Tesla's Ambient Heat Engine Theory - Right or Wrong ?

[Tom Booth]

Thanks for your comments Gianna, I get board when I don't have someone who consistently misconstrues everything I post. It's no fun when everybody agrees with me. Where are all the skeptics and hecklers? I was hoping to hear from TinselKoala. And of course thanks to everyone else who has contributed useful information, input, links etc. Please don't feel ignored. I do appreciate any and all input.

I can't see this working on an ongoing basis.  Assuming the ambient heat is at a higher temperature than than the cold box initially then it will run. Now, if you COULD convert all the heat to work then it would continue indefinitely as the cold sink would always be cooler than ambient.

However we know from Carnot that this is not possible. Some of the heat from the ambient source will be delivered to the cold sink and the temperature will start to rise. Eventually the cold sink temperature will reach ambient temperature and the engine will stop, unless there is some way to cool the cold sink again.

What you say here is, of course, a given. That is, it is the conventional wisdom, the unquestioned truth. Nobody in their right mind would think otherwise or waste precious time and money on a hopeless endeavor that is doomed to failure from the start.

Who was it that said something or other...?

Oh yeah,:

The law that entropy always increases, holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations — then so much the worse for Maxwell's equations. If it is found to be contradicted by observation — well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.    "

         --Sir Arthur Stanley Eddington, The Nature of the Physical World (1927)

But does entropy increase, decrease or stay the same if this idea were to work ?

I think an argument could be made that entropy would increase.

The earths atmosphere and the heat in it is rather orderly and stable. It you could take that heat and let it find a way to escape and disperse through the electrical grid to destinations unknown or perhaps to be emitted by some light source or as some other electromagnetic impulses to finally radiate out into space to the far reaches of the universe, which condition is more orderly ?

If such an engine were found to work, I have little doubt that the proponents of the second law would figure out some way to explain it. What is a condition of order or disorder but a subjective opinion ?

I believe Tesla's theory anyway. At least I won't dismiss his idea until I, or someone else at least makes some feeble attempt at applying it. Or conducts some experiment to test it. It doesn't appear to me to be all that formidable a task.

Trying to cool the exhaust  is not possible using a one way trap as you propose. If the exhaust temperature is lower than ambient (as it must be for the engine to run) then the exhaust heat wont flow naturally back to the ambient source. To do so would require us to do work. Exactly the same amount of work or more than could be extracted by the engine in the first place. Net energy result of the cycle is zero or negative.

Thankfully, you have entirely misconstrued and misunderstood the purpose and function of the "one way trap", and apparently also the entire manner of operation of the whole engine and that of Stirling Engines at large or in general.

First of all, there is no "exhaust". This engine is basically a Stirling Engine. Stirling Engines do not have an exhaust. The air does not leave the cylinder.

Because there is no exhaust, of course, the purpose of the trap cannot possibly be to "cool the exhaust".

Again, the exhaust temperature is not lower than ambient because there is no exhaust.

The exhaust heat will not flow back to ambient. If there is no exhaust then of course, there can be no exhaust heat. Right ?

Therefore; Returning the exhaust heat will not require any work because there is no exhaust and therefore no exhaust heat.

The heat passes into the box via the engine and only the engine. It goes in but does not come out. Remember ? It disappears! It is converted into work. Some of that work is used to effect cooling, the rest goes out as electricity so as to increase the entropy of the universe. The kinetic energy of the hot air molecules impacts a small portion of the engine. Heat is taken in by the outer hull of the engine and transferred to the air inside the engines cylinder. That air expands and drives the engine. Part of the power supplied is utilized for generating electricity, the rest is used for cooling. By the time this is accomplished the heat has been used up. If there was an exhaust there would be no heat (above ambient) to be exhausted, but in fact there is no exhaust.

The purpose of the trap is the same as the diaphragm in the earlier illustration. It simply provides an easily movable barrier that prevents hot ambient air from mixing with the cold air surrounding the engine while allowing the pressure of the atmosphere through. Air does not pass through the trap in either direction, except possibly a very small quantity may bubble through in the case of extreme changes in atmospheric pressure.

Your one way trap idea epitomizes what is required to make this or Tesla's idea work.

Indeed.

It needs to be able to transfer heat energy from a low temperature to a higher one while consuming less work than is able to be generated by a heat engine operating in the opposite direction.

Classical thermodynamics says this is impossible. Quantum physics is less sure, but statistically the classical result holds true.

This engine is much like an oscillating electrical circuit maintained by intermittent pulses of electricity.

The problem with electricity however is that we do not have a ready and inexhaustible supply on hand to maintain such oscillations indefinitely. Heat, on the other hand is in the air, continually supplied by the sun and renewed on a daily basis. The engine takes in intermittent pulses of HEAT to maintain the oscillations at one end and pulses of atmospheric pressure acting in the reverse at the other end.

Possibly it won't work. Nevertheless, it doesn't seem like a very difficult experiment to carry out. Ay least if we can get past the notion that a trap to keep out hot air is actually an exhaust pipe to let out hot air.

[Tom Booth]

Perhaps this will make things more clear.

(It may take a while for the animation to load.)

Never mind, for unknown reasons I'm not able to post an animated Gif here. sorry.

By way of explanation, the dark blue stuff in the trap is a fluid. Probably antifreeze given the temperature. When the engine runs it just moves in the tube back and forth from the pressure changes but no air enters or escapes.

BTW the light blue in the box surrounding the engine is just cold air. Blue to indicate the cold temperature, while outside the box is regular ambient air.

Hope that helps.

edit: I uploaded the gif here: http://calypso53.com/stirling/amb_eng_anim.gif

[Tom Booth]

Ok, there is no exhaust as such as in an exchange of gasses, but heat MUST be transferred to the cold sink. I'm calling that 'exhaust' in this instance. If there was no heat transfer to the cold sink the the engine would not run.

I don't suppose you actually took the time to read Tesla's paper. But the theory of his is; And this part is not even controversial, A quantity of heat enters the engine. Some portion of that heat is "converted" into "Work". Perhaps some portion of that heat which is not converted into work reaches the sink.

Tesla surmised or believed or theorized that the energy derived from the heat could be used to remove whatever energy reached the sink.

In his own words:

As regards heat, we are at a high level, which may be represented by the surface of a mountain lake considerably above the sea, the level of which may mark the absolute zero of temperature existing in the interstellar space.  Heat, like water, flows from high to low level, and, consequently, just as we can let the water of the lake run down to the sea, so we are able to let heat from the earth's surface travel up into the cold region above.  Heat, like water, can perform work in flowing down, and if we had any doubt as to whether we could derive energy from the medium by means of a thermopile, as before described, it would be dispelled by this analogue.  But can we produce cold in a given portion of the space and cause the heat to flow in continually?  To create such a "sink," or "cold hole," as we might say, in the medium, would be equivalent to producing in the lake a space either empty or filled with something much lighter than water.  This we could do by placing in the lake a tank, and pumping all the water out of the latter.  We know, then, that the water, if allowed to flow back into the tank, would, theoretically, be able to perform exactly the same amount of work which was used in pumping it out, but not a bit more.  Consequently nothing could be gained in this double operation of first raising the water and then letting it fall down.  This would mean that it is impossible to create such a sink in the medium.  But let us reflect a moment.  Heat, though following certain general laws of mechanics, like a fluid, is not such; it is energy which may be converted into other forms of energy as it passes from a high to a low level.  To make our mechanical analogy complete and true, we must, therefore, assume that the water, in its passage into the tank, is converted into something else, which may be taken out of it without using any, or by using very little, power.  For example, if heat be represented in this analogue by the water of the lake, the oxygen and hydrogen composing the water may illustrate 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 level, since all of it would be converted into other forms of energy.  Corresponding to this ideal case, all the water flowing into the tank would be decomposed into oxygen and hydrogen before reaching the bottom, and the result would be that water would continually flow in, and yet the tank would remain entirely empty, the gases formed escaping.  We would thus produce, by expending initially a certain amount of work to create a sink for the heat or, respectively, the water 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, which means to say, in our mechanical analogue, that some water will arrive at the bottom of the tank, and a gradual and slow filling of the latter will take place, 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.

Now perhaps Tesla was over optimistic. It is not necessarily so easy to get a little heat out of a cold heat sink. Generally the colder it gets the more difficult it becomes to remove what little heat remains. So I see no guarantee that Tesla was absolutely right. Nevertheless, I see no guarantee that Carnot or the other fathers of the second law of thermodynamics were entirely infallible either. One or the other may have been overlooking something. But from my own research and studies, I think there is a great deal of evidence in support of Tesla and I have found no evidence that anyone has ever actually tried to apply or test his theory in an objective scientific manner. Carnot was a man who formulated an opinion. An opinion based on the idea that Heat is a fluid. That it runs through a heat engine like water over a water wheel and so must come out the other side. Tesla had the insight to realize that just wasn't the case. Heat is a form of energy. It doesn't necessarily have to come out the other side but can be converted into another form of energy. Something other than sensible heat.

The end result is the cold sink heats up until it reaches ambient at which point the cycle stops.

Then you have to move that heat through your one way trap back to ambient. There is no way to achieve that without either supplying work or ambient temperature is less than the cold sink.

Your opinion might carry more weight if you could explain in detail exactly how a "resonant effect" causes a piston to reverse its course in a cylinder and hurtle inward against its own momentum as well as against the expanding hot air headed towards the sink. I doubt if you can, yet Tesla's theory throws light on the subject and explains it quite satisfactorily IMO.

Can you explain the behavior of the engine in this video?

http://www.youtube.com/watch?v=cAyw_dOioMU

There is an additional video I came across:

http://www.youtube.com/watch?v=PflY-AFp15c

It shows infrared imagery of a similar type of Glass Test tube Stirling.

One thing that I think is noteworthy is how long it seems to take before enough heat penetrates the glass tube before this engine can get started. The lack of any apparent "resonant" effect is also conspicuous.

My point being that if it takes the heat that long to get into the engine through the glass, it seems reasonable to assume it would take just as long to get back out through the glass to the sink, in the previous engine which is all glass.

I would appreciate it, if you really believe it, if you would tell me more about this so-called "resonant effect" and how it is able to stop a piston in its tracks and cause it to reverse its course in an instant of time, or tell me by what mechanism exactly it is you believe this is taking place.

I personally can see no other rational explanation than that the heat is converted, as Tesla surmised, into another form of energy.

With the linear generator, this conversion takes place on both the forward and backward stroke of the piston. That a conversion of energy is taking away the heat in the expanding gas, converting that heat into work, seems to me the only satisfying explanation.

If you really believe in your "resonant effect" theory than I do wish you would explain in detail just exactly how that works.

You wrote above: "The end result is the cold sink heats up until it reaches ambient at which point the cycle stops."

You seem to realize that once a balance is achieved things come to a halt. When temperatures equalize, then there is noting to drive the engine.

So again, please explain to me how the piston reverses its course once the gas that drives it has given up its heat to the heat sink and temperatures have equalized? Without the momentum of a flywheel to push it back, what causes it to stop and reverse its course and return from whence it came, not only against its own stored up momentum and against the expanding hot gas that pushed it out in the first place but also against the electromagnetic force of the linear generator.

Resonant effect ?

[Tom Booth]

It's no more complex than his observation at the beginning of the video that the device tended to oscillate at its natural frequency for a while even without heat applied.

I assume you mean this video:
http://www.youtube.com/watch?v=DyPxNNJQo9M

In the beginning he simply states: "What I noticed by accident was that if I took the con rod from the flywheel and applied a small impulse to the piston that it would oscillate for a few seconds backward and forward within the bore."

He does not specify whether he had been running or applying heat to the engine or not, but later in the video he demonstrates how the engine will run for a few seconds after the heat source is removed. In the comments someone stated : "the extra movements of piston after the heat source is taken away is just the heat that is left behind in the tube being used up." - which he did not dispute.

At no time does he suggest that any oscillation takes place without heat having been recently applied to the engine and at no time does he demonstrate anything of the sort.

I suppose if you really think a heat engine of any kind can run at all without heat then we could ask him that specific question if he is still around.

The mass of the piston is alternately compressing and expanding the gases. Running the motor at that frequency would not require a flywheel.

Oh, now it is the "mass of the piston" that is running the engine compressing and expanding the gas and not the other way around.

Your explanation is sorely lacking in details.

If you can possibly do so, please take us through the cycle of just how a resonant effect engine operates from start to finish.

IMO, you may as well say that this resonant effect can stop a bullet and drive it back down the barrel of a gun.

Mass in motion tends to stay in motion unless it comes up against or is diverted by some outside force. It does not just stop, reverse course and start compressing gas in the opposite direction of its travel.

BTW here is another video from the same gentleman. He first runs the engine with a flywheel, then removes the flywheel and runs it with a linear generator and shows it generating electricity. He then short circuits the generator coils and the engine stops and refuses to run at all. then he runs it with no load.

http://www.youtube.com/watch?v=J9ILlx3XPZ4

I would say that a flywheel may prevent such an engine from running at its "natural frequency" but it still runs just the same. Without the flywheel to slow it down it will run at a constant speed but it is not the frequency or "resonance" that makes it go. That would take some stretch of the imagination IMO.

I think it would be very interesting to run such an engine with a variable load. Then I think it would be obvious that the engine is capable of running at different speeds and not just at some fixed frequency dictated by its dimensions or mass.

[Tom Booth]

Another thing I find quite interesting about this type of Stirling Engine and the one in this last video in particular running with the flywheel...

In the earlier videos the guy mentioned about how he installed a rubber bumper in the first and a spring in the second engine to keep the piston from banging into the bottom of the cylinder chamber as it travels back TOWARDS the source of heat.

This seemed to indicate to me that the contraction phase was stronger than the expansion phase, due to some degree MORE heat being "disappeared" than what was supplied.

I explained how this is possible based on Tesla's theory.

The piston is driven out by the expanding gas until a point of equilibrium is reached. The kinetic energy of the expanding gas has largely been converted or transferred to the piston or elsewhere. Once reaching a point of balance, Temperature and pressure equalized, the piston should stop. In most engines at this point the momentum of the flywheel would be needed to push the piston back.

The piston continues beyond the point of equilibrium due to its momentum. At this point it is expanding the gas causing a drop in pressure and temperature. But on the return stroke, the engine is still doing "work" if only to overcome friction, therefore more heat is being converted or transferred from the gas on the return stroke.

The net effect of all this is that the engine converts more heat in the gas into other forms of energy or the heat appears elsewhere as friction etc. but the gas itself is dropping in temperature below that of the sink. In effect, it has, towards the end of its outward stroke, become a refrigerator.

So the piston actually returns towards the heat source with more force than it had on its way out.

What I find interesting in this last video, in light of the above, is the way the engine is hopping across the table TOWARDS the heat source.

Remember the piston bumping into the orifice ?

With the flywheel attached the piston cannot travel as far inward as it would like, but the MOMENTUM is still there, resulting in the engine being bumped toward the heat source with every revolution.

I don't think this can be explained simply due to the flywheel being out of balance. If that were the case the motion would be more or less random in any which way not consistently in one direction, toward the heat source, the same as when the piston was bumping into the end of the chamber, again TOWARD the heat source.