Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

[Tom Booth]

... when the steam piston is pushed in and the pressure increases, the moisture at the higher pressure becomes at a higher temperature. Steam, on the other hand, is mostly formed when the pressure drops and the steam condenses in the upper part. This is good and bad qualities of the engine. In a cold place, however, it condenses, the lower the pressure, the better. It condenses at a lower presure at a lower temperature... Thus, a larger delta-T can be created.

One thing to keep in mind, possibly, if this engine is anything like a real Stirling engine;

A theoretical or "ideal" PV diagram or cycle usually depicts the maximum volume as being also the lowest pressure. However, actual measurements taken in a real engine show the lowest pressure as taking place during the return stroke:


Theoretical:

Resize_20221115_092020_0426.jpg (28 KiB) Viewed 8676 times

Real:

iMarkup_20221108_055032.jpg (122.75 KiB) Viewed 8676 times

Especially under load.

So, if the rice engine behaves similarly, then it may be that the pressure continues to drop even as the piston is being drawn inward while volume is decreasing

I imagine adiabatic expansion results in cooling which initiates condensation and contraction which once started continues for a time, even while the volume decreases.

[Tom Booth]

.. I'm on vacation over seas atm, but I'm taking some time to work on it. I've got a mill, lathe and a few engineers from Siemens here interested in helping me get a piston model running. So I'll probably have some great insights to post to my channel next week.

Just subscribed to make sure I don't miss anything.

Still looking forward to seeing those explosions!

Trying to be patient, but it's been over a month, not that I'm anyone to complain, I think I proposed at least two experiments and/or "rice engine" designs/modifications I still need to follow through on.

I guess I keep just proposing ides hoping someone else will try it and save me the time and trouble.

I think I need to just treat my workshop like a job, go there and do something. Difficult, to actually arrange the time though.

Anyway, looking forward to any updates from anyone on this thread.

Recently I've been looking deeper into the "Zero motor".invented by John Gamgee.

I don't consider anhydrous ammonia anything anyone should fool around with, but was just wondering what a bit of household ammonia (mostly water) might do for the rice engine. An absorption refrigerator also uses hydrogen gas. To maintain partial pressure in the system and I guess, keep it from imploding.

About Gamgee and his zero Motor, I came across an old Naval document, just a routine report detailing activities of the day that reads:

Report of Passed Assistant Engineer W. A. Windsor, of U.S.S. Standish, August 29, 1881.]

At the Washington yard, the first place visited by the vessel, in the department of steam engineering an excellent opportunity was presented for the cadets to study the construction of the cylindrical boilers, in all stages of construction, being made for the U.S.S. Enterprise. The laying off of the plates, drilling and punching of the holes, flanging, riveting, splitting, and calking of seams, and drilling of holes in the tube-sheets were witnessed and explained to the cadets.

The manner of strengthening the cylindrical furnace tubes of these boilers with the Adamson flanged joint, was particularly noticed. The fitting up of a Waddell equilibrium steam-valve was explained. In this department the cadets inspected the ammonia gas-engine of Professor Gamgee. This machine is a compound rotary engine, and is intended to be operated by gas generated from pure anhydrous ammonia from the heat of natural surroundings, whether of air or water. * * *

Not sure if the "***" indicates redacted material.

https://www.history.navy.mil/research/l ... ibben.html

The citation is from way way down on the page somewhere, search for a key work to locate it more quickly.

This is an official US Navy document proving a Gamgee Zero motor of some sort existed and was routinely displayed to cadets.

That's not to say that it actually performed as intended, but it was studied for some months and approved by president Garfield who at the time of that report was lingering on his death bed in the hospital.

[Tom Booth]

Uploaded today:

https://youtu.be/Ia4dN0fem6s

[tibsim]

I can't think about this very much now because I'm working, but in first this looks HTD steam engine.

[tibsim]

This is maybe better (more in TAHSE configuration)the pressure conditions are more ideal:

Although the resonator is also thick in the first drawing...

[tibsim]

And maybe more better with diaphragm:

[tibsim]

I forgot the hole...
Although it's more fluidyne or putt-putt, not thermoacoustic..

[Tom Booth]

Seems similar to this in principle:

viewtopic.php?f=1&t=5413

But without check valves.

[Tom Booth]

This is maybe better (more in TAHSE configuration)the pressure conditions are more ideal:

Although the resonator is also thick in the first drawing...

I'd like to see someone try this idea, even if I never get around to it.

I got as far as ordering a small bottle of ferrofluid. Now sitting on the shelf in my shop, along with a line up of other projects that need to be completed.

viewtopic.php?f=1&t=5477#p17978

[Tom Booth]

And again today.

https://youtu.be/VcebI0ez0Js


300,000 subscribers to that channel

[Tom Booth]

The massive amount of steam wafting up out of that gravel, even after a few minutes away from the heat is telling.

