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Well, don't get me wrong, I am HIGHLY skeptical. I've been inclined to flag the post as off-topic and have resisted, only because airpower seems like a nice guy who probably wouldn't post such "garbage" without some good compelling reason.

This thread is intended for Stirling engine ideas. So, I refrained from commenting or anything else, but if it's OK with the forum owner I'm not going to complain.

Does this have any bearing on Stirling engines? Heat Engines of any kind? I would think not at first glance.

But, as time went on and others commented,..

Atmospheric pressure certainly is a factor in a heat engine.

There are certain elements that distinguish this from a normal siphon. There is this barrel where water falls through a partial low pressure vacuum. There are unusual energy conversions the water is accelerated for a great distance through a long tube. Once in motion, a large volume of flowing fluid is difficult to stop There could potentially be some water hammer effect That is an element of the steam injector, which allows steam from a boiler to be used to drive water back into the same boiler the steam came out of.

I'll suspend judgement until I have some time to build a table top version to play with. But assuming the large version works, does it scale? That is, can the forces involved work without very large volumes of water?

What about hydraulic pressure? The body of water has, at the deeper level, higher pressure, the atmosphere is bearing down on a large surface area the outlet is much, much smaller. So is there any possibility of the inlet pressure under water being higher than the outlet pressure?

Also, there are dozens of videos posted about this thing that begin with some engineer setting up the system so it could be used to water a lotus flower pond.

From other videos, it is also clear that the outlet of the system is actually above the water level of the source.

I'm still not inclined to waste much time on it, but, it is simple and inexpensive to just put one together and see the results. Try to be objective about it and suspend judgement. But it's not a priority project for me at the moment

There is a spring nearby here, where I live in central New York state, at the top of a mountain. People tell me there have been engineers out to investigate. Something about hydraulics. It never stops gushing water. A natural phenomena I'm at a loss to explain. But there is an underground lake. A pocket left by a melting glacier. A situation similar to the raised barrel, so.. maybe.

You have no doubt heard of a ram pump that uses a head of water and the water hammer principle to pump water uphill. They were invented in the 1800's and many were produced and used on farms and such.
I wonder if this unit with the barrel is using the same principle, only with vacuum instead of pressure. Instead of the long tube on the input ,it is on the output. Just a guess here as I haven't seen one in person. The old ram pumps would pump an impressive distance, where this barrel pump appears to barely pump above the input.

And yes , this isn't a sterling engine, but interesting any way. Also connected in a way as many early commercial sterling's were used to pump water.

skypupbob wrote: ↑Tue Feb 15, 2022 9:26 am You have no doubt heard of a ram pump that uses a head of water and the water hammer principle to pump water uphill. They were invented in the 1800's and many were produced and used on farms and such.
I wonder if this unit with the barrel is using the same principle, only with vacuum instead of pressure. Instead of the long tube on the input ,it is on the output. Just a guess here as I haven't seen one in person. The old ram pumps would pump an impressive distance, where this barrel pump appears to barely pump above the input.

There are upright sections at intervals, along the outlet tube. Don't know what purpose they might serve. With a couple dozen videos, I would think, maybe there is an explanation, but I don't have time to go through it all. If I do sometime, and find an explanation of this thing I'll post it, or, maybe someone will.

I've actually been considering trying something similar but using a venturi type "pump" in a flowing stream, just to "siphon" cooling water to an elevated location and back into the stream. Don't know if it will work, but I've already bought the supplies.

Something like:
Since there is a balance of water going up and down, the system is equalized, except the high and low pressure in the venturi will induce a flow.

Not like there is no energy source. But hot water will want to rise, so even if it works in principle, it might not actually work in practice, unless the pressure differential created by the venturi is greater than that created by the temperature differential. In other words, the cooling capacity would likely be very limited.

The idea originated in relation to the compost powered Stirling, as a means of passive water cooling for the engine from a nearby river.

Just had another idea for potentially improving Stirling engine performance dramatically.

There are all kinds of different rubber, silicone, neoprene, even metal, including titanium bellows or expansion joints etc. Similar to these:

https://youtu.be/2zasieOitFg

But preferably rigid, but with flexible joints and heat resistant, not for the piston, but for a displacer.

Leaving enough space Under it for air flow, the displacer/bellows is attached to the bottom hot side heat exchanger.

It is attached to the bottom by rivit-like fasteners that allow the displacer to rise and fall slightly, but hold the displacer bottom down, limiting how far the bottom plate of the displacer can be lifted.

When the bellows is lifted and expanded, air is displaced, pushed, forced downward into the hot space below the displacer, but to one degree or another, the internal volume of the engine is also reduced.

Perhaps there could be a second smaller bellows within the main large bellows, that draws air up through a hole in the bottom of the large bellows to maximize air flow across the inside bottom of the engine, (hot plate heat exchanger)

Could this actually work?

No, the bellows could not expand easily, or at all without drawing in air. Could a channel be open to the atmosphere?

