Self-Running Ambient Heat Engine

[Tom Booth]

Hello Tom,

Regarding your Stirling engine work. Please remember that energy is required to compress a gas.

CO2 will provide energy far above any mechanically compressed gas.

Is not CO2 used as a refrigerant a mechanically compressed gas as well?

Relatively warm ambient air is a given, it's all around us. Compressing some of it turns the low-grade heat into concentrated high-grade heat which can be used to run a heat engine to in turn run a compressor to compress more air and extract additional heat. Further, the heat extraction process results in a by-product of cold air which can be used to widen the temperature difference to make more of the existing heat available for use.

Also in a Stirling Heat Engine heat which is not used (not converted to electricity or some form of energy other than heat) can be reclaimed or reused by means of a regenerator.

It seems to me that if anything, there would be an excess of heat energy, some of which would need to be thrown off or wasted so as to maintain the cold heat-sink.

I can see no reason why a Stirling Engine, even a small model, could not run a small air compressor, (something on the order of a hand held fire piston) to extract low-grade heat from the air making it high-grade for utilization. Released back to atmosphere such compressed and cooled air would become extremely cold upon expansion. Utilized, this cold air would make more of the existing ambient heat available for use.

This seems so simple to me in principle that I really can't understand why I haven't been able to find any examples of anyone anywhere who has even tried it.

I think it would take a relatively modest sum to build such an engine. At least a small prototype, but it would take a clear understanding of the principles involved. The heat would need to be carefully channeled and directed, concentrated here, dispersed there, like electricity flowing through wires there could be no "short circuit" or absence of insulation at critical points. I think it would have been virtually impossible for Tesla to build such a device in his own time. Cast Iron is a very poor heat insulator but I suspect it was the only material available for engine building at the time.

A fire-piston is generally made out of wood, a very good container for compressing air and retaining all the heat. From what I've seen the metal fire-pistons are much less reliable and difficult to get lit. They need a really good whack. The wooden or plastic ones seem much more reliable as they don't conduct heat so the heat is retained in the air as it is compressed and so don't require as much effort to get lit.

[Tom Booth]

It's been quite a long while but I'm at the point in my research regarding Tesla's "Self Acting Engine" that it seems there is no choice but for me to build it and see if it works or not.

I think there is enough of a chance that it will work that I've sunk several thousand dollars into buying equipment. Drill press and metal lathe etc.

I'm not doing this to patent anything or get rich if it happens to work, I just feel that if there is any chance that Tesla was right, It just has to be done and I don't know of any other efforts to build any such engine as Tesla described since Tesla himself wrote about it.

I know it is supposed to be contrary to the second law of thermodynamics and that if it were possible someone would have done it by now already... but for some reason I'm not so sure. It is rather complicated and I think counter-intuitive, besides being labelled "impossible" even BEFORE Tesla began work on it. He knew at the time that he was working on something that the prominent scientists of his day considered impossible. Regardless, I've seen enough evidence that it just might be possible that I think it is worth the investment to find out once and for all one way or the other.

So anyway if anyone is interested and would like to help or just follow along as things progress, I've started a crowdfunding campaign to help defray some of my expenses. I'm also posting updates to my Facebook page from time to time.

https://www.gofundme.com/2fsahck

https://www.facebook.com/tom.booth.31508

If it works then I'll definitely be building some model engines to make available and maybe eventually even some real power producing engines to market, but I do not intend to get rich or anything. I suspect it wouldn't be patent-able at this point anyway as Tesla wrote about it over 100 years ago.

Wish me luck.

[Ernst]

First of all I wish you luck on this project.

If you read Tesla's article you will see that the whole 'trick' of his invention is in the conversion of attracted energy from the environment.
As he proposes to cool a certain place, the energy that is attracted will be heat. There is no way around that. This heat then needs to be converted into another form of energy BEFORE it heats up the 'cold spot' that you have created.

This conversion is in fact THE invention, without it any attempt is hopeless.
So what I would like to ask you is this:
which conversion process will you be using?

(if you have a look at the 'ere many generations pass' thread, you can read my take on this. But... it is a lot to read... )


Ernst.

[iflewmyown]

Tom, Have you seen these?

