Odd Metal jars

[Mark]

I should say I love this stuff of resonance and feedback when I can ask the right questions. If you are clever, you can get the atoms to do high speed computations and get them to do work for you. Often, it's just hard to figure out what they are saying.
The other day I was thinking a seed, say a maple seed helicopters to the ground, and when it lands, it knows how to talk to the clay, the water and air. For a long time, man has improved plants by talking to them, making more corn and higher yields. One day we might totally design/program a seed from scratch, it's strange to think about. ha
Getting back to odd metal jars, I wonder if there is some way to do a double slit experiment with pulsating combustion. That is, split the resonance and then allow the waves to interfere with each other and perhaps amplify feedback. Tharratt proposed using banks of tiny pulsejets, maybe there is a way to get the atoms to chain react at higher energies, by providing a proper home, with loving parents where they can thrive in the mazes you design for them. ha

PS I can hear some of you saying ...
"Wish it to the cornfield."

[larry cottrill]

On the straight tails I think it is not much different, You pull from a short distance through the intake, or try to pull ambient air into a heated straight duct.

Well ... I think the difference is pretty significant. It can be thought of as a difference in "leverage" or even (stretching, here ;-) "gear ratio". The straight tailpipe not only takes in little cold mass from the surrounding air but also has low mechanical advantage over that "piston" when it wants to get it moving in the rearward direction. The bustle tail takes a much bigger "gulp" of cold air, and then pushes with a high mechanical advantage (almost like a hydraulic "master cylinder" at the chamber nozzle driving a larger "slave cylinder" at the tail end -- see the Lockwood tail cone for the most extreme example!).

The cycle action in the straight tailpipe is like driving your car or bike around with no "low gear" -- the bustle tail action is like driving around with no "high gear". Ha.

Joe -

Ran across something from a 2006 thread that I thought might interest you in relation to the above. This is a comparison of straight and conical tailpipes at three critical points in the cycle: Maximum output, maximum aspiration and best re-pressurization pressure. There are several interesting things to note here, but especially look at the exchanged roles of tailpipe velocity and massflow. Note that the vertical scales are pressure and massflow; scales for density and velocity aren't shown. The blue line is pressure; green is massflow; yellow is velocity (really Mach no., which is always far less than 1.0), and grey is gas density. As always with UFLOW1D, for the massflow and velocity curves, high values represent flow toward the right end.

Note that the engines shown are not good designs, just shapes pulled out of thin air. They are not fully tuned as shown. The velocity node is basically occurring right behind the front chamber cone, but drifts around quite a bit -- one indication of mis-tuning.

Enjoy!

L Cottrill

[PyroJoe]

Thanks Larry. I'm looking through these graphs now, interesting comparison. All in all, they are fairly close at the moment of maximum aspiration.

The mass flow is a fair amount more for the bustled tail at the moment of highest output, but the velocity may have slightly decreased.

[larry cottrill]

Thanks Larry. I'm looking through these graphs now, interesting comparison. All in all, they are fairly close at the moment of maximum aspiration.

Very similar at first glance, but even at this point you can see the cone-tailed engine's bias toward the rear end. The front end action is pretty close except for the reduced velocity. I think the little velocity "peak" in the middle of the intake is pretty interesting, with its accompanying pressure trough. A good spot for carburetion?

The mass flow is a fair amount more for the bustled tail at the moment of highest output, but the velocity may have slightly decreased.

The thing of note here is the huge massflow difference. In power terms, this more than compensates for the reduced velocity in the cone. This illustrates the "gear ratio" I was talking about -- the massflow and velocity at the rear of the chamber (at a slightly earlier time than shown) were very close, but the cone gives the mechanical advantage necessary to move the much larger mass, at the somewhat reduced speed.

Note in all three drawings the higher density (grey curve) 3/4 of the way back in the conical tailpipe. This is an indication of the much improved induction of outside air during aspiration. Also, see how much more of the engine is well pressurized by the conical tail end. We found in the Lady Anne Boleyn design that almost the whole pipe becomes pressurized together at the same time -- all but the two end zones.

