Carnot reveal for Tom

[matt brown]

Why illustrate or represent one displacer as two pistons? Or was that a typo, or maybe you meant the lower two pistons each represent a displacer?

Yes, the 2 lower single-acting pistons, B and C, represent 1 displacer. I depicted them this way for clarity of isobaric blow during 2nd half of voodoo cycle vs typical gamma cycle with 2 isochoric blows.

I thought that the typical gamma graphic you posted would be unconvincing, like merely listing PVTm values would fail to convince most guys. So, the trick here was making graphic similar enough so as not to confuse everyone while making it distinct enough to convey a difference. No consideration was given to mechanical means which would be more complex than typical gamma.

[Tom Booth]

Yes, the 2 lower single-acting pistons, B and C, represent 1 displacer.

Thanks,

I'm still having some issue with versioning. In the first illustration on this thread:

Carnot reveal via voodoo.png (19.51 KiB) Viewed 14114 times

The combined total hot and cold displacer chamber volume appears to grow and shrink. (Voodoo cycle 3:0 -> 0:6)

This volume change seems to have disappeared in subsequent versions.

Needless to say, a displacer chamber that changes volume presents or would present, some conceptual as well as engineering challenges.

[matt brown]

I'm still having some issue with versioning. In the first illustration on this thread:

The combined total hot and cold displacer chamber volume appears to grow and shrink. (Voodoo cycle 3:0 -> 0:6)

This volume change seems to have disappeared in subsequent versions.

Forget that first graphic which I posted by error (too much junk on my desktop). You know the downside here...timeout and edit limits.

[matt brown]

Both of the first 2 graphics (the posts themselves) relate the same voodoo cycle, but as you see, how they're depicted can warp reception. The problem is that they're both mere freeze frames and that the motion is implied between these figures. In the first (original) graphic, I depicted all the volumes independent. In the second graphic, I depicted both gamma and voodoo with exactly the same first 2 figures, but this forced voodoo depiction to merge volumes later.

I've spent years (decades) doodling like this and even I struggle at times to find the best way to describe this kind of stuff. I really need to branch out into animation and plan to give gimp a try. Meanwhile, my preferred depiction is simple timeline, but this lacks the eye candy of sequence figures.

The other challenge is when, as here, the scheme is half-baked...in that this is only the thermo theory part, not an actual engine which would be far more complex (more cylinders/displacers) or involve compromise (out-of-phase, whatever).

[Tom Booth]

Well, the first illustration would certainly IMO, not be impossible, using some phasing crank angle or cams or some such thing, challenging but not impossible.

I'm mostly just interested in specifically, at least one concrete example of what leads you to the conclusion that a cold side or sink, is not required.

I started speculating on that back around 2010 and posted about it here:

viewtopic.php?f=1&t=478

Then more recently, experiments appear to add some weight to the possibility.

Your approach is different and my intention is not to criticize or debunk but understand.

My theory is based mostly on the idea, simply, that "when a gas expands and is (simultaneously) made to do work such as driving a piston in an engine" the result is a pronounced drop in temperature, potentially, all the way down to cryogenic/liquid air temperature in a single stroke, before the gas leaves the cylinder. This is from the science of gas liquefaction, such as the Claude method of air liquefaction:

Resize_20230704_063717_7366.jpg (73.22 KiB) Viewed 14086 times

Source: https://www.google.com/amp/s/www.geeksf ... gases/amp/

Adiabatic expansion involving mechanical work: When a gas undergoes adiabatic expansion involving mechanical work, some of its kinetic energy is lost, and the temperature drops.

Note in particular the "cylinder" with its piston.

The air or gas is rapidly cooled to a liquid state via the conversion of heat to work by first compressing the gas to a very high pressure, then letting it expand driving an engine. Often the work output from the engine is used to drive the compressor in a "bootstrap" configuration.

This is much more effective in terms of the extreme cryogenic cold produced and results in much more rapid cooling than the Lind or other processes such as the compression/expansion cycle in ordinary refrigeration.

Of course a small model Stirling engine does not generally involve extremely high compression, but IMO the general process of compression and expansion with work output parallels the Claude process for generating liquid air, but we aren't talking about a Stirling engine dropping to minus 300° F on the cold side, just somewhere back down around ambient so that supplemental external cooling is not required. That does not seem unreasonable to me.

[Nobody]

Matt,

I find it interesting that people that are attempting to break the laws of physics, to make a perpetual motion machine, or any other fracture of any of those laws, either don't realize they are attempting to break a law, nor attempting perpetual motion. They seem to think it will have little effect on physics. They also, typically, pronounce their ability to do so long before producing any working machine. The difficulties are usually written off by stating that they are difficulties and can be solved. They then seem to want help from others to overcome those difficulties.They also leave out important theoretical information as to how this is accomplished.

You have not provided any PV or TS diagram for your Voodoo cycle. Tom has not provided any for his hot potato engine. It looks as if you are basically trying to cut the last step off from the gamma cycle with an isobaric process. From step #3 back to step #1 the volume goes from 9 to 6, and it is also calling for isobaric regeneration. Isobaric processes require both heat transfer and work. The air in the working piston volume would be pushed into the cold volume and will need work into it and heat removed from it to do so. Both values will be greater than for the equivalent gamma regeneration and isothermal compression. Visualize, or draw a PV diagram for your cycle.