The Eskeli patents which I have been able to locate are:
3,650,636
3,719,434
3,748,054
3,748,057
3,758,223
3,761,195
3,795,461
3,809,017
3,834,179
3,854,841
3,861,147
3,874,190
3,879,152
3,889,471
3,895,491
3,919,845
3,926,010
3,931,713
3,933,007
3,933,008
3,937,034
3,938,336
3,939,661
3,949,557
3,961,485
3,962,888
3,972,194
3,972,203
3,981,702
3,986,361
4,003,673
4,005,587
4,012,164
4,012,912
4,030,856
4,044,824
4,047,392
4,050,253
4,057,965
4,060,989
4,068,975
4,077,230
Rotary Gas Compressor
Rotary Ejector Compressor
Reaction Turbine
Rotary Compressor with Cooling
Reaction Rotor Turbine
Compressing Centrifuge
Compressor with Cooling
Heat and Steam Generator
Turbine with Heating and Cooling
Turbine
Sealed Single-rotor Turbine
Sealed Single-rotor Turbine
Turbine
Dual-rotor Dual-fluid Turbine
Turbine with Dual Rotors
Dual-fluid Single-rotor Turbine
Rotary Heat Exchanger
Turbine with Regeneration
Compressing Centrifuge
Multi-stage Heat Exchanger
Gas Compressor-Expander
Turbine with Heating and Cooling
Power Generator
Turbine
Turbine with Heat Intensifier
Heat Exchanger
Thermodynamic Machine of the Vane Type
Rotary Heat Exchanger
Heat Exchanger
Turbine with Regeneration
Fluid Pressuriser
Rotary Heat Exchanger with Cooling and Regeneration *
Rotor with Recirculation
Turbine
Rotor with Jet Nozzles
Heat Exchanger
Dual Rotor Heat Exchanger *
Thermodynamic Machine
Thermodynamic Machine with Step-type Heat Addition
Thermodynamic Machine with Step-type Heat Exchangers
Fluid Pressuriser
Rotary Heat Exchanger with Cooling
Found in PJK ebook
Garry

[Tom Booth]

First of all I wish you luck on this project.

Thanks!

If you read Tesla's article you will see that the whole 'trick' of his invention is in the conversion of attracted energy from the environment.
As he proposes to cool a certain place, the energy that is attracted will be heat. There is no way around that.

I agree 100% !

Sorry to say I've seen too many completely wild off the wall theories as to what exactly Tesla was driving at. It seems quite plain and simple to me though. Atmospheric heat in the air. His whole thesis has to do with utilizing solar Heat energy stored in the earth, air and water. He seems to finally settle on deriving energy from the heat in the air.

This heat then needs to be converted into another form of energy BEFORE it heats up the 'cold spot' that you have created.

Right.

This conversion is in fact THE invention, without it any attempt is hopeless.
So what I would like to ask you is this:
which conversion process will you be using?

Well, taking a quote from Tesla's article he said:

But was it not possible to realize a similar condition without necessarily going to a height? Conceive, for the sake of illustration, [a cylindrical] enclosure T, as illustrated in diagram b, such that energy could not be transferred across it except through a channel or path O, and that, by some means or other, in this enclosure a medium were maintained which would have little energy, and that on the outer side of the same there would be the ordinary ambient medium with much energy. Under these assumptions the energy would flow through the path O, as indicated by the arrow, and might then be converted on its passage into some other form of energy. The question was, Could such a condition be attained? Could we produce artificially such a "sink" for the energy of the ambient medium to flow in? Suppose that an extremely low temperature could be maintained by some process in a given space; the surrounding medium would then be compelled to give off heat, which could be converted into mechanical or other form of energy, and utilized. By realizing such a plan, we should be enabled to get at any point of the globe a continuous supply of energy, day and night. More than this, reasoning in the abstract, it would seem possible to cause a quick circulation of the medium, and thus draw the energy at a very rapid rate.

To me, it seems that Tesla is here describing the basic workings of any heat engine. Any heat engine requires a temperature differential: "a medium were maintained which would have little energy (i.e. COLD), and that on the outer side of the same there would be the ordinary ambient medium with much energy (i.e. HOT).

