Is Carnot efficiency valid?

[Tom Booth]

3 hours ago, Ghideon said:

Side note while I wait answers to some previous questions:

Have you thought of combining the two types of arrangements? It is probably too mechanically complicated to be useful or realisable but may trigger further ideas: Arrange an even number of Stirling engines in a "Stirling Ring"; hot against hot and cold against cold in a circle. In this thought experiment, what could be the result when applying your ideas?

What would be the heat source?

As I said, heat is your consumable "fuel". So anything like a finite source of heat like a hot metal disk would result in the heat being converted to work output, quickly diminishing. 

I had an odd thing happen recently while experimenting with the setup.

Some heat was building up in the glass dome with the thin insulating lid over it.

The engine had been running for quite a long long time. No recording was being made. Some steam was still getting in under the globe.

The full heat of the steamer continued below the engine.

After maybe an hour of undisturbed continuous operation with the lid on, whens the  lid was finally removed the engine stopped immediately.

This happened several times, but it was necessary to let the engine run for a very long time and for some heat to build up.

Of course, theoretically, (former conventional heat engine theory that is) letting out the heat from under the glass globe should help cool the cold side, let out the "waste heat" relieve the bottle neck and allow the engine to run better.

However the opposite happened, repeatedly. But as I said this would require leaving the engine running undisturbed for very long periods of time, without removing the insulating lid from the top of the glass globe.

It seemed as though the heat building up under, (or within rather) the glass globe assisted the running of the engine.

Removing that heat by venting that space with fresh air caused the engine to stop immediately.

My tentative hypothesis to explain this is that, as observed previously by myself and others, approximately 1/2 the energy to run the engine comes frome atmospheric pressure driving the piston back inward after the expansion stroke.

Under the glass globe, in this case would be the immediate "atmosphere" for the engine.

The only thing not covered by insulation is the top of the piston.

As the reaction was instantaneous, causing the engine to stop immediately I can only see one explanation.

The air under the globe gradually heated up due to the work being applied and possibly some of the steam escaping from under the engine that got through the Aerogel and under the glass globe. That trapped air was also being agitated by the flywheel, much like Joules paddle experiments agitated water, heating it up.

This heat, trapped under the dome was being recirculated to some degree, the excited air molecules above the engine impacting the top of the piston. This likely did not warm up the top cold plate of the engine under the insulation though as that was protected by the Aerogel blanket.

Lifting the lid broke the homeostasis of this recirculating heat input above the engine, causing the engine to stall, but it would always start right back up easily and continue running with the lid off.

This effect takes a very long time to manifest though. Maybe an hour or so of undisturbed operation with the glass globe covered.

Seemed very strange at the time, but I think I understand now what was going on.

Of course the probes should help confirm or refute this. It does not change my hypothesis that the top of the engine under the Aerogel stays cool.

 

[Ghideon]

20 minutes ago, Tom Booth said:

What would be the heat source?

What you proposed:

On 2/7/2023 at 6:25 AM, Tom Booth said:

Sandwich the heat source between two engines

But you have not given any details as far as I can see.

[Tom Booth]

4 hours ago, exchemist said:

The question in the post to which you were responding, of course. This was (just to remind you): "What about the picture that show the experiment at a later state? " 

The diagrams and stuff you posted instead of answering it were irrelevant, because they were trying (as usual) to change the subject, instead of answering the question that had been asked. 

Every time we get close to evidence that does not fit your preconceptions, you duck the issue and hastily veer off, with a smokescreen of more fiddly details of your experimental setup.  

I do not believe you are responding in good faith.

Heat travels in three dimensions, (at least). It does not confine itself to the two dimensional plane where we are debating the "gradient" or lack thereof.

My diagrams illustrate what is happening with the heat dispersal on the vertical axis rather than confining the observation to the horizontal plane seen by the thermal camera.

The working gas being heated by the heat input at the perimeters would be expected to disperse or distribute the heat evenly and uniformly from under the top cold plate.

If the bolts are removed as a source of heat influencing the working fluid above the displacer this will not happen and the entire top plate can then remain cool.

Heat dispersal is not a linear "flow" in one direction, nore is it confined to a plane. The dispersal is outward in all six spatial directions and every direction in between, which of course is why it is so difficult to do these experiments and one must have the utmost vigilance to control the heat flow as it attempts to disperse itself in ALL directions. It is not seeking out, or being drawn to the cold in any way shape or form. The dispersal is completely random in all directions.

