Stirlingengineforum.com

Fool pretending he knows all about things he's pretty obviously never heard of before or he would not be advocating kinetic theory (gases always repel "forever" with no attractive forces or other interaction) as the ultimate reality or other 1820's heat engine theory, long ago rendered obsolete.

Fool wrote: ↑Wed Nov 06, 2024 11:32 pm .

A ping pong ball hits your paddle without being attracted to it. It pushes back in the form of a bounce. Imagine 6.022x10^23 more ping pong balls, per mile.

Yes, none of the simulations use molecular spin.

Electrons don't spin around an atom. Quantum mechanics doesn't work that way. It's called an electron cloud. And energy levels.

Quantum mechanics and relativity/lightspeed don't mix well. Nor gravity and quantum theory.

Ohhh, ahhh, we are so impressed.

What a dolt.

VincentG wrote: ↑Thu Nov 07, 2024 8:28 am I’m not sure where you all were concerned with gravity, but it certainly plays a role in these engines, or at least can be used to one’s advantage.

Maybe you can expand on what you mean.

In terms of the Lennard-Jones potential, gravity helps pull the particles down and therefore also together so our atmospheric air particles are already being "compressed" or squeezed together before we even begin compressing them in an engine.

.

The 14.7 psi is caused by gravity. The air at sea level is squeezed/compressed by all the air molecules above them. That is why it is the 14.7 psi is not seeking zero pressure by expanding into the lower pressure we call outer space.

The Earth provides the gravity, not the air.

VincentG, The effects of gravity on these engines supply some necessary design concerns for the engineer. Otherwise we would not have all position engines, like chainsaws and airplane engines.

.

Fool wrote: ↑Thu Nov 07, 2024 4:05 pm .

The 14.7 psi is caused by gravity. The air at sea level is squeezed/compressed by all the air molecules above them. That is why it is the 14.7 psi is not seeking zero pressure by expanding into the lower pressure we call outer space.

You're stupid.

How about the gas in the upper atmosphere ? You know, the gas molecules all the way up on top of all the lower down molecules. Why don't they all escape into space? Then the next layer down, and the next, until all the air is gone?

You're a complete idiot trying to refute and deny the obvious, well known and accepted facts.

That is why it is the 14.7 psi is not seeking zero pressure by expanding into the lower pressure we call outer space.

No, that is why the gas is compressed at sea level, by the weight of all the gas on top that is not why the atmosphere doesn't expand into space.

Gas particles attract. Why do you keep trying to deny such an obvious and well established fact. You ignorant dolt.

The Earth provides the gravity, not the air

And the earth formed from gas molecules in space attracting to form a planet numbskull.

The earth would not exist to begin with, but for the .mutual attraction of gas .molecules.

Some would even argue that the molecular attraction of gases (Van der Walls) and gravity are one and the same:

https://arxiv.org/abs/1303.3579

.

Tom Booth wrote:How about the gas in the upper atmosphere ?

They are attracted by the Earth too. Otherwise they would expand off into space, similar to moons, comets, and asteroids. Since no gas is above the top most layer, they are at the lowest pressure level. Darn near zero, but not quite.

Tom Booth wrote:Gas particles attract.

You are not reading me. Gas molecules attract and repel, but the speed of the gas molecules, overrides the attractive force, bounces off the repulsive force, and produces the macroscopic property of pressure, always pushing, never pulling. No such thing as gas contraction, only outside force compression fighting the never zero gas pressure.

Tom Booth wrote:that is why the gas is compressed at sea level, by the weight of all the gas on top

Yes. Compressed by something outside or above it. That is why it goes to zero at greater altitudes. Gravity is the outside force. If there were no gravity, there would need to be a ceiling above it, being pulled down by spring force, or it would expand off into space. As it has done for much lower mass bodies in space. Poof! Gone! If there were no gravity, there would be no planets. No liquid. No solid. Only gas leftover from the big bang.

Tom Booth wrote:And the earth formed from gas molecules in space attracting to form a planet numbskull. [/Quite]

Large masses of gas, LARGE, will coalesces into a gas giant planet, or star, but they are many times more massive than Earth. Earth sized planets need more massive gas particles than nitrogen, to form. Then it is the 'dirt' that attracts the air to the planet, not the gas attracting the gas to the planet. Gasses don't attract if above the boiling temperature. Coalescence requires cooling before the attraction kicks in, during.

Kinetic energy from momentum, bounces off from repulsive potential energy, streaking passed attractive potential energy, when above the boiling temperature/speed/energy.

Again planet coalescence isn't from intermolecular attractions, until cooling and gravity have done their jobs. Those weak and short distance attractions, only apply when the gas drops below the boiling point, or freezing point.

Gasses have too much energy to 'stick'. They bounce.

.

.

The following video explains why all the little details Tom keeps bring up are negligible. It gets as far as explaining why simulating gas with the kinetic theory is acceptable. He also promises to continue with more videos. So far this is the only one I've watched. It is so good I thought I should provide it now.

https://m.youtube.com/watch?v=MXs_vkc8hpY

Enjoy.

.

.

Part 2:

https://m.youtube.com/watch?v=4b80sR-joNY

.

Fool wrote: ↑Fri Nov 08, 2024 2:27 am .

The following video explains why all the little details Tom keeps bring up are negligible.

Liar

It gets as far as explaining why simulating gas with the kinetic theory is acceptable.

"Acceptable" for some rough estimates does not mean more accurate or more realistic.

Please stop derailing this thread with your personal obsession that "gases always push" or "bounce" and "never attract" or only "expand forever".

Get lost moron, you've been proven wrong 10 times over already.

Get a life.

If you want to peddle your obsolete 1820's ideal gas theories, please start your own thread on the subject and stop vampirizing other people's discussions with your idiocy.

The intermolecular forces of attraction and repulsion can be modeled using magnets.

https://youtu.be/ZSNU9GN-NJI

There are many similar videos of such "inverter magnets" or "tractor beam magnets".

I think this makes it clear what is meant by the Lennard-Jones potential when the forces of attraction and repulsion are balanced.

There is a tendency for the molecules to naturally settle in a neutral position, or maintain a distance where the forces of attraction and repulsion cancel out.

If we assume that each gas molecules is essentially motionless, at least from our macro perspective and is in a state of balance in relation to all other gas molecules, (within the confines of a Stirling engine) poised between attracting and repelling, then how might this change the choices we make as far as how we design our engine?

What then is the "pressure" or force that drives our piston?

Rather than the piston being driven by a multitude of direct impacts by individual molecules, the "pressure" of a gas pushing against the piston is more a result of all the gas molecules within the cylinder and the engines hot and cold chambers simultaneously repelling or pushing against each other, like little magnets that have been pushed too close together.

So, using this model, of nearly stationary gas.molecules repelling each other, and thus putting pressure on the piston indirectly, (rather than freely moving gas particles in continual random motion) if true, how might we take better advantage of this fact?

Well, thinking of a Newton's Cradle. The force across the stationary marbles or metal balls in a Newton's Cradle is transmitted from end to end nearly instantaneously. Likewise then, adding heat to and expanding gas at one end of a cylinder would also nearly instantaneously transmit "pressure" to the piston at the other end.

Also, it would matter not at all if the molecules at one end were heated and the rest of the gas molecules at the other end remained cold, the "pressure" would be transmitted regardless, as the "hot' particles do not actually need to make their way through the mass of cold particles avoiding collisions all along the way they merely need to "expand" in place or if not exactly in place, they need only be moved slightly to bring them in and out of direct contact with the hot plate heat exchanger., as they will never travel between the hot plate and the piston at all, but only transmit their "expansive force" or increased force of repulsion to the piston indirectly through the mass of adjacent particles.

Infact, logically, it might be an advantage for those other molecules to remain cold as they would be more densely packed, have less random motion and therefore transmit force more effectively. That is, they would be less "spongy" or less elastic and the force transmitted less random.

You would not have an effective Newtons Cradle if instead of hard steel balls you had sponges. The transmission of force would be slower or completely absent.

So, at the very least, this "alternative" model of gas behavior, if true, would tend to modify how we think about designing an engine and what factors are important and what factors might be neglected.

Just for example, having a regenerator, very cold on one side, through which hot molecules must individually travel to individually impact the piston without loosing any more energy than absolutely necessary concerned me greatly, not long ago. But if the hot gas molecules only transmit force indirectly by putting pressure on adjacent molecules, then there should be no concern about this at all. The hot gas molecules do not ever need to actually pass through the regenerator or even come into contact with the cold side of the regenerator at all, they only transmit pressure through the regenerator indirectly through other gas molecules.

After many years spent puzzling over the operation of Stirling engines I came to reject the kinetic theory on the grounds that it simply does not adequately explain how Stirling engine observably operate, but I had no immediate replacement.

I came up with my own theories, sticking with the things I could see first hand through direct experiment were observably true.

Turns out, there are already models of gas behavior that fit the bill and DO adequately explain experimental observations.

"REAL" gas behavior, rather than "IDEAL" Lennard-Jones modeling that includes attractive forces rather than the kinetic model. etc.

What is most notable about this is that force might be transmitted through the working fluid without the transmission of any "heat" at all. The "hot' gas can be expanded on the hot side and just transmit "pressure" to the piston, indirectly while the cold side of the engine, for the most part, remains almost entirely cold. There is no need whatsoever for any heat to "travel" through the engine from the hot side to the cold side.

This provides a satisfactory model of gas behavior that explains my experimental results, that indicate the same.

A Stirling engine can operate just fine while transmitting no heat whatsoever through to the supposed "sink".

A ramification of this line of thinking is that the kinetic theory about the cause of "pressure" must be wrong.

Suppose we have two canisters at the same pressure with a tube in between containing a regenerator.

Now suppose there is a piston in the wall of one of the canisters so we can vary the volume.

Now we heat one canister so the temperature of the gas in that canister increases. At the same time we move the piston so that no air escapes from the hot canister into the still cold canister.

At this point the pressure in both canisters is equal. The two canisters are joined by the pipe, but no heat can cross through the regenerator.

So, how can "pressure" then be the consequence of the impact of individual gas molecules on the walls of the canister, which impacts increase or decrease according to temperature?

The pressure of both canisters is the same, but the temperature is very different. The volume of both canisters is equivalent to the total volume since they are connected by a tube and are really the same volume.

This also explains why an air compressor, putting air into an air tank equalizes with the environment in temperature, but not in pressure.

If a gas were really composed of completely independent molecules that do not interact and if pressure were a function of kinetic energy (temperature) then when the temperature equalized with the ambient temperature then logically it would seem that the pressure would also

The pressure in the tank, then, comes from the mutual repulsive forces of the gas molecules repelling one another because they have been crowded together "too close for comfort" due to their molecular structure and tendency for mutual repulsion at close distances, not their kinetic energy or temperature, zipping around and colliding with the walls of the air tank.

But what is heat in your theory then?
As I understand it, you propose that the fluid molecules are little magnetic balls basically. Then what does heat do to increase that magnetic field?
And how is it taken out by converting it to work in a stirling engine where the hotter molecules don't "travel" much?

Jack wrote: ↑Sat Nov 09, 2024 10:22 pm But what is heat in your theory then?
As I understand it, you propose that the fluid molecules are little magnetic balls basically. Then what does heat do to increase that magnetic field?
And how is it taken out by converting it to work in a stirling engine where the hotter molecules don't "travel" much?

Heat is still heat.the transmission of energy from the hot plate to the piston is just indirect, like a Newton's Cradle

https://youtu.be/0MEVu_Elvwc