Search found 110 matches
- Wed Aug 23, 2023 7:47 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Free Piston Stirling Cooler able to cool down a room/house?
- Replies: 5
- Views: 3847
Re: Free Piston Stirling Cooler able to cool down a room/house?
The specs available on that site, at least at first glance, are essentially non-existent. I wouldn't touch it with a barge pole, and in any case, what is being advertised is little more than a basic kit - you would have to do a lot of work to adapt it to actually cool anything.
- Wed Aug 23, 2023 3:25 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Aligning heat "vectors"
- Replies: 25
- Views: 17361
Re: Aligning heat "vectors"
I hadn't heard of a "Jake Brake" before - are they really a thing?
My driving instructor taught me how to use engine-braking, then told me never to use the technique unless necessary, as brakes are somewhat cheaper (and easier) to replace than cylinder linings!
My driving instructor taught me how to use engine-braking, then told me never to use the technique unless necessary, as brakes are somewhat cheaper (and easier) to replace than cylinder linings!
- Tue Aug 22, 2023 5:33 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Aligning heat "vectors"
- Replies: 25
- Views: 17361
Re: Aligning heat "vectors"
I totally agree that the piston would have to remain "in rhythm" with the displacer, but the 'phase angle' would shift. If it shifted far enough, the engine is going to start to "skip a beat" and/or stop completely. I think you might struggle to find a servo that will run fast en...
- Fri Aug 18, 2023 5:49 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: if stirling engine is driven as reversed, does it work as cooler?
- Replies: 94
- Views: 48851
Re: if stirling engine is driven as reversed, does it work as cooler?
Tom, I really don't think it is nit-picking to say that gasses NEVER contract on their own, or that the outward pressure of any gas (by definition) is greater than any inter-molecular forces, or gravitational forces, or dark energy. Besides, surely the whole point of this discussion is to try and pi...
- Thu Aug 17, 2023 12:46 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Aligning heat "vectors"
- Replies: 25
- Views: 17361
Re: Aligning heat "vectors"
One experiment that I have yet to get around to, is de-coupling the displacer from the power piston, and therefore having two flywheels, one driven by the piston, and driving the load; the other driven by an electric motor and driving the displacer. It seems likely to me, that this would automatical...
- Thu Aug 17, 2023 12:38 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: if stirling engine is driven as reversed, does it work as cooler?
- Replies: 94
- Views: 48851
Re: if stirling engine is driven as reversed, does it work as cooler?
Tom, There is no such thing as a vacuum - the word is a useful concept, but in reality there is no such thing as a negative gas pressure. We would be in trouble if there were, as all of Earth's atmosphere would be sucked out into space. All of the demonstrations of a can/bottle/whatever imploding ar...
- Mon Aug 14, 2023 4:59 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: if stirling engine is driven as reversed, does it work as cooler?
- Replies: 94
- Views: 48851
- Fri Aug 11, 2023 2:55 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Displacer hot space vs cold space study
- Replies: 19
- Views: 3309
Re: Displacer hot space vs cold space study
In your spreadsheet diagram, do the purple sections indicate dead-space?
- Wed Aug 09, 2023 4:39 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The Carnot efficiency problem
- Replies: 258
- Views: 119534
Re: The Carnot efficiency problem
Tom, The simple point is that we all know that you cannot get power out of a machine without putting energy in. We can all discuss perpetual-motion as part of understanding the operation of a "perfect" Stirling engine, ie one with zero friction, but "free energy" is a whole 'noth...
- Tue Aug 08, 2023 4:25 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The Carnot efficiency problem
- Replies: 258
- Views: 119534
- Fri Aug 04, 2023 4:08 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The Carnot efficiency problem
- Replies: 258
- Views: 119534
Re: The Carnot efficiency problem
Tom, It seems to me that a very simple experiment is possible, and hopefully useful, which is to de-couple the displacer from the piston of a suitable engine - probably by connecting a second flywheel. My question was meant to be somewhat rhetorical, and based round logical thought experiments but p...
- Thu Aug 03, 2023 7:14 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The Carnot efficiency problem
- Replies: 258
- Views: 119534
Re: The Carnot efficiency problem
Goofy, What is the point of the displacer? Is it needed?
- Thu Aug 03, 2023 2:28 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The Carnot efficiency problem
- Replies: 258
- Views: 119534
Re: The Carnot efficiency problem
Goofy - the problem is this: If for a moment, we ignore the "work done" on/by the piston, then what keeps the motor running? The simple answer is the alternating change in pressure of the working gas. What causes that change in pressure? The smaller reason is change of volume from the pist...
- Thu Jul 20, 2023 11:21 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The Carnot efficiency problem
- Replies: 258
- Views: 119534
Re: The Carnot efficiency problem
The "Cloud in a bottle" demo - it's not really an experiment - is largely a demonstration of the rather surprising properties of humidity and vapour saturation, not of temperature directly. The cloud forms because the loss of pressure moves the dew-point. (I've seen it done much more impre...
- Mon Jul 17, 2023 7:01 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The Carnot efficiency problem
- Replies: 258
- Views: 119534
Re: The Carnot efficiency problem
Tom,
The problem with treating ambient as being equivalent to zero, is 'pressure' doesn't agree with that at all - gas pressure at 300K is 75% of that at 400K (for the same volume) ...
The problem with treating ambient as being equivalent to zero, is 'pressure' doesn't agree with that at all - gas pressure at 300K is 75% of that at 400K (for the same volume) ...