Mike Everman]

I believe, Bruno. I'll try a couple of more things, mk; I was heading in the direction you are with my "cake of pumice" gas distributor at the bottom. Simple bottom feed doesn't even pretend to be close to running, and no matter how slow I introduce it, it defeats the methanol cycle.

[Mark]

In my experience with jam jars, they don't like resonance dampening objects inside the jar. If you had a sea of pumice stones, air flow might ricochet and dampen/baffle the effect, if you have ever picked up a running jam jar, sometimes just a slight jiggle will kill it. Sometimes too much fuel will slosh/deform and it won't even catch enough to sustain. I've put small intrusions up from the bottom for fueling and they don't like that either. It won't feed if you intrude too much on its need for solid uniform reflective surfaces. But nothing is written in stone.
Mark

[mk]

Ok, I don't have to tell any "breake-through" stories about my idea. It seems just to be good-working on paper.
First the pot ran very good, but with the pan and the holes in the bottom I just got a good flamethrower. Even simply running on ethanol wasn't possible...so, just just forget about the idea.

"Lipfeed" just seems to be the most advantegous fuel supplying method at all.

[Rossco]

Hey,

I have had very little do to with these other than a jar that ran for a couple of seconds that i saw when i was at some school thing.

But, as usual, i came up with my own idea for such an engine.

Just for interest sake, i am by no means saying that the thing will run or that i hav even tried it. Let alone how i would invisage starting it?

Any comments?

Rossco

[Mike Everman]

Rossco, I like it. I've been experimenting in not a very systematic way on "snorkels" like you have there. Actually, I've taken a several month break from jam-jars, and I'm going to get back into it. I really want to get a deep snorkel to work, but so far it's just been whooshes.

Marten, did you try the bottom feed on your metal jar? If I discouraged you, you should know that the tries I made had a single input in the middle of the bottom (an inverted propane cannister; I put the working hole in the former base); so yours may work.

[Rossco]

Mike, ive just got a test rig for deep intakes running this very moment!

http://www.pulse-jets.com/phpbb2/viewto ... c&start=30

Its a valveless pulse jet, and ive got a flip over arrangement on the front.
The thing runs on a higher frequency with the intake inwards than it does out. Interesting. Easy to start, which i thought might be a problem.
check it out on the other thread.

Rossco

[Mike Everman]

I don't see anything new there... Are you able to shoot video?

[Rossco]

Im still playing setting up the post atm. Ill stick in the text and go take some pics.

I can take vid, on my camera, but how long, and what do i need to upload it?

Other than ive had another noise complaint and dont dare to run it again just yet.

Rossco

[mk]

Marten, did you try the bottom feed on your metal jar? If I discouraged you, you should know that the tries I made had a single input in the middle of the bottom (an inverted propane cannister; I put the working hole in the former base); so yours may work.

Hello!

1.:
----
I didn't work, Mike, but I didn't improve anything. I read something about a burner, with a mixture of constant combustion and pulsating combustion. At this burner 6 holes for fuel feed at the bottom were used around an air inlet hole (constant airflow through it!). Trying(?) to run this pot without the constant airflow, the mixing was very inadequate (whirls occuring, but too high temperature differences between fuel [propane???] and the athmosphere in the pot). The constant airflow improved this.
The doubble stage bottom might work when the whole pot (and the fuel though as well) is (are) hot. But read the second part of this post. I improved the lipfeed at my small pot; with success.

2.:
---
I tried running my small Reynst pot (81mm/3.2" ID) on propane-butane gas and lip-feed today. After putting a bit ethanol for starting I turned on the propane flow. First the mixture was slightly too rich, because ethanol had to burn off completely, but as ethanol was burned, the pot was regulateable in a wide range, using the original needle valve for regulation. The breathing frequency and noise (not violent in this case; no need of ear protection) also increased, compared to running in jam jar mode. I build the pot only out off black sheet metal, with the cone inside and the conical part at the top. I had neither cooled the pot nor the interior, so there came a lot of sparks out of it.
The photo only shows the general assembly; the pot doesn't run.

I'll improve my bigger pot as soon as I can, too, because it only runs for a few seconds in jam jar mode, then air/fuel-mixture becomes too rich.

[mk]

Hello!

You can see the small pot running on the pictures below; the bigger one is at the right side of the first picture.

I'll still have to do some improvements or at least to provide some cooling, because the pots don't want to run as long as I want them to (however, the bottom of the small pot was glowing).
I also tried a bit with liquid propane/butane delivery, but fuel flow regulation was a headache!