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?
Apparently, according to the Lennard-Jones potential model. All molecules attract,
The electrons attracted to the nucleus of the other particles.
But the electrons themselves repel, so when the molecules get close enough they repel.
Heat will cause electrons to jump to higher orbits which it seems, effectively increases the diameter of the .molecule and increases the repulsive forces causing the molecules to move further apart.
Cooling down, then, naturally would have the opposite effect. The electrons drop down closer to the nucleus and the molecules, to that degree attract more and move closer together.
The molecules, I imagine, loose energy without moving much in the same way the first steel balls in a Newton's Cradle transmits energy through the entire line through to the other end.
In a Stirling engine though, the "other end" is the piston, the only thing able to move, everything else, the other gas molecules and walls are "locked in" their positions.
The hot plate causes the gas molecules in direct contact with it to expand. The pressure is then transmitted through the entire volume of gas to the piston almost just as if the expanding molecules were in direct contact with the piston and transferring energy to it.
That would be why, or one reason why heat does not pass through a Stirling engine.
The heat hardly leaves the hot plate at all (relatively speaking. Though there is no doubt billions or trillions of gas molecules in direct contact with the hot plate) so only pressure is transmitted to the piston, which is basically just molecular repulsion between the gas molecules close to, or in direct contact with the piston and the molecules that compose the mass of the piston.
Though the general squeezing together of all the gas molecules (increase in pressure) causes a temporary elevation in temperature throughout all of the gas molecules. This "heat of compression" dissipates or disappears as the piston moves releasing the pressure, then cooling results as the piston momentum begins to allow the gas to expand as the piston continues outward.
So all the gas on the cold plate side, and the cold plate itself can actually grow colder than what it was at the start.
This may be a simplification, or not exactly 100% correct, as most theories or models are only an attempt at explaining or conceptualizing observations.
Factually, many of my experiments and observations of Stirling engines show the cold plate either remaining cold, or actually becoming colder rather than warmer or hotter.
It is generally agreed that the Lennard Jones potential model is a much more accurate model of gas behavior than the "ideal" gas kinetic theory of gas molecules being very far apart and non-interacting.