Tesla's Ambient Heat Engine revisted

[Tom Booth]

Actually,

A greater ∆T means higher efficiency?

That would mean, if with two engines running on ice, we supply additional heat to the top of one engine and not the other, the engine with the additional heat should run more efficiently, thus converting more heat into work.

Expected result:

The engine supplied with more heat should keep the ice cold better and prevent it from melting longer.

Kind of like upping the voltage supply to your refrigerator to make it cool the ice box faster.

More heat input, more power, more cooling.

And of course, add an external load to one engine and not the other.

The loaded engine does more work, converting more heat into work, the ice gets less heat and melts more slowly. Haven't tried that yet.

Nice to be talking about actual experiments rather than straining over hypothetical cycles anyway.

[Fool]

https://www.engineeringtoolbox.com/cond ... d_428.html

Conductive heat transfer.

conductive_heat_transfer.png (13.84 KiB) Viewed 2395 times

[matt brown]

The experiments you did that I remember were insulating the top cold plate while heating the bottom which is similar, albeit more extreme. I was just over on this thread reading 2020 posts where you had tested ice melt time with running LTD vs static LTD and were going to test 2 LTD simultaneously. That's another long thread that I need to read thru from the start. I found it interesting that static test froze LTD...akin cold going to hot vs hot going to cold. Gotta turn in, more later.

[Fool]

n=1-Tc/The

1-300/400 = 0.25
1-1000/1200 = 0.166

Wider ∆T lower efficiency! How come?

[Tom Booth]

n=1-Tc/The

1-300/400 = 0.25
1-1000/1200 = 0.166

Wider ∆T lower efficiency! How come?

Because, as I've been saying the Carnot efficiency formula is bogus, illogical, irrational nonsense.

Keep going

1-3000/3400 = 11.765%

etc.

Temperature is temperature, an average, not any measure of total quantity of energy, or efficiency.

What's your theory? You tell me.

[Tom Booth]

https://www.engineeringtoolbox.com/cond ... d_428.html

conductive_heat_transfer.png

Is your graphic supposed to prove you can have heat transfer between a metal plate and the air without a measurable temperature difference?

You've certainly selected an appropriate name for yourself.

[Fool]

No. It's just modeling a wall, and given surface temperatures. The constant temperatures outside are standard heat source and sink models. That is similar to all the high and low constant temperature.sources used to model engines.

As Feynman said, "TSOWGI". It's supposed to show how heat flow through a wall boils down to: conduction: temperature difference: thickness: and the temperature profile.

If you were to model the outside and inside physics, you would still arrive at the same measured wall surface temperatures. It's not modeling gas dynamics, it's modeling heat transfer through a wall from measured surface temperature difference. You are using IR cameras and thermocouples to measure surface temperatures. Aren't you? Seemed a simple point, you are a smart guy, so I left it out.

[Tom Booth]

No. It's just modeling a wall, and given surface temperatures. The constant temperatures outside are standard heat source and sink models. That is similar to all the high and low constant temperature.sources used to model engines.

As Feynman said, "TSOWGI". It's supposed to show how heat flow through a wall boils down to: conduction: temperature difference: thickness: and the temperature profile.

If you were to model the outside and inside physics, you would still arrive at the same measured wall surface temperatures. It's not modeling gas dynamics, it's modeling heat transfer through a wall from measured surface temperature difference. You are using IR cameras and thermocouples to measure surface temperatures. Aren't you? Seemed a simple point, you are a smart guy, so I left it out.

Don't know what your driving at exactly, but you've been trying to downplay this IR image:

Compress_20240504_125427_7507.jpg (22.73 KiB) Viewed 2374 times

It shows heat being generated from "work". Work,; mechanical motion, is creating heat from friction at the power piston giving a reading of 75°F at that point, all around the power piston. A hot island on the cold plate.

If the Carnot limit formula/ theory/ calculation were true or real, heat "rejection" to the cold plate should be greater than heat generated by work, don't you think?

You seemed to be suggesting the "modeling of heat transfer through a wall"" somehow explains away the IR image.

Is that your intention?

Or are you just posting random stuff from the engineering toolbox for your own wonderful edification? Presumably you thought it supported your completely nonsensical contention that the cold plate readings is no greater than ambient because heat can somehow be conducted 100% so completely and instantaneously from the cold plate to ambient air that there is no temperature rise at the cold plate at all.

The cold plate metal is magic metal and the air surrounding it is magic. The 80% "waste heat" passing through the cold plate is instantaneously whisked away to the "cold reservoir", is that not your contention?

Just a very very very effective heat exchanger and magical air currents outside the cold plate take all the heat away before it can accumulate even 1° above ambient.

The power cylinder is the same metal. Same air. Why doesn't that 15% (likely much less, flywheel, bearings ets also) heat from friction at the power cylinder dissipate just as quickly in the same way?

