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Fool wrote: ↑Wed Oct 09, 2024 11:53 am Friction is not a derail. Your banter is.

There is nothing in the topic heading about "friction", related to "friction" or concerning "friction" at all. Your persistent insistence it is somehow a central aspect or element in JT throttling is the derail.

JT has everything to do with intermolecular attraction and repulsion and nothing to do with friction.

And your still a moron.

If the gas molecules have perfectly elastic collisions and are moving at the speed of sound, do they even have time for friction?

Though the viscosity of air does increase with temperature due to increased molecular movement, does that mean more friction or just more impacts? As far as I know the only result of this friction could be static electricity or lightning perhaps.

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Viscosity is what causes friction. The ideal gas model has no viscosity. No friction no JT effect. Friction is in gas flow, not intermolecular collisions. Static pressure has no friction. It is fluid dynamic not thermodynamic. No viscosity no drag. No flow not JT. Slow flow slow JT. Wide open channels no JT. The whole idea in a Stirling engine is to maximize pressure. JT requires a pressure drop. Maximizing JT requires maximizing pressure drop.

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https://en.m.wikipedia.org/wiki/Viscosity

https://en.m.wikipedia.org/wiki/Joule%E ... son_effect

The following graph is from that last link.


In the upper right corner, where our engines operate, about 300 K, higher temperatures are worse, pressure goes from 20 bars to 1 bar and lower, there is a maxim JT effect of about 5 K ∆T. Or 10 F. Way way less at 5 bars.

I'm not sure what you plan to do with 1 C, let alone how losing 5 bars of pressure to get any effect at all. It goes from 75 psi to zero to get 1 F or less. Losing all the pressure for 1 F can't be beneficial to driving a piston.

As I said at the beginning, JT effect is for open expansion, not driving a piston. Sorry, I don't see any viable direction for any gains especially enclosed in an engine.

Good brainstorming.

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Fool wrote: ↑Wed Oct 09, 2024 5:08 pm ....
I'm not sure what you plan to do with 1 C, let alone how losing 5 bars of pressure to get any effect at all. It goes from 75 psi to zero to get 1 F or less. Losing all the pressure for 1 F can't be beneficial to driving a piston.
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You don't have a clue.

Joule -Thompson cooling is often fractional in its effect.

That is, a fraction of a degree.

Say 0.001°C per cycle

1° in 1000 cycles maybe.

In an engine running at 3000 RPM that could be 3°/minute. 15° in five minutes etc.

In 20 minutes you've increased the ∆T by 60°

How do you think JT is used to liquefy gases down to cryogenic temperatures? ass hole.

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Tommy wrote:You don't have a clue.

I wouldn't have asked the question if I knew the answer. Please explain. Explain exactly how it's to be done? And how it will be beneficial?

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VincentG already made that clear early on. If you weren't so full of yourself you might have noticed.

VincentG wrote: ↑Wed Oct 02, 2024 6:46 am

Tom Booth wrote: ↑Tue Oct 01, 2024 11:03 pm So, if you heat a gas to the inversion temperature, add a little more heat and expansion will be assisted by the gases molecular repulsion.

Cooling it below the inversion temperature will assist compression due to the gases own molecular attraction.

Maybe?

That's the theory. I think I have a way to test this directly and experimentally but don't think it's worth the time for me. The proof would be in an engine running at greater than expected efficiency.

"So, if you heat a gas to the inversion temperature, add a little more heat and expansion will be assisted by the gases molecular repulsion."

Again expansion in a piston cylinder is with work. It will only be an internal energy reduction from expansion. Zero JT effect. JT effect comes from zero work expansion. If adiabatic, it will only have a detrimental temperature decrease from work output.

If expanded before the piston moves pressure will drop completely for exchange of a degree C. How are you going to push the piston with zero pressure?

"Cooling it below the inversion temperature will assist compression due to the gases own molecular attraction."

There is no such thing as JT compression. If adiabatic it will have a detrimental temperature increase from work input.

Again: Please explain. Explain exactly how it's to be done? And how it will be beneficial? Use the graph if you know how.

I don't understand. Do you? If you don't know, don't explain it here. Definitely doesn't appear worth anyone's time.

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Fool wrote: ↑Wed Oct 09, 2024 11