I was not evading anything, simply trying to point out what is going on in the vertical plane, which you guys were neglecting that you seem to still not be accounting for or have some unwillingness to take into consideration.

44 minutes ago, Ghideon said:

What you proposed:

But you have not given any details as far as I can see.

This is your round-robin. You tell me the details of your proposed setup. Is your heat source finite, like a hot piece of metal or infinite like an electric heating element?

3 hours ago, studiot said:

 

Yes indeed, yet you have never actively discussed that topic.

Just added a few sentences here and there pouring scorn on the idea.

Just as you poured scorn on my diagram.

 

So let me ask you this.

Suppose you actually had a perfect Carnot engine and and a second engine that was more efficient that the Carnot one.

What would happen if you thermally connected both engines between the same pair of heat sinks with the more efficient one generating a mechanical work output from the available heat. But with the Carnot engine reversed (remember that the fundamental principle of a Carnot engine is that it is fully reversible) so that work generated by the efficient engine was used to drive the reversed Carnot engine to move heat from the cold sink to the hot sink  ?

 

May as well ask what would happen if you tied a leprechaun to a unicorn. The Carnot engine is admittedly just mythology. A recognized impossibility and unfalsifiable. As such it does not even rise to the level of meeting the guidelines of this "speculations" forum.

On 2/8/2023 at 5:45 AM, studiot said:

Well where there are molecules in motion there are also electrons in motion.
Electrons are charged particles in local EM fields and such charged particles in motion emit photonic radiation,

An interesting point in that good electrical conductors are generally also good heat conductors. Good electrical insulators are often also good heat insulators.

In my opinion in conducting experiments with beat it is helpful to view the heat in terms of how an electrical current would be viewed. If you want to control the "flow" of heat, you need to use effective conductors and insulators. Except that I think heat is even more prone to short circuiting.

I would not be necessarily say heat and electricity are the same thing, but there does seem to be some close correlation.

That's why I have speculated that heat is likely something more, or other than simply transfer of kinetic energy.

Infrared light is considered a heat source. So maybe heat is something akin to an extension of the electromagnetic spectrum, or some such thing. However, I'm more interested in what it does and how to control it rather than what it is. It would be nice if we could pin that down though.

Heat, what is it?

Might be a good topic for another thread.

Edited February 9, 2023 by Tom Booth
Typo

[Ghideon]

34 minutes ago, Tom Booth said:

This is your round-robin. You tell me the details of your proposed setup. Is your heat source finite, like a hot piece of metal or infinite like an electric heating element?

It's just a quick idea based on what you posted earlier, nothing worth exploring further if there is no interest.

 

[studiot]

1 hour ago, Tom Booth said:

May as well ask what would happen if you tied a leprechaun to a unicorn. The Carnot engine is admittedly just mythology. A recognized impossibility and unfalsifiable. As such it does not even rise to the level of meeting the guidelines of this "speculations" forum.

 

 

Thank you for admitting that a Carnot Engine is the most efficient conceivable.

 

 

[Tom Booth]

1 hour ago, Ghideon said:

It's just a quick idea based on what you posted earlier, nothing worth exploring further if there is no interest.

 

I didn't say it isn't interesting or potentially worth exploring, just that your question did not specify a heat source.

If the heat source is finite it would be used up. Drained quickly as it went to work output, turning the flywheel and churning the air and making noise etc.

I haven't given the other option much thought.

If heated continually with a heating element...

Let's consider... Heat goes in, gets converted to work output.

If the Carnot flow through theory is correct, the interface between the two cold plates would receive considerable "waste heat".

Is there active cooling there of any kind?

If not, and the Carnot limit is correct, the interface I think, would be flooded with heat and the engines would all cease operation. 

Do you wish to explore the alternative Tom Booth hypothesis as well?

Assuming you do, in that case the engines should continue running, so long as the heat is supplied, as the activity at the cold interface is basically null.

You simply have pairs of engines sharing their heat sources and converting that heat to work output. The cold side being largely uninvolved in the operation except as far as providing a "floor" for the engines "adiabatic bounce" space as I've previously attempted to describe.

Do you understand the concept of "adiabatic bounce"?

I could post some explanatory videos, but as that seems to be frowned upon here, perhaps you can look it up and find them yourself if interested.

Basically, though, if you have adiabatic expansion and contraction this will result in a continuous oscillation, which "ideally" or theoretically would  continue indefinitely. Of course, with loses to friction etc. The oscillation will gradually wind down.

A String engine, in actuality, or in essence, appears to be such an oscillator.