[Tom Booth]

...I found it interesting that static test froze LTD...akin cold going to hot vs hot going to cold....

That was rather perplexing.

I think though, it is more a symptom of a lack or "heat flow from hot to cold" vs. boyancy.

The engine is down in an insulated "cold hole".

I had expected, as Tesla suggested, heat would be "compelled" to "flow" into the engine to get to the cold, like a river flowing down hill

That didn't happen.

Instead, the ice, probably starting out about -10°C absorbed heat out of the engine causing it to freeze, maybe bringing the ice up to -8°C or something. Still well below freezing.

But ambient heat did not "automatically" flow in to replace the lost heat keeping the engine warm.

Instead the cold just "pooled" around the engine like a puddle of water and the more buoyant warm air just floated above it.

The insulation was wrapped too high above the top hot plate creating an effective "wall" that held in the "pool" of cold air.

Not exactly the cold going to hot. Rather the engine and ice equalized in temperature, still below freezing. Heat just failed to "flow" down to replace the heat that had been absorbed out of the engine by the ice.

A situation easily remedied by adding fan blades to the flywheel or something to keep the stagnant air moving across the top of the engine. Lower the "wall" of insulation keeping the top plate above the cold strata.

Most of all keep the engine running, because without the displacer moving, the same layering and pooling and buoyancy occurs inside the displacer chamber as well.

Much better if the ice can be put above the engine. Then buoyancy moves the hot air up naturally and the engine has less work to do to keep the heat moving.

Heat doesn't always just naturally "flow" into cold where other factors like buoyancy dominate.

[Stroller]

This is after three hours running on boiling hot water.

That entire engine top has an aluminum cylinder fused together with the aluminum top plate. A stock engine. The power cylinder and cold plate are stock, as they came in the kit, unmodified, not insulated, no acrylic, no aerogel.

Only the sides are insulated. The above image is a clip/screenshot from this video:

https://youtu.be/P11q-BAhvqk

You chop and change which "experiments" you use as examples, and still give no start/end times, start/end water temperatures or volume, claim the water is "boiling hot" for three hours, etc.

This isn't a reasoned discussion, it's a gish gallop.

[Tom Booth]

This is after three hours running on boiling hot water.

That entire engine top has an aluminum cylinder fused together with the aluminum top plate. A stock engine. The power cylinder and cold plate are stock, as they came in the kit, unmodified, not insulated, no acrylic, no aerogel.

Only the sides are insulated. The above image is a clip/screenshot from this video:

https://youtu.be/P11q-BAhvqk

You chop and change which "experiments" you use as examples, and still give no start/end times, start/end water temperatures or volume, claim the water is "boiling hot" for three hours, etc.

This isn't a reasoned discussion, it's a gish gallop.

Works both ways. I'm constantly bombarded by vague innuendo about the validity of some unspecified experiment.

I can only make a best guess what experiment you or fool are referring to with your sweeping dismissals and criticisms.

That is the only image from an experiment I've posted lately that fits the description:

I don't think the majority of the elevated temperature of the power piston and cylinder is due to friction. If it was, the engine would have stopped. I think it's due to them being made of materials which pass heat more readily than the acrylic plastic and aerogel.

I've posted many different experiments over the years I think the only image I've posted recently showing "the elevated temperature of the power piston" was this one:

Compress_20240504_125427_7507.jpg (22.73 KiB) Viewed 2355 times

I'm just pointing out that your dismissive explaining away of the data indicated does not apply. There is no acrylic, plastic, aerogel or insulation of any kind covering the top of the engine. The top plate and power cylinder are all aluminum and fully exposed to the surrounding ambient air.

Pretty obviously the elevated heat signature appearing around the power piston could only be from "work". Mechanical motion. Friction or possibly some localized compression of air at the piston face?

Your explanation that it is from "materials that pass heat more readily" is incorrect. I do not want people to be mislead by your unfounded speculations and baseless opinions.

I presented data from a specific, fully described experiment, including images, video and thermal readings.

You try to dismiss this evidence by bringing in elements of a different unrelated experiment. If there is any "gish gallop" going on its on you

[Fool]

https://m.youtube.com/watch?v=P11q-BAhvqk

You claim the engine was running for three hours, but it is clearly removed from the heat seconds before all measurements are made. Placed on a "cold" ambient table cooling it enough that even when placed back on the water cup, with mist coming off, it stops running. After talking about it for seconds, you restart it. You then measure temperature around the area, barely allowing for instrument stabilization. The first is the table where you set the hot side of the engine. Hmmm

The engines hot plate appears to be acrylic. I wonder how much heat is getting into the engine? Millijoules? You said, somewhere, that acrylic is an insulator, making further claim that heat can't get out. Hmmm

The cold dot in the camera appears to home in on the shaded from room light area. The table top you measure appears to not be shaded. Hmmmmm

"Boiling", I didn't see any boiling. Potentially hot. The engine is running. Yes the water is hot. Boiling no? Hot, 60, 70, 80 °C? Hmmm.