200 years, and counting, of trying to prove Carnot wrong, and still no working models. Thousands have tried and are still trying. Thousands, and counting, have failed. Yes, I'm one of them. I now can see why they fail. Good hunting.

An engine running without heat rejection would allow an over unity machine to be built. That violates the law of conservation of energy, and all of physics would be wrong. All...

Tom,
The atmospheric pressure will help push a piston back in during compression, however it opposes it during expansion. The two are equal and opposite, hence can be ignored. They add to zero net work. True of buffer pressure too.

The crossover effect does reduce the need for mv, flywheel, piston mass, to carry the engine through compression and expansion. I.e., allows smaller masses. Provides acceleration in both directions. But it doesn't add any net energy production out of the engine.

[VincentG]

An engine running without heat rejection would allow an over unity machine to be built. That violates the law of conservation of energy, and all of physics would be wrong. All...

Glad you entered the chat. I don't think anyone is claiming zero heat rejection or perpetual motion, either of those would be creating energy from nothing. We are surrounded by energy that can be harnessed by these machines, and used in part to create a cold hole.

The argument is simply to show that internal cooling can occur when traded for work output via heat pump effect.

I think the takeaway from Matt's voodoo cycle is this;
If we can agree that a higher compression ratio(adding heat from work) improves engine efficiency, then it stands to reason that a higher expansion ratio(removing heat from work) will also serve to boost efficiency. Voodoo loses power output because all cooling is handled through work. Obviously a balance must be reached for a net positive.

[Tom Booth]

Matt,

I find it interesting that people that are attempting to break the laws of physics, to make a perpetual motion machine, or any other fracture of any of those laws, either don't realize they are attempting to break a law, nor attempting perpetual motion. They seem to think it will have little effect on physics. They also, typically, pronounce their ability to do so long before producing any working machine. The difficulties are usually written off by stating that they are difficulties and can be solved. They then seem to want help from others to overcome those difficulties.They also leave out important theoretical information as to how this is accomplished.

You have not provided any PV or TS diagram for your Voodoo cycle. Tom has not provided any for his hot potato engine. It looks as if you are basically trying to cut the last step off from the gamma cycle with an isobaric process. From step #3 back to step #1 the volume goes from 9 to 6, and it is also calling for isobaric regeneration. Isobaric processes require both heat transfer and work. The air in the working piston volume would be pushed into the cold volume and will need work into it and heat removed from it to do so. Both values will be greater than for the equivalent gamma regeneration and isothermal compression. Visualize, or draw a PV diagram for your cycle.

200 years, and counting, of trying to prove Carnot wrong, and still no working models. Thousands have tried and are still trying. Thousands, and counting, have failed. Yes, I'm one of them. I now can see why they fail. Good hunting.

An engine running without heat rejection would allow an over unity machine to be built. That violates the law of conservation of energy, and all of physics would be wrong. All...

Tom,
The atmospheric pressure will help push a piston back in during compression, however it opposes it during expansion. The two are equal and opposite, hence can be ignored. They add to zero net work. True of buffer pressure too.

The crossover effect does reduce the need for mv, flywheel, piston mass, to carry the engine through compression and expansion. I.e., allows smaller masses. Provides acceleration in both directions. But it doesn't add any net energy production out of the engine.

Welcome back, assuming you are the same "Nobody" here previously: viewtopic.php?f=1&t=918&start=465#p16379

[Tom Booth]

An engine running without heat rejection would allow an over unity machine to be built. That violates the law of conservation of energy, and all of physics would be wrong. All...

Glad you entered the chat. I don't think anyone is claiming zero heat rejection or perpetual motion, either of those would be creating energy from nothing. We are surrounded by energy that can be harnessed by these machines, and used in part to create a cold hole. ...

I'm curious, does the "drinking bird" novelty toy operate "without heat rejection"?

[VincentG]

The drinking bird will not operate without heat rejection Tom and is a great example of an ambient heat engine, and for all intents and purposes IS perpetual motion.

Its also a great example of using the infinite nature of ambient energy to provide cooling. If the birds head were insulated, no evaporative(read-expansive) cooling would take place and the bird would stop.

[Tom Booth]

The drinking bird will not operate without heat rejection Tom and is a great example of an ambient heat engine, and for all intents and purposes IS perpetual motion.

Its also a great example of using the infinite nature of ambient energy to provide cooling. If the birds head were insulated, no evaporative(read-expansive) cooling would take place and the bird would stop.

Just out of curiosity, where, when and how does the drinking bird "reject" heat.

Evaporation does not result in heat, as such, leaving the birds head. Evaporation is a cooling process that involves energy being used to change phase not transfer heat.

This is the same sort of issue where an engine does work resulting in a temperature drop. The HEAT (at least some of it) goes out as WORK. I don't think we can consider either evaporation or work output as forms of "heat rejection".