The ambient is given as the HOT side. The plan is to create, "by some means or other" a COLD "sink" for the ambient to flow into. This would provide the necessary temperature difference to run a heat engine, perhaps indefinitely as ambient heat is practically inexhaustible so long as the sun keeps shining and warming the atmosphere.

I'm not sure I really agree that the conversion is THE INVENTION. Tesla's idea to me is not so much an invention as the discovery of a principle or process.

To support this he says later in the article:

...other forms of energy into which the heat is transformed in passing from hot to cold. If the process of heat transformation were absolutely perfect, no heat at all would arrive at the low(COLD) level, since all of it would be converted into other forms of energy.... We would thus produce, by expending initially a certain amount of work to create a sink for the heat to flow in, a condition enabling us to get any amount of energy without further effort. This would be an ideal way of obtaining motive power. We do not know of any such absolutely perfect process of heat-conversion, and consequently some heat will generally reach the low level,... necessitating continuous pumping out. But evidently there will be less to pump out than flows in, or, in other words, less energy will be needed to maintain the initial condition than is developed by the fall, and this is to say that some energy will be gained from the medium. What is not converted in flowing down can just be raised up with its own energy, and what is converted is clear gain. Thus the virtue of the principle I have discovered resides wholly in the conversion of the energy on the downward flow.

Tesla accepts here that there does not exist any 100% perfect heat engine. Yet he clearly suggests that this does not matter and that the heat conversion need not be 100% perfect. Some heat will undoubtedly get into the sink necessitating its removal.

In other words, the heat engine used for conversion of the heat into some other form of energy need not necessarily be anything particularly unique or special or unheard of. Tesla is here describing KNOWN technology and working within known parameters.

The main problem as I see it is how to get whatever unconverted heat that makes it into the sink out? How to keep this artificial "cold hole" cold so it does not eventually fill up with heat and the temperature equalize?

Tesla clearly states later in the same article that one component of his "engine" is an air compressor and that this together with other components would constitute a "refrigeration system". He also talks at some length about the Liquefaction of Air and suggests that this is so-to-speak the missing or last ingredient.

It should be noted that the process of air liquefaction and air-cycle refrigeration are virtually one and the same process. Compress air to remove heat and expand it cause a refrigerating effect. If it is made to do work while expanding... all that much better.

Tesla wrote:

I began to devise means for carrying out my idea, and, after long thought, I finally conceived a combination of apparatus which should make possible the obtaining of power from the medium by a process of continuous cooling of atmospheric air. This apparatus, by continually transforming heat into mechanical work, tended to become colder and colder, and if it only were practicable to reach a very low temperature in this manner, then a sink for the heat could be produced, and energy could be derived from the medium.

Air can be compressed and then expanded through some pneumatic device, turbine or engine to effect rapid cooling. In the process of doing work as it expands, air becomes exceedingly cold.

He seems to be describing quite clearly an AIR CYCLE REFRIGERATOR. A modern description of which can be found here:

http://www.grimsby.ac.uk/documents/f...e_research.pdf

"How does air cycle work?
Air cycle refrigeration works on the reverse Brayton or Joule cycle. Air is compressed and then heat removed, this air is then expanded to a lower temperature than before it was compressed. Work must be taken out of the air during the expansion, otherwise the entropy would increase. Work is taken out of the air by an expansion turbine, which removes energy as the blades are driven round by the expanding air. This work can be usefully employed to
run other devices, such as generators or fans. Often, though, it is used to power a directly connected (bootstrap) compressor, which elevates the compressed (hot) side pressure further without added external energy input, essentially recycling the energy removed from the expanding air to compress the high pressure air further. The increase in pressure on the hot side further elevates the temperature and makes the air cycle system produce more
useable heat (at a higher temperature). The cold air after the turbine can be used as a refrigerant either directly in an open system, or indirectly by means of a heat exchanger in a closed system. The efficiency of such systems is limited to a great extent by the efficiencies of compression and expansion,"


So Tesla was working on increasing the efficiency of these two elements.:

"Others had liquefied gases before,... but there was such a vigor about the work of Dewar that even the old appeared new. His experiments showed,... that it was possible to reach a very low temperature by transforming heat into mechanical work,... soon I had in a fair state of perfection the engine which I have named "the mechanical oscillator."... I exhibited several types of this machine, ... On that occasion I exposed the principles of the mechanical oscillator, but the original purpose of this machine is explained here for the first time.

