Search found 110 matches
- Fri May 10, 2024 2:38 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's Ambient Heat Engine revisted
- Replies: 154
- Views: 2009
Re: Tesla's Ambient Heat Engine revisted
If that is truly the case, then the gas laws imply that the temperature of the fluid must also be equal, everywhere. This is another case where it helps to think of energy flow into the engine, rather than heat. Glad when you chime in Mike B. I think this ties in nicely with your thoughts on "...
- Thu May 09, 2024 3:59 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's Ambient Heat Engine revisted
- Replies: 154
- Views: 2009
Re: Tesla's Ambient Heat Engine revisted
It's just one wishy-washy sequence in essentially an open chamber. The gas is free to move around. Even with the displacer fully raised, convection causes the cold gas to sink and be replaced by hot gas, which in turn is cooled, and again sinks. I know I mentioned the speed of sound before, but as ...
- Tue May 07, 2024 7:14 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's Ambient Heat Engine revisted
- Replies: 154
- Views: 2009
Re: Tesla's Ambient Heat Engine revisted
"Pretty obviously the elevated heat signature appearing around the power piston could only be from "work"."
Why is that?
Could the heat not come from the working fluid?
Why is that?
Could the heat not come from the working fluid?
- Fri May 03, 2024 9:21 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Heating a LTD Stirling engine efficiently
- Replies: 5
- Views: 137
Re: Heating a LTD Stirling engine efficiently
If you do want to have the two faces have matching grooves, then think about using casting for one or both.
- Fri May 03, 2024 6:33 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's Ambient Heat Engine revisted
- Replies: 154
- Views: 2009
Re: Tesla's Ambient Heat Engine revisted
Tom, IIRC you were the first to mention fridge's. We seem to be in agreement that they have little relevance to this discussion. Average <anything> is ALWAYS a thing, and while it may not be entirely easy to predict, the average temperature of the working fluid of a hot-air engine is definitely a th...
- Thu May 02, 2024 9:15 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's Ambient Heat Engine revisted
- Replies: 154
- Views: 2009
Re: Tesla's Ambient Heat Engine revisted
For heat to be removed from the cold end, by the working fluid, it must have an _average_ temperature throughout the cycle, that is below that of the cold end. It's easy to postulate that the working fluid temp might drop below that temp briefly, but I'm really struggling to see how it could be bel...
- Tue Apr 30, 2024 4:31 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Stirling engine speed/accelleration control
- Replies: 4
- Views: 174
Re: Stirling engine speed/accelleration control
Not something I've actually tried yet, but my idea is to de-couple the displacer from the power piston, and instead drive it with an electric motor. In theory, the speed of the engine would directly follow the speed of the displacer, and of course if the electric motor is stopped completely, the eng...
- Tue Apr 30, 2024 4:28 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's Ambient Heat Engine revisted
- Replies: 154
- Views: 2009
Re: Tesla's Ambient Heat Engine revisted
For heat to be removed from the cold end, by the working fluid, it must have an _average_ temperature throughout the cycle, that is below that of the cold end. It's easy to postulate that the working fluid temp might drop below that temp briefly, but I'm really struggling to see how it could be belo...
- Thu Apr 25, 2024 8:41 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Stirling-Apha heat pump, and finned pistons
- Replies: 6
- Views: 530
Re: Stirling-Apha heat pump, and finned pistons
I think you've already noticed, but the big issue with any alteration / increase of surface area is that it tends to also increase the dead volume, which is generally considered "a bad thing" but maybe its a worthwhile trade-off?
- Thu Apr 04, 2024 7:04 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 510
- Views: 26832
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Tom,
If you could build an engine that had ice at the cold end, but that ice never, ever melted, what role would it have within the engine?
My intuition says that if no heat/energy transfers into the ice, then it isn't having any effect on the engine cycle.
If you could build an engine that had ice at the cold end, but that ice never, ever melted, what role would it have within the engine?
My intuition says that if no heat/energy transfers into the ice, then it isn't having any effect on the engine cycle.
- Thu Mar 14, 2024 6:32 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Model LTD max power effort
- Replies: 106
- Views: 48466
Re: Model LTD max power effort
I guess it's all theoretical to a degree, but if going with kinetic theory then each gas atom or molecule is moving independently with a lot of space in between hardly interacting with each other at all. If that is true than the idea that some of the hot gas can exert "pressure" to the co...
- Fri Mar 01, 2024 4:49 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Accordion style heat input plates
- Replies: 53
- Views: 17824
- Fri Mar 01, 2024 4:33 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: New Heat Engine
- Replies: 3
- Views: 3374
Re: New Heat Engine
The efficiency of this kind of engine is going to depend not just on the relative heat of hot versus cold reservoirs, but also on how much energy is required to pump your working fluid around. This is fundamentally the same as for a Hot-Air engine, except that water has much more mass than air does....
- Thu Feb 29, 2024 10:17 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Choosing bearings for Flywheel
- Replies: 7
- Views: 3706
Re: Choosing bearings for Flywheel
Not directly answering your question, but my advice would be to make the flywheel narrower and larger in diameter.
- Fri Feb 09, 2024 1:57 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Regenerator Material Selection
- Replies: 8
- Views: 4026
Re: Regenerator Material Selection
My own personal, but completely unproven theory is that a regenerator will improve the efficiency of some badly designed engines, but I just can't see how it could improve on a theoretically perfect engine, as it will rob pressure when it absorbs heat.