Resize_20221210_200315_5542.jpg (136 KiB) Viewed 8446 times

So much for COLD rocks I think. Looks like steaming hot rocks like in a sauna, but I'm not entirely sure what to conclude from that.

Maybe the steam is only coming from the rocks that were closest to the bottom. Nevertheless at least some of the gravel was holding a tremendous amount of heat and moisture. The rapidity of the formation of a cloud of steam when dumped out and exposed to the cool air is significant I think (assuming the air in the room was cooler than inside the can)

I'm thinking a similar release of steam from the gravel takes place inside the can with adiabatic cooling.

Maybe not, but IMO that lends a bit of weight to the rapid evaporation-condensation cycle theory.

[Tom Booth]

That is where my opinions/conclusions diverge from the mainstream, general "known" conventional physics apparent dominant majority as represented in this article:

https://eandt.theiet.org/content/articl ... president/

John Gamgee is essentially mocked as a nincompoop who knew nothing on the subject.

The fatal flaw in Gamgee’s plan was failing to understand that condensing ammonia vapour would require cooling it to well below ambient temperature, to -33°C, something which would require more energy than was obtained from the piston stroke.

...Perhaps he misunderstood the operation of a water-sourced heat pump, or simply couldn’t accept the laws of thermodynamics,

Look up his article "On Artificial Refrigeration" and read it. Then come back and tell me this guy (John Gamgee), was ignorant on the subject of refrigeration and thermodynamics. From the section on his "Thermo-Glacial Engine" therein, it is clear that he had a working, very effective ice making machine based on the same principles as his zero-motor.

What the writer of the above referenced article (and many others from different authors) fails to take into consideration is his own ignorance in regard to the behavior of gases or liquids at or near phase change when molecular forces of attraction and repulsion dominate, the weird behavior of a so-called "saturated liquid" which applies to nearly every refrigeration system, where liquids condense and boil in a vacuum or under pressure outside "ideal" parameters.

I bring this up again because in this "Rice Engine" we have what appears to be a nearly identical process of boiling and condensation taking place within a heat engine.

Gamgee admirably and mater of factually outlines the principles involved in his article "On Artificial Refrigeration".

When a gas (or vapor from a boiling liquid) expands and does work in an engine it will spontaneously cool and condense back into a liquid due to the expenditure of energy.

That all this might actually take place in a simple tin can full of gravel with a balloon stretched over the top, and only a tea candle as an energy source is...

Choose the adjective: Fantastic Incredible, Astonishing, Awesome, Extraordinary, Phenomenal, Stunning, Mind-blowing, ...

[Tom Booth]

Yet another?

This video is quite recent, but apparently predates the start of this thread by at least a few days.


https://youtu.be/KSTMizeNzaE

Interesting how it seems to run better after being removed from the heat. (Rather than letting out steam through a pin hole), looks like the pressure begins to equalize by cooling down.

Too much heat and too much internal pressure for atmospheric pressure to effect the return stroke? It seems a pressure balance is more important than high heat.

[Tom Booth]

Still at it:

https://youtu.be/BvaTNI8RdNM


Using a ceramic container on top is interesting. I was interested to see if that would actually work, as ceramic does not generally conduct heat very well at all.

So, the gravel would only dissipate heat by conduction with difficulty.

In other words, the ceramic container would prevent cooling of the gravel by conducting heat away to a (potentially water cooled) external "sink".

Using acrylic or PVC pipe would retain even more heat, or rather prevent heat loss to any potential sink (such as the surrounding air).

In this video, the engine did not run long and the gravel has a lot of heat capacity so it is not conclusive IMO. But, the fact that the engine would run at all without a good metal heat conductor to dissipate heat tends to support the theory that cooling/condensation of the steam is a result of work output rather than conducting heat to the presumably cold or cool medium (rice gravel or whatever.

The engine seemed to slow to a stop under load.

It also, again, seemed like the engine ran better when not being directly heated, which seems a little strange.

I'm thinking that might be less of a problem in a sealed engine with a buffer space or air spring rather than atmosphere.

My reason for thinking so is that atmospheric pressure is what powers the return (inward) motion or "contraction".

So the inner pressure cannot exceed atmospheric pressure.

A sealed engine would allow the pressure of the buffer space to climb along with the inner engine pressure so as to maintain a balance at higher power levels.

Maybe.


Well, well, well. I missed this one

Methanol

https://youtu.be/ugk819GQ6Z0

[Tom Booth]

And, well ..

https://youtu.be/KrUvZcBrpZ8

https://youtu.be/UHm_NIoomzs


I think maybe we need to come up with something other than "strange engine" to call this.