What if the air were drawn in from above the power piston? Through a connecting tube of some kind?

Something similar to a Manson engine, sort of, but not really, but a similar kind of port between the upper piston cylinder to the interior of the bellows, then the rising piston would actually help drive air into the bellows, instead of just wasting that driving force to atmosphere.

Time to redraw/modify the drawing.

I thought I had an idea anyway, but it will need some modification.

In a way I think this is somewhat functionally similar in many ways to how TK Motors diaphragm displacer functions, but the upper portion of the displacer is elastic instead of rigid, but has a similar effect of drawing air down and across the hot heat exchanger when lifted, and also tries, in a way, to reduce internal volume when air is forced downward as the diaphragm is raised, but the volume doesn't actually change, but the channel through which the air must travel is so long and narrow and full of regenerator material, (which impedes air flow), the resulting increase in pressure above the displacer/diaphragm, has a similar bellows-like effect.

But I think this bellows arrangement could potentially have a greater positive effect, along the same lines or in the same direction.

This post has morphed from an idea, into thinking out loud.

The creative process at work.

A rough depiction of a TK Motors type "displacer", (for want of a better term for this diaphragm/bellows thing.


This similarity to a bellows is rather apparent I think.

I've been thinking of a clear Stirling engine with a mechanical butterfly inside that acts as the displacer.

Some videos to maybe help visualize the idea:

https://youtu.be/MKVLSNiY99w

https://youtu.be/osHV5UfANSQ

https://youtu.be/hwmsRqiGF10

https://youtu.be/FnPgrLqfKHw

https://youtu.be/0PHMo13Nh_4

https://youtu.be/SjtOErtcfJ8

https://youtu.be/_T2VxBTnde4

Or a flying dragon displacer might be interesting.

https://youtu.be/six7xWJmuJI

I've been thinking of a clear Stirling engine with a mechanical butterfly inside that acts as the displacer.

This seems pretty close you what you're suggesting:
https://medium.com/@nexusomega/flutter- ... 279cac5982

skyofcolorado wrote: ↑Wed Jun 22, 2022 4:37 pm

I've been thinking of a clear Stirling engine with a mechanical butterfly inside that acts as the displacer.

This seems pretty close you what you're suggesting:
https://medium.com/@nexusomega/flutter- ... 279cac5982

Well, that is an interesting mechanism. But what I had in mind was a literal butterfly automaton flapping it's wings to carry out the basic function of a displacer inside what is otherwise an ordinary LTD type engine.

Something like this, but of course the driving mechanism would likely be on top:

https://youtu.be/BLg2NU3CYIQ

Maybe some clear, nearly invisible fishing line could be used to lift the wings, giving the illusion that the butterfly was powering the engine, which, in a sense, I guess it actually would be.

I was just passing through the local $1 dollar store to pick up a few groceries and noticed, half spilling out of a box on the shelf these colorful tin butterflies:
Though metal, they are actually rather light. I included a 25¢ piece and writing pen in the photo for size comparison.

Metal wings would be a bit heavy but could probably be counterbalanced in one way or another if necessary.

I was working on an idea for a larger size Stirling heat engine that could run off a campfire.

That was actually what got me interested in Stirling engines more than a decade ago, living off grid where at times, my only heat source for cooking and keeping warm and such was a campfire,. But how to run a laptop, phone charger, lights etc. while out camping?

So, this has been something I've been mulling over for years. But today I got another model engine in the mail and had an idea.

What about a suspended fire pit or kind of barbecue grill attached right to the engine? It could be moved around and the fire could be kept enclosed and relatively safe off the ground. Something like this:

Then I was looking for a spoon to stir my morning coffee and had another inspiration, assisted by my new found enthusiasm for using hand sanitizer as a fuel.


https://youtu.be/I-7Huuce46A


Imagine that as a big, maybe cast iron or steel fire pit and sitting around roasting hotdogs or whatever as the Stirling engine provides lights, radio, battery charger, internet or whatever.

The base of the metal fire pit could also be made to conduct some additional heat directly to the engine.

Maybe something like this:


I've been contemplating converting one of those small portable generators to Ringbom.

Just in case it isn't obvious, the cylinder sticking up in the center of the fire pit is the displacer. My own Ringbom-ish design with an air spring in place of a cold side. (If it turns out that idea actually works).

James R. Senft in his "Miniature Ringbom Engines" spends several pages going over the "myriad" of possible configurations.


Essentially the displacer is a kind of independent unit that can be placed anywhere in relation to the power cylinder.

Please, take a look at direction of buildiing Brayton or Ericson cycle engine.
I was needed some time to figure out what's difference between Stirling (a toy) and Ericson (really perspective) cycle.
Really, Ericson can be scaled just like steam or ice engines - just make it bigger, it will make more work.
I published too much messages over forums... Just silence. No one understands how it works and why it is really perspective engine.
It is complicated, have a lot of components... But it really worth to build pressurised Ericson. It has no problems like Stirling,
you can build up big boiler, dead volume is meaningless..