In the process, as I had primarily conceived it, for the utilization of the energy of the ambient medium, there were five essential elements in combination, and each of these had to be newly designed and perfected, as no such machines existed. The mechanical oscillator was the first element of this combination, and having perfected this, I turned to the next, which was an air-compressor of a design in certain respects resembling that of the mechanical oscillator. Similar difficulties in the construction were again encountered, but the work was pushed vigorously, and at the close of 1894 I had completed these two elements of the combination, and thus produced an apparatus for compressing air, virtually to any desired pressure, incomparably simpler, smaller, and more efficient than the ordinary. I was just beginning work on the third element, which together with the first two would give a refrigerating machine of exceptional efficiency and simplicity, when a misfortune befell me in the burning of my laboratory, which crippled my labors and delayed me.

It seems to me that Tesla's "refrigerating machine" was pretty darn near to what is used today to liquefy gases in petroleum distillation plants. Essentially an Air-Cycle cryogenic refrigeration system where Air is the "working fluid" that is compressed and expanded through, in Tesla's plan, his "mechanical oscillator" no doubt. Today the air or gas to be liquefied is made to do work through an "expansion turbine". But any pneumatic device that causes the air to do work as it expands after first being compressed and cooled should serve the basic purpose to one degree or another. That basic purpose is to refrigerate the said "cold hole". to maintain a temperature difference so as to run some kind of heat engine or another. I'd say a Stirling Heat Engine might serve the purpose as well as anything. Just something to put between the Ambient Heat and the refrigerated space to convert the heat into work as it flows from the ambient into the "sink"

All or most of the apparatus Tesla describes serves as a refrigeration system to get rid of any heat that makes its way into the "cold hole". Or as he says, return it to the hot side so that this "waste heat" might in effect "just be raised up with its own energy".

(if you have a look at the 'ere many generations pass' thread, you can read my take on this. But... it is a lot to read... )


Ernst.

Sounds interesting. I'll look for it, though it might be worthwhile to supply a link.

Found it: http://www.energeticforum.com/renewa...ions-pass.html

[Tom Booth]

OK Ernst,

I've read through the thread and supporting material, watched the video and while I found much of it quite interesting I would have to say I've come to a very different conclusion.

I don't believe that Tesla's "Self Acting Engine" had ANYTHING whatsoever to do with electricity. It was PURELY a thermodynamic engine that converted HEAT into WORK or "motive power" that is mechanical motion.

It comprised more than just a simple heat engine in that the motive power derived was in part used to drive a mechanical refrigeration system to maintain a cold "sink" this was nothing more than a gas cycle or air cycle cooling system based upon the heating and cooling effects produced through the mechanical compression and expansion of a gas as in any common refrigerating system.

There was no electrical component and no electrical output whatsoever. It was all entirely thermo-mechanical Not electrical. IMHO that is.

If Tesla's artical is read from that point of view it is all very straighforward. There is no secret or mystery to explain. No code, just basic thermodynamics.

[Ernst]

I understand your more literal interpretation of the article, which seems to be very close to what Peter Lindemann described in his article.
You wrote:

I'm not sure I really agree that the conversion is THE INVENTION. Tesla's idea to me is not so much an invention as the discovery of a principle or process.

To support this he says later in the article:

And the funny thing is that the last line of the text you quoted:

Thus the virtue of the principle I have discovered resides wholly in the conversion of the energy on the downward flow.

is exactly what I meant.
And it is THIS conversion that I was asking you about.
If my interpretation of your answer is correct you intend to build some sort of Stirling engine or turbine (of which Tesla said it would not be good enough) to convert this heat into mechanical energy.

Anyway, I think you would not need an awful lot of money to verify your idea, so you will probably soon be on your way. I am looking forward to seeing your results!


Ernst.

[Peter Lindemann]

Just Chiming In

I understand your more literal interpretation of the article, which seems to be very close to what Peter Lindemann described in his article.
You wrote:

And the funny thing is that the last line of the text you quoted:

is exactly what I meant.
And it is THIS conversion that I was asking you about.
If my interpretation of your answer is correct you intend to build some sort of Stirling engine or turbine (of which Tesla said it would not be good enough) to convert this heat into mechanical energy.