Longer stroke increasing adiabatic cooling? Wouldn't that also increase adiabatic compression, for an identical adiabatic temperature rise reverse stroke? Remember the gas is in the cold space more so, during compression? Hmmm

You may have peaked your own interest doing this experiment. You have inconclusive data. Perhaps even bad data. But certainly nothing worthy of anyone else following you.

Since it appears to challenge 200 years of thermodynamics, you have nothing to stand on. The waving around of both cameras and the engine, is sufficient to suspect a massive influence that we are not seeing.

I still wonder why so little time was spent with the IR camera on the engine?

Stroller, good points.

[Tom Booth]

https://m.youtube.com/watch?v=P11q-BAhvqk

You claim the engine was running for three hours, but it is clearly removed from the heat seconds before all measurements are made. Placed on a "cold" ambient table cooling it enough that even when placed back on the water cup, with mist coming off, it stops running. After talking about it for seconds, you restart it. You then measure temperature around the area, barely allowing for instrument stabilization. The first is the table where you set the hot side of the engine. Hmmm

The engines hot plate appears to be acrylic. I wonder how much heat is getting into the engine? Millijoules? You said, somewhere, that acrylic is an insulator, making further claim that heat can't get out. Hmmm

The cold dot in the camera appears to home in on the shaded from room light area. The table top you measure appears to not be shaded. Hmmmmm

"Boiling", I didn't see any boiling. Potentially hot. The engine is running. Yes the water is hot. Boiling no? Hot, 60, 70, 80 °C? Hmmm.

Longer stroke increasing adiabatic cooling? Wouldn't that also increase adiabatic compression, for an identical adiabatic temperature rise reverse stroke? Remember the gas is in the cold space more so, during compression? Hmmm

You may have peaked your own interest doing this experiment. You have inconclusive data. Perhaps even bad data. But certainly nothing worthy of anyone else following you.

Since it appears to challenge 200 years of thermodynamics, you have nothing to stand on. The waving around of both cameras and the engine, is sufficient to suspect a massive influence that we are not seeing.

I still wonder why so little time was spent with the IR camera on the engine?

Stroller, good points.

You might like to critique this video as well.

https://youtu.be/NtrYSpYD43w

Both are from the same day. Same experiment but a few hours earlier.

After uploading the first video, I thought some explanatory statements might be in order, so made a second video.

True, meddling with the engine did interfere with its operation to some degree.

Yes the bottom plate was acrylic, which no doubt slowed down the heat input in comparison with tests using a metal bottom plate.

There was no attempt at hiding anything or being deceptive or untruthful as you seem to be implying.

I think I said the water was "streaming hot". Obviously not boiling, but it was fresh off the stove after having been brought to a boil.

[Tom Booth]

...
Longer stroke increasing adiabatic cooling? Wouldn't that also increase adiabatic compression, for an identical adiabatic temperature rise reverse stroke? Remember the gas is in the cold space more so, during compression? Hmmm
...

This is your constant refrain, but it is apparently wrong.

The more adiabatic cooling, the more internal energy in the gas is converted to work. The colder the gas gets and the "harder" (more forceful) becomes the subsequent "contraction".

The gas, or working fluid, it seems, requires little work input from atmosphere in its contraction. It is not so much forcefully "compressed" as it contracts on its own accord so that little outside work is actually employed in effecting its compression. Therefore any elevation in temperature is delayed until very close to TDC when the returning piston meets the expanding gas from the new cycles heat influx, rather like a baseball bat meeting a pitched baseball over home plate. The two forces collide propelling the piston outward again.

I know those, like yourself who are steeped in the "ideal gas law" and "kinetic theory" don't believe that gases ever "contract" when cooled or after loosing internal energy. You believe they always have to be forcefully compressed and heat must always be generated during a reduction in gas volume.

It's pretty obvious there is no changing your mind. I've posted links to numerous websites and videos detailing the facts of the matter, that REAL gases do indeed have attractive forces and do indeed "contract" or become reduced in volume when cooled or when there is a loss of internal energy.

If you can't see or accept that, I can't help you. You'll have to discover it on your own or go on steadfast in your opinions.

Personally I don't believe or have fixed opinions about anything I haven't observed myself. Even then I'm skeptical and open to considering alternative explanations.

I've done my own experiments and have seen the results firsthand. You or others should do the same if they think it worth bothering with. No need to take my word for anything.

I provide full disclosure of my methods, procedures, results. Nothing is hidden or withheld so hopefully others will verify the results with their own independent research.

I'm not looking for a "following".

[MikeB]

"Pretty obviously the elevated heat signature appearing around the power piston could only be from "work"."

Why is that?
Could the heat not come from the working fluid?