Search found 700 matches
- Tue May 21, 2024 7:24 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 577
- Views: 29050
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Well, "adiabatic" IS without any kind of thermal transfer in or out of the gas. To me that is a less complex scenario than isothermal which for every joule of work done by the gas an equivalent amount of heat is added to replace it. Very true, but my point being that an adiabatic expansio...
- Tue May 21, 2024 7:03 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 577
- Views: 29050
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Tom that was a good response and about sums up what I would ask. By "free expansion", I believe Stroller and I had settled on the baseline of the gas expanding against one atmosphere. So it's still doing "work". I think, for now, thinking in terms of an isothermal expansion is le...
- Tue May 21, 2024 4:20 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 577
- Views: 29050
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
In any example, we would use the minimum amount of gas needed to do the work at hand. By degrades, I mean into a lower temperature state. It's the action of the expanding gas "consuming" energy that I am interested in. Is internal energy really reduced when the gas expands, other than by c...
- Mon May 20, 2024 7:22 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 577
- Views: 29050
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Heat isn't a substance, it's manifested as a flow of energy from a hotter body to a colder body. Energy is neither created nor destroyed, but it can get translated from one thing to another. In our example, the extra Joule started out as additional energy passed from the external energy source into...
- Mon May 20, 2024 3:54 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 577
- Views: 29050
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Regarding the copper verses steel block, I assume it is a weight difference. Just remember moving the displacer up and down is a temperature difference. Although both would move, I would think there would be a difference. I don't know how much. Pressure would be constant for both, but higher for th...
- Mon May 20, 2024 1:25 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 577
- Views: 29050
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Moving to the 5lb weight makes a tremendous systemic difference when the starting pressure rises 4psi from 4 extra pounds across one square inch of piston surface.
I'll think about your response until tonight.
I'll think about your response until tonight.
- Mon May 20, 2024 1:09 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 577
- Views: 29050
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
I thought I had filmed the heavy steel block but I did not. It moved just the same as the copper bar.
https://youtube.com/shorts/WPtcVRK35nU? ... 3tzGUxqpzn
https://youtube.com/shorts/WPtcVRK35nU? ... 3tzGUxqpzn
- Mon May 20, 2024 12:26 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 577
- Views: 29050
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
I'm an engineer, not a forensic nitpicker. I do practical calcs good enough to get the job done, and don't bother about negligible additional forces. That's because nothing ever lives up to its theoretical promise anyway. If you want to know how many millimetres or extra pascals the gas compressed ...
- Mon May 20, 2024 11:55 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 577
- Views: 29050
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
If the starting pressure at 300k and 100cc was 1atm + the added pressure of the 102g piston, it would be a basic pv=nrt calc. But if the temperature of 100cc at 300k and just 14.7psi is doubled to 600k, any additional weight will no longer allow expansion to 200cc. The only way to continue expansion...
- Mon May 20, 2024 10:42 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 577
- Views: 29050
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Often times science is math that cannot be put into words.
In this case, it's words that cannot be put into math?
If I were a teacher I would ask to show your work. And I'm not trying to single you out. I would just like to know.
In this case, it's words that cannot be put into math?
If I were a teacher I would ask to show your work. And I'm not trying to single you out. I would just like to know.
- Mon May 20, 2024 10:13 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 577
- Views: 29050
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Energy required to expand the gas to 200cc AND lift a 1N weight by 1m = 36.5J + 1J = 37.5J
How does the 1J interact with the gas to lift 1N? It seems too simple to just add 1.
Where does the extra Joule go?
- Mon May 20, 2024 7:38 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's "Ambient Heat Engine" Experiment
- Replies: 195
- Views: 193687
Re: Tesla's "Ambient Heat Engine" Experiment
Professional bloviating. Lots of professional bloviating is what I see on here.
- Sun May 19, 2024 6:11 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's "Ambient Heat Engine" Experiment
- Replies: 195
- Views: 193687
Re: Tesla's "Ambient Heat Engine" Experiment
Pretty sure Tom was talking heat of compression, the very basis of diesel ignition.A turbo charged diesel engine uses an intercooler between the compressor and intake to the cylinder.
- Sun May 19, 2024 5:38 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 577
- Views: 29050
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
I understand, but how do we show that extra energy being applied to the gas, mathematically?That will still be 1J. The amount of energy required to lift 1Newton (102g at Earth's surface) through 1meter.
- Fri May 17, 2024 9:56 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Kontax KS90v thermal experiments
- Replies: 6
- Views: 77
Re: Kontax KS90v thermal experiments
With the long tube to power piston I'd bet it would have a better chance at running from heat of hand if the top side was the hot side.
Seems like a good choice for cold bottom and ambient top side.
Seems like a good choice for cold bottom and ambient top side.