Anyway, I think you would not need an awful lot of money to verify your idea, so you will probably soon be on your way. I am looking forward to seeing your results!


Ernst.

Ernst and Tom,

I completely agree with Tom's assessment of Tesla's Self-acting Engine. It is a purely mechanical machine that converts a temperature differential into mechanical energy, like all other thermodynamic engines. But Tesla goes further. He states that an "artificial cold spot" can be created by the machine so that the heat of the ambient air can be effectively used as the "heat source" for the engine. He goes on to say that Linde's work with the liquefaction of air demonstrated that significant cooling could be obtained in this way.

He believed that it would take an extremely "efficient" engine to be able to accomplish his goal. He first invented his "boundary layer turbine" as his engine of choice, but found it wasn't good enough. He then invented his mechanical oscillator, which he believed was efficient enough. In spite of this, he never demonstrated a working model.

What we know today is that the actual "efficiency" of a machine is far less important than its system COP. In other words, it doesn't matter if all of the parts of a system operate at 50% or even 20% efficiency as long as the machine is fully powered by a source of energy freely available in the environment.

In my lecture Open System Thermodynamics, I suggest that Tesla's vision can be accomplished by a combination of a "regenerative heat pump" that recycles both its mechanical energy and its heat, and then uses the temperature differential to further drive a "heat engine" designed to operate "efficiently" in that temperature range. I also suggest the use of "rotary vane turbines" in the machine, but any mechanism that accomplishes the proper functions at each stage will work.

Tom's ideas are very much in line with what I have just explained. He simply has suggested that my idea of the "regenerative heat pump" can be replaced by a "Sterling Cycle" device with a few check valves to create the initial compression of the working fluid. My only concerns about Tom's designs are whether the "flow rate" of the air through the system will produce a sufficient temperature differential to produce a sufficient production of mechanical energy at his output device. The engineering of this device will boil down to the proper scaling of the various components to each other and to keeping friction down to an absolute minimum. Otherwise, "there is no reason why it shouldn't work" as Tom says.

When using air as the "working fluid" in these sorts of machines, the temperature range becomes problematic below 32F (0C) because of the moisture content tending to freeze. This exact issue is what stopped Thomas Edwards from developing an air based air-conditioning system for automobiles in the 1970s.

All "air based" self-running machines I am aware of use Bob Neal's principles of using a tank of compressed air to run an engine and keep the air pressure up by using "tank pressure" to compress the air instead of the mechanical energy liberated at the engine. This, too, is a thermodynamic engine that takes in ambient air, vents cold air, and produces mechanical energy while recycling the heat and pressure that haven't been converted to engine output yet. But these machines usually operate at pressures of 50-100 psi and temperatures above 100F.

All of the principles to build an engine like this have been discussed earlier in this thread. The only thing missing is the specific design, which of course is a critical omission.

Tom, I am interested to see what you can do with your ideas. If you ever want a little help, just PM me. Thank you for keeping this thread alive!!

Peter

[Tom Booth]

I understand your more literal interpretation of the article, which seems to be very close to what Peter Lindemann described in his article.
You wrote:

And the funny thing is that the last line of the text you quoted:

is exactly what I meant.
And it is THIS conversion that I was asking you about.

I don't know, Tesla wrote"Thus the virtue of the principle I have discovered resides wholly in the conversion of the energy on the downward flow.

He was basically turning the usual method of providing heat to a heat engine on its head. Instead of supplying energy in the form of heat he thought; there is already PLENTY of heat in the atmosphere. What we really need is to create a "cold hole" for all that heat to flow into.

That is, starting at the baseline of the given ambient temperature of the air, instead of going UP above the ambient he thought to create a sink for the ambient to flow DOWN into. In this way there would be no need to supply any additional energy.

I would argue that this was what Tesla meant simply due to the fact that ALL heat engines convert heat into mechanical energy "on the downward flow". This is no new discovery or revelation in itself I don't think. Although not long prior to Tesla's statement it was thought that Heat was a literal thing, a fluid and that it was not converted at all but simply flowed THROUGH a heat engine like water through a turbine and came out the other side unchanged.