On that note it might also be helpful to look up "Rüchardt experiment". And/or "Rüchardt method".

Edited February 9, 2023 by Tom Booth

[joigus]

2 hours ago, Tom Booth said:

May as well ask what would happen if you tied a leprechaun to a unicorn. The Carnot engine is admittedly just mythology. A recognized impossibility and unfalsifiable. As such it does not even rise to the level of meeting the guidelines of this "speculations" forum.

The concept of a reversible heat engine does not occur in a conceptual vacuum, nor does it occur in a speculative space totally alien to physical reality.

There are many concepts like it in science. Particularly in physics: Inertial frames, frictionless surfaces, point particles... 

The point is: You cannot attain them, but you can get closer and closer to the real thing. You cannot get gradually closer and closer to a leprechaun or a unicorn in any meaningful sense. You can, at best, make a visual mock-up of them.

2 hours ago, Tom Booth said:

That's why I have speculated that heat is likely something more, or other than simply transfer of kinetic energy.

That's not a novel idea. As said:

On 2/8/2023 at 12:05 AM, swansont said:

Heat is not kinetic energy.

Heat is the transfer of energy owing to a temperature difference. This can happen via radiation, conduction or convection.

and certainly not one that affects the conclusions of Carnot's analysis. You've been told:

On 2/4/2023 at 5:51 PM, joigus said:

* If the fluid happened to correspond to a conserved quantity, it wouldn't make much of a difference, TBH. It's a conserved quantity that must go somewhere --for all that Carnot's reasoning is concerned. "Phlogiston" is a place-holder for a concept that was better understood later.

On 2/1/2023 at 3:04 PM, exchemist said:

Yes, I knew vaguely that caloric was supposed to be a sort of nebulous fluid, but I never studied the history of science formally so never had any reason to think much about it. I grouped it mentally with phlogiston and the aether as one of those many dead ends in the development of science. But now I can see what a good (though still wrong) idea it was, and how illuminating it was to people at that time.

Caloric is just a stand-in for something that was only understood after Carnot. But mind you: Understanding a concept better does provide you with a way to, eg, run some preliminary controls on your experiment: Minimise losses by somehow impeding the known mechanisms by which they might happen.

An experiment is not just 'see what happens.' It's more like: Take a theory, think hard about what could affect your experiment. Run some controls. Then operate the whole thing and measure everything that could affect the results according to your theory. Use the data obtained from your previous controls as parameters that affect the workings of your experimental setup. Then run some error analysis. Then report.

Something like that. I'm far from an expert on the experimental side of things, BTW. It's very hard, and I'm not good enough. That's one of many reasons why I don't do them.

I've been scavenging for some material that might be useful to see what on Earth it could be that you're not getting, besides the obvious things. This could --hopefully-- be helpful:

https://academic.oup.com/ijlct/article/11/2/141/2198425#36206861

You would need this, IMO, as you need to understand what sources of entropy you have besides those established in the reversible ideal design.

It would also be worth reading some comments from here:

https://physics.stackexchange.com/questions/78915/efficiency-of-stirling-engine-and-carnots-theorem

Quote

The crucial point is that when the regenerator is included, there is no net heat transfer* into or out of the engine during the processes 2→3, 2→3 and 4→1, 4→1.** The energy that leaves the gaseous working substance during the process 2→32→3 by heat transfer is stored in the regenerator, and that heat is then given back up to the working substance during process 4→1, 4→1. No heat is transferred between the engine and its surroundings during these legs of the cycle.

It's a question about an ideal context, and nobody doubts Carnot's principle there. It's more about recovering Carnot's formula from an ideal --reversible-- Stirling engine. They should agree. And sure enough, they do.

I don't know what else to say. I think I'm about done here.

---------------------

* For an ideal --reversible-- Stirling engine.

** The isochoric legs

PD: Did I forget? Very useful too:

https://www.stirlingengine.com/

[Phi for All]

5 hours ago, Tom Booth said:

Do you wish to explore the alternative Tom Booth hypothesis as well?

!

Moderator Note

No, since this alternative has gone through 17 pages of you avoiding responses that disagree with you and ignoring the science presented. This is a science discussion forum, and we rely on both sides of an argument LISTENING to each other, otherwise you're just soapboxing, and nobody wants to hear THAT.

I wish there was something in your posts that made me think you might have a Eureka! moment, especially given the patient and instructional replies you've gotten, but you've shown that you're going to continue to double down and ignore attempts to teach you something.

Thread closed due to insufficient support, so please don't bring the topic up here again.