Search found 697 matches

by VincentG
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: 566
Views: 28927

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...
by VincentG
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: 566
Views: 28927

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...
by VincentG
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: 566
Views: 28927

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.
by VincentG
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: 566
Views: 28927

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
by VincentG
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: 566
Views: 28927

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 ...
by VincentG
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: 566
Views: 28927

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...
by VincentG
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: 566
Views: 28927

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.
by VincentG
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: 566
Views: 28927

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?
by VincentG
Mon May 20, 2024 7:38 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Tesla's "Ambient Heat Engine" Experiment
Replies: 194
Views: 193648

Re: Tesla's "Ambient Heat Engine" Experiment

Professional bloviating. Lots of professional bloviating is what I see on here.
by VincentG
Sun May 19, 2024 6:11 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Tesla's "Ambient Heat Engine" Experiment
Replies: 194
Views: 193648

Re: Tesla's "Ambient Heat Engine" Experiment

A turbo charged diesel engine uses an intercooler between the compressor and intake to the cylinder.
Pretty sure Tom was talking heat of compression, the very basis of diesel ignition.
by VincentG
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: 566
Views: 28927

Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)

That will still be 1J. The amount of energy required to lift 1Newton (102g at Earth's surface) through 1meter.
I understand, but how do we show that extra energy being applied to the gas, mathematically?
by VincentG
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.
by VincentG
Fri May 17, 2024 6:19 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Replies: 566
Views: 28927

Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)

36.5j for free expansion to 200cc at 600k.

Now how would we calculate additional heat input for the 102g piston in your first example?
by VincentG
Fri May 17, 2024 5:33 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Replies: 566
Views: 28927

Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)

It looks like I goofed my earlier calc by a factor of 10, so it's 36.5J, not 3.65. In the more complex case of joules needed at constant volume, a reasonable engineering approximation would be to multiply the Cv value of air by the mass of air and the change in Temperature. 0.718 x 0.12g x 300 = 25...
by VincentG
Thu May 16, 2024 5:08 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Tesla's Ambient Heat Engine revisted
Replies: 229
Views: 3188

Re: Tesla's Ambient Heat Engine revisted

I have since watched the video. Seems plausible. They make no claims for BTU output, just a temperature reduction. There is certainly an orifice.

I guess one would have to recreate the test to verify.