This idea of heat as some kind of actual THING that flows through a heat engine rather than a form of energy that is CONVERTED by a heat engine seems to persist even down to this day. I think in Tesla's time this was still being debated, I'm not really sure.

If my interpretation of your answer is correct you intend to build some sort of Stirling engine or turbine (of which Tesla said it would not be good enough) to convert this heat into mechanical energy.

That is essentially correct.

One problem Tesla must have encountered I think is that he was limited to working with steel for the most part. Steel is really an awful material to have to use if you are trying to control and direct heat through a heat engine.

Another possibility is simply that the second law of thermodynamics was a more formidable obstacle than Tesla imagined, and his idea simply did not work or could not work, which is what practically everybody tells me.

Anyway, I think you would not need an awful lot of money to verify your idea, so you will probably soon be on your way. I am looking forward to seeing your results!


Ernst.

Not an extraordinary amount of money. No more than would be needed to say, put together an engine AND a refrigerator. However companies do spend millions on developing and perfecting such things for market. A rather crude and quite small "proof-of-concept" model should at least be doable, but would be little more than a curiosity if not developed further.

I am very curious about an image that appeared in the YouTube video you posted in your thread:



Where did this image originate?

It appears to be an Air Liquefaction machine.

-------------------------------
edit: I find a nearly identical image on this page about the Lind Air Liquefaction process excepting for the insertion of Tesla's oscillator.

Notes on Liquifying Air

[Tom Booth]

Ernst and Tom,

I completely agree with Tom's assessment of Tesla's Self-acting Engine. It is a purely mechanical machine that converts a temperature differential into mechanical energy, like all other thermodynamic engines. But Tesla goes further. He states that an "artificial cold spot" can be created by the machine so that the heat of the ambient air can be effectively used as the "heat source" for the engine. He goes on to say that Linde's work with the liquefaction of air demonstrated that significant cooling could be obtained in this way.

He believed that it would take an extremely "efficient" engine to be able to accomplish his goal. He first invented his "boundary layer turbine" as his engine of choice, but found it wasn't good enough. He then invented his mechanical oscillator, which he believed was efficient enough. In spite of this, he never demonstrated a working model.

What we know today is that the actual "efficiency" of a machine is far less important than its system COP. In other words, it doesn't matter if all of the parts of a system operate at 50% or even 20% efficiency as long as the machine is fully powered by a source of energy freely available in the environment.

In my lecture Open System Thermodynamics, I suggest that Tesla's vision can be accomplished by a combination of a "regenerative heat pump" that recycles both its mechanical energy and its heat, and then uses the temperature differential to further drive a "heat engine" designed to operate "efficiently" in that temperature range. I also suggest the use of "rotary vane turbines" in the machine, but any mechanism that accomplishes the proper functions at each stage will work.

Tom's ideas are very much in line with what I have just explained. He simply has suggested that my idea of the "regenerative heat pump" can be replaced by a "Sterling Cycle" device with a few check valves to create the initial compression of the working fluid. My only concerns about Tom's designs are whether the "flow rate" of the air through the system will produce a sufficient temperature differential to produce a sufficient production of mechanical energy at his output device. The engineering of this device will boil down to the proper scaling of the various components to each other and to keeping friction down to an absolute minimum. Otherwise, "there is no reason why it shouldn't work" as Tom says.

When using air as the "working fluid" in these sorts of machines, the temperature range becomes problematic below 32F (0C) because of the moisture content tending to freeze. This exact issue is what stopped Thomas Edwards from developing an air based air-conditioning system for automobiles in the 1970s.

All "air based" self-running machines I am aware of use Bob Neal's principles of using a tank of compressed air to run an engine and keep the air pressure up by using "tank pressure" to compress the air instead of the mechanical energy liberated at the engine. This, too, is a thermodynamic engine that takes in ambient air, vents cold air, and produces mechanical energy while recycling the heat and pressure that haven't been converted to engine output yet. But these machines usually operate at pressures of 50-100 psi and temperatures above 100F.

All of the principles to build an engine like this have been discussed earlier in this thread. The only thing missing is the specific design, which of course is a critical omission.

Tom, I am interested to see what you can do with your ideas. If you ever want a little help, just PM me. Thank you for keeping this thread alive!!

Peter

My design for an engine has changed a bit since I made that previous drawing. Actually an earlier design was quite a bit different. The various components were all on one shaft, similar to a bootstrap system, It even had the Stirling engine with a rotary displacer on the same shaft, but this was impossible to draw on paper. I later came up with that "exploded view" which was less accurate but at least somewhat comprehensible showing all the components and how they worked together.

Recently I've been thinking that incorporating an "equalizer" at the start of the compression tubing might be a good idea, allowing for easier initial compression.

That is, a double check valve in a pipe inside the pipe leading to the top HOT side of the Stirling.

Theoretically this would allow relatively cool ambient air to be compressed into the "equalizer" which air would then pick up additional heat and expand through the second check valve into the "condenser" coil. If I understand the function of the equalizer correctly.

[Tom Booth]

Here is a YouTube video of a very simple Stirling Engine running on dry ice. There are lots of similar videos using regular ice, liquid nitrogen, snow, ice water... the basic idea being to have the engine run on the ambient heat in the air. This is a heat engine running on a "cold hole" or "sink".

Would it be possible to add to such a small model engine some kind of very small air compressor? Why not use whatever energy such a little engine could generate to operate a small system for compressing and expanding air to create a temperature differential.

IMO that is essentially what Tesla had in mind or what he was actually working on, though he was not working on just a simple "proof-of-concept" model, he was trying to go all out and get down to cryogenic temperatures and produce a machine that would be practical for real power production.

[VIDEO]https://www.youtube.com/watch?v=si1iGuigAiQ[/VIDEO]

It should be noted that Tesla could not have been familiar with this type of Low Temperature Difference Heat Engine. The LTD Stirling Engine was not invented until 1983 by Ivo Kolin at the University of Zagreb Yugoslavia. So my feeling is that it may very well NOT BE NECESSARY to use the extremely cold cryogenic temperatures Tesla probably assumed would be necessary.

In other words, I'm not a purist trying to replicate Tesla's engine exactly. I'm just trying to put something together that would demonstrate the PRINCIPLE while also taking advantage of any advancements in technology that have transpired since Tesla's day.

[Tom Booth]

Also a compressor does not have to be very large or compress a great deal of air to generate quite a bit of heat.

These "Fire Pistons" are very simple, like a very small bicycle pump. Probably something smaller yet would be necessary if it were going to be powered by a little LTD Stirling. But an LTD Stirling can also run on as little as a 2 degree temperature difference. So how much air would such a tiny air compressor need to compress? Would it be enough?

[VIDEO]https://www.youtube.com/watch?v=mnvT3YQxiMs[/VIDEO]

It should also be remembered that the real reason for compressing air is not so much to generate heat but rather to generate COLD. This would be accomplished by maintaining the air under pressure, allowing it to cool, then letting it expand at which point it would get colder than ambient. How cold? Hopefully cold enough.

One more thing to note about this Fire Piston video is that the fire piston is made of metal! Looks like aluminum. This is NOT GOOD in terms of retaining heat. Aluminum transmits heat faster than anything else on earth I think, which means that the air in the fire piston must be compressed very suddenly to prevent the heat from having any time to dissipate. In a heat engine, where the heat would be dissipated directly INTO THE HEAT ENGINE WHERE YOU WANT IT TO GO, such rapid compression shouldn't be necessary.

[Ernst]

@ Tom,

The image you found was indeed the base for the image in my video.
But as it did not clearly showed an oscillator I changed it a bit.

@ Peter, I am aware of your interpretation and I already mentioned it too. I could of course go into details explaining why I believe it is not possible to build this engine with a 'normal' gas or air, while it IS possible with electron gas. But I think you all know the 2nd law of TD and the fact that electrons can be manipulated with electric and magnetic fields, so I won't be telling you anything new.
The way to go is to just build the system that you believe should work, and find out.
I will also keep you informed of my progress, which is always much slower than I hoped it would, but until now has never failed.


Ernst.

[Tom Booth]

@ Tom,

The image you found was indeed the base for the image in my video.
But as it did not clearly showed an oscillator I changed it a bit.


Ernst.

OK, interesting. Though, given your views regarding Tesla's machine, I'm a bit puzzled.

[Ernst]

Puzzled?
How?