Another interesting fact is that the timing is also altered. The "best ejection" and "best aspiration" moments are very similar in time, but look at the timing difference in the moment of "best pressure"! The tail cone is able to pressurize the combustion zone much sooner than the narrow pipe can, even though the mass moved is so much greater. (Of course, it has to be understood that it was up to me to pick the exact "moments" for these shots, so you just have to trust me on where I chose to "call it" for each one ;-)

L Cottrill

[GRIM]

Here is a short vid of the previously mentioned meths n matches start sequence


Notable points might be
The cunning rebar tripod/bipod stand arrangement.
The high tech baling wire n bend the rebar injector fixing and angle adjustment system.

LOL

Turn the volume up, You can hear the small whoosh and then hear it jamjaring on the meths and then stabilize once the propane begins to flow,

I am sure at about 00:26 to 00:30 I can hear the distinct sounds of the meths grumbling and the propane gurgling at the same time, but at different frequencies, Might be the atoms fighting!, can they? , do they ?, maybe there are male and female atoms , and they are not fighting at all, there is only one man who will know the answer to that,

I will put the rest of the vid up on youtube over the weekend

[Mark]

Out of the book Programming the Universe ...
"As it computes, the universe effortlessly spins out intricate and complex structures."To understand how the universe computes - and thus to understand better those complex structures - we must learn how it registers and processes information."
"How hard is it to "speak Atom"? To learn to converse fluently takes a lifetime. I myself am a poor atomic conversationalist, compared with other scientists and quantum-mechanical engineers you will meet in this book. To learn enough to carry on a simple conversation, however, is not hard." ha
"As a professor of quantum-mechanical engineering at MIT, my job is to massage electrons, photons, atoms and molecules into those special states in which they become quantum computers and quantum communication systems. Atoms are tiny but strong, resilient but sensitive. They are easy to talk to (just hit the table and you've talked to billions upon billions of them) but hard to listen to (I bet you can't tell me what the table had to say beyond "thump"). They don't care about you, and they go about their business doing what they have always done. But if you massage them in just the right way, you can charm them. They will compute for you."
Atoms are not alone in their ability to process information. Photons, (particles of light), phonons (particles of sound), quantum dots (artificial atoms), superconducting circuits - all these microscopic systems can register information. And if you speak their language and ask them nicely, they will process that information for you. What language do such systems speak? Like all physical systems, they respond to energy, force, and momentum, to light and sound, to electricity and gravity. In italics > {Physical systems speak a language whose grammar consists of the laws of physics.} Over the last ten years, we have learned this language well enough to talk to atoms - to convince them to perform computations and report the results.

[Mike Everman]

Methanol atoms, propane, gasoline, all speaking the same language to me:
"Burn me! I'll burn you back!"

[Mark]

To me pulsejets and jam jars, and their respective atoms are singing some siren song, some unconscious archetypical story of Homer and the Odyssey. We cling to this love and fascination, but know it cannot last forever. Perhaps the atoms too will remember some things, like two sets of eyes that happened to meet in the sunshine universe, and then pulled away to explore in different directions. And who's to say which was the higher being in this evolving forest of life, those glimmering atoms that sang or me. ha

http://youtube.com/watch?v=u4evZ_57FzM


"And you can sing in the sunshine"
"You'll laugh every da-a-y"
"You'll sing in the sunshine"
"Then be on your way"

"We sang in the sunshine
"You know, we laughed every da-a-y"
"We sang in the sunshine"
"Then she went on her way"

"But Odysseus, who longed to get back to his wife
and reach his home, was being held in a hollow cave
by that mighty nymph Calypso, noble goddess,
who wished to make Odysseus her husband.
But as the seasons came and went, the year arrived
in which, according to what gods had once ordained,
he was to get back to Ithaca, his home—"
http://www.mala.bc.ca/~Johnstoi/homer/A ... dyssey.htm
http://kimtelaswelcome.files.wordpress. ... alypso.jpg
http://www.utexas.edu/courses/introtogr ... 190201.jpg

[GRIM]

Heres the rest of the video, you tube are being slow today,

Shows it running from where the first video stops, then ramp up to “lock in” and running vertical, then whilst running, rotate to horizontal, Then throttle down,

Pulsejetting on a shoestring and great fun,
Even hardened pulsejetters would have fun with one of these.

Of all the fuel atoms, the methanol / ethanol variety, are the most evil ,
Invisible and very hot little suckers ,

They don’t warn you , they just wait silently until you look in the inlet to see if its all gone out, and then, and ONLY then , Do their wild orgy of hot expanding gas thing , ( eyebrow )

link , the sound is better http://www.youtube.com/watch?v=iqknDswOUWA


The technical bods tell me methanol burns cool, “ LIES I TELL YOU, LIES”

[larry cottrill]

Man, that is a very nice run! Cool stuff. The sudden frequency shift is very interesting.

L Cottrill

[GRIM]

Thanks larry
yes, look at the sound on a scope , the waveform gets all distorted when it shifts, and the harmonics become much stronger ,

This weekend, I tried some more “extreme” inlet/tailpipe lengths on this small engine ,

I achieved sustained horizontal and vertical running with a approx 3 meter tailpipe and an approx 200mm long inlet,
I am stating this because, the force of the gasses that are being ejected from the inlet with these lengths are really very strong , and quite cool temperature, one can comfortably hold a finger just inside the inlet flare and feel the oscillating air rushing by ,

The gasses issuing from the exhaust are still quite hot even after their long journey, enough temperature to burn grass or paper, and of course the CC gets very hot (dull red in daylight)

Now when I say “sustained running“ it’s a low frequency chuffing , not at all loud,
But pulsating and just strange,

The cc hisses from the injector hole, this suggests to me that some compression is going on,

Probably useless information, but fun. (For me , but then I am easily pleased)

[PyroJoe]

Absolutely love that engine. Starts Jam Jarry surpass ordinary draft, all the way up to pulse jet glowing CC. Great work!

[larry cottrill]

Thanks larry
yes, look at the sound on a scope , the waveform gets all distorted when it shifts, and the harmonics become much stronger

I'll bet you're getting the location of the pressure antinode (velocity node) to change positions -- possibly, sometimes at the front plate of the chamber, sometimes at or near the rear plate. Just speculation, of course.

L Cottrill

[GRIM]

Here are a couple of drawings, Just in case anyone feels the need for a new toy,

This will run on very low gas pressure, (a tonic for the winter propane pressure blues) ,
It will never fly; I doubt the thrust produced is measurable; it’s just an easy to build; fun noise and heat maker,

As long as the engine is made close to the dimensions shown it should perform in a similar manner to the original,
The inlet and exhaust lengths are very tolerant, start with an exhaust of about 2 meters and inlet as shown , I have a small slip coupling and hose clip at the 1 meter mark ,and I just add tube as I feel the need,

It is likely that the inlet and exhaust tube diameters are also not critical, but I cannot guarantee this as I have not tried with other tube diameters,

A flare on the inlet really helps; flaring the exhaust doesn’t seem to make any difference,

The injector is another issue,
If the injector is not made exactly to the drawing, it is likely the engine wont run at all, it really is that sensitive, (there may be other injectors that work better, I have just not found one yet)

With the gas valve cracked open as low as it will go, (or hopefully a needle valve is available) 3 separate small angled flames should issue from the injector see vid ,

Slight injector mount angle and protrusion changes make big differences, angles slightly greater than 45 degrees from the inlet are generally good, and “just” inside the chamber seems to work best ,

The hole for the injector should be drilled the same size as the injector tube, a reasonably close fit is important, use exhaust paste if necessary,

Once the 3 flame injector is good, the engine will run,
But there are tricks to the start sequence,

The easiest is to light the injector outside the engine , with the smallest practical and sustainable flame and push this into the cc through the close fitting hole , and then gently increase the gas , I recommend this to begin with , it is easier to find the best injector position this way,

Another way is with the meths as shown in the vid,

Very long matches , or short matches fixed to the end of a piece of wire, pushed down the inlet also work, but it is critical to get the timing just right, and you use up lots of matches ,

All methods require an air out, (blow down the exhaust),

Have fun, don’t forget to feed it some straw, or dry grass, or lolly stick, whilst running at a high idle, Faaaascinating to hear it rev up.

[GRIM]

A little vid ,