[VincentG]

It's good that the discussion has boiled down to this simple example.

The bird at rest is fully heat soaked.
After the beak is wet, the water evaporates, and in doing so takes heat from the glass tube away with it, starting the process.

Do we not agree that heat is rejected to the phase change of water(or alcohol)?

[Bumpkin]

“Nobody’ wrote, “An engine running without heat rejection would allow an over unity machine to be built. That violates the law of conservation of energy, and all of physics would be wrong.”

Bullshit. Twice over.

There’s no “over-unity” represented in converting heat to power. A “cold-hole” engine (if at all possible) would simply convert heat to power and leave behind “cold” exhaust. The energy balance remains the same.

Bumpkin

[Tom Booth]

...
After the beak is wet, the water evaporates, and in doing so takes heat from the glass tube away with it, ...

Well, that is like saying I get in a car and drive away, as if this THING or substance called "heat" gets associated with the water vapor and drifts off somewhere.

Generally "heat" is something measurable with a thermometer. If the water has "taken" heat then it's temperature should measurably increase.

Is the water vapor leaving the birds head warm or hot like steam? Is the air surrounding the birds head warmer?

This source says:

Energy is needed for the phase of matter to change.

..., when a substance vaporizes, it needs an extra amount of heat energy. This is known as latent heat of vaporization.

The temperature remains constant because all of the heat energy supplied is used for the change of phase of matter. Temperature of liquid does not change during evaporation because the heat taken by the water from the surrounding is used to convert the state of water from liquid to gas by increasing kinetic energy among the molecules and this kinetic energy increases the intermolecular space. Thus changing the state of water. Therefore there is no rise in the temperature of the water.

In the case of a heat engine converting heat into work we have a similar situation, but instead of increasing intermolecular space, a different transformation takes place, nevertheless, what we have is a kind of energy transformation from heat proper into something else that is no longer detectable or measurable as heat.

What does it mean to say that a heat engine "rejects" heat? I'm pretty sure that does not include work output. What about latent heat of vaporization?

Heat is defined as "Heat is the transfer of thermal energy from one physical system to another system or from one region in a physical system to another region."

Is evaporation a "transfer of thermal energy"?

I would characterize it as an energy conversion. Heat disappears. In its place there is "an increase in molecular space".

Not trying to be nit picking or obtuse I just think it is important to keep in mind the distinction between heat as actual heat transfer that can be measured as an elevation in temperature and heat conversion into some other form of energy.

Or maybe it isn't important.

Can heat "rejection" take place in some way other than an actual heat transfer? I did not invent the terminology.

[Tom Booth]

Source of quote in previous post:

https://byjus.com/question-answer/does- ... aporation/

An engine running without heat rejection would allow an over unity machine to be built. That violates the law of conservation of energy, and all of physics would be wrong. All...

... I don't think anyone is claiming zero heat rejection or perpetual motion, either of those would be creating energy from nothing.....
.

"Nobody", IMO is basically right, speaking for myself anyway, though I don't consider myself to be advocating any particular point of view or making any "claim" I am openly researching, investigating or "looking into" in an unbiased, unprejudiced way "An engine running without heat rejection", but this is a measurable, repeatable observation of a reality not any unsupported "claim".

For example, aside from semantics or rationalizations or interpretations of the meanings and usage of words, using a thermometer and taking a measurement, no "HEAT" can be found leaving the drinking birds head, only a drop in temperature.

Under certain, not all that uncommon circumstances I've found the same thing on the "cold side" of a quite ordinary Stirling engine. No "HEAT" as such departing the scene, as evidenced by a general rise in temperature at or around the supposed point of departure where this heat "rejection" is supposedly taking place.

I don't agree with "Nobody" that this violates conservation of energy. Actually it demonstrates conservation of energy.

If heat is a form of energy it cannot be "rejected" as "waste heat" while also being converted to and going out as "work".

I don't think ALL science is wrong or should be or would be overturned, but I certainly think that the so-called Carnot Limit" as generally interpreted is a demonstrable fallacy.

The Carnot Limit does have some basis. It represents the temperature difference on the absolute scale, but that is all.

If the Carnot Limit said you can't operate a heat engine without a temperature difference or without some heat loss I would be more or less accepting of that, but that is not what it says, it says that If I use 100,000 joules of heat to boil water then only, at best, maybe 20,000 joules of that are available to run my heat engine.

I think this is a preposterous, ludicrous and unjustifiable transposition of a simple ratio (the ∆T) in a way that is not supported by any empirical evidence. It can be easily debunked by measuring the temperature of the "sink".

If there were no temperature rise, maybe we could say that the heat rejection is minute and so difficult to detect, but in actuality, like with the drinking bird, experimentally, it is sometimes possible to measure a temperature fall or "refrigeration" effect.

With the drinking bird the question of 'where did the heat go?' is fairly obvious and traceable, attributable to evaporation, and not all that controversial, but in the case of a Stirling type heat engine there is this prejudice against any efficiency of any heat conversion to work output above the arbitrary "Carnot Limit" which is not and has not been supported by any experimental evidence in the course of the past two centuries.