Fool wrote: ↑Fri Sep 27, 2024 7:23 am
VincentG wrote: ↑Thu Sep 26, 2024 4:22 pm
No doubt, any energy extracted from this should come from the mass of the bird impacting some stop at the end of its travel. It might help to add as much weight to the top and bottom of the bird as possible so there is more mass in motion.
Adding mass to the bird would be similar to adding mass to a flywheel. Nothing more. It is the change in height of the inside fluid that matters. That is related directly to ∆T.
The bird gets top heavy from the heat entering the bottom,
and less but most heat leaving the head. ...
...
I get the impression "fool" on this forum is not an individual but exhibits a number of rather distinct and varied personalities, attitudes and opinions, often contradicting one another.
The various staff over on the science forum from which I was unjustly banned perhaps? Too curious and intrigued or insulted and annoyed by my experiments and criticisms to simply lurk in silence, but some more open minded and more intelligent and rational than others. Some humble, receptive and even appreciative, some hostile, vengeful and irrational.
Be that as it may...
About the comment above:
"most heat leaving the head"
This is the crux of the issue and the idea on which Tesla's proposed "Self-Acting Engine" depends,... Or rather, Tesla's idea depends on this statement being FALSE.
Conservation of energy, if HEAT is
energy and not a fluid, would dictate that energy cannot be used to run a heat engine producing an output of energy in one form, (the mechanical motion of the bird) force X distance but then also continue on through the heat engine as heat: "leaving the head".
Rather, the heat/energy is converted into mechanical motion. Molecular motion is converted to sensible movement of the engine. The heat, in effect is "used up" and this USING UP of heat results in a drop in temperature.
As previously discussed, I'm not entirely certain this principle is applicable to the bird as heat engine, in the same way it may be applicable to a Stirling type heat engines, or if it is true at all. The "ice bomb" engine concept throws the whole idea of "heat" as a motive force out the window in some ways.
Expansion of ice upon freezing, removing heat, contradicts the whole thesis of heat engine operation by expansion that results from ADDING "heat". In a thermal engine that relies on expansion that results from cooling, where does that leave us, as far as our calculations that are based on an opposite principle: expansion through heating?
How is "heat" CONVERTED to an expensive force or "work" if heat is removed to produce the expansive force?
Theory, somewhat adrift at sea...
The idea that "heat" energy is converted by the bird would tend to suggest that heat is "used up" in operating the bird and therefore does not reach the head at all.
In that case, the initial evaporation would produce the ∆T which then the "heat" entering the lower bulb would never get a chance to nullify. The bird should run continuously without any further need for continued evaporation.
Of course, the birds head will be inevitably re-heated by the surrounding ambient heat in the air, regardless of heat reaching it through the internal working fluid or not.
So, can we apply my "insulating the sink" experiments to the bird?
https://youtube.com/playlist?list=PLpx2 ... fOqG4XSYz0
Get the bird running until the heat is good and cold from evaporation, then cover the head with cellophane and an insulating blanket.
How long will it run on the residual cold?
Will the "using up" of heat internally cause a refrigerating effect in the head, as I have apparently seen and demonstrated by my Stirling heat engines experiments?
Maybe the birds head could be cooled by other means, then kept insulated. An insulated head, protected from warming by the surrounding ambient heat should stay cold longer than an exposed head, so the bird with its head insulated should run longer, as has been seen in a Stirling engine when the cold side is insulated when running on ice.
Because "heat"/energy is converted to a different form by the engine then at a minimum, as stated above: "less but most heat leaving the head".
That is, less heat would leave the head of an actively operating bird/heat engine than would leave the head of an inoperative bird/heat engine.
The problem, though, as previously mentioned, the birds as received from the manufacturer are not identical. The two I ordered could not be synchronized for comparison.
If I ordered a dozen more, perhaps two could be found that were near enough to identical for running some meaningful comparisons.
They are relatively inexpensive, so I may just do that. Certainly more economical than the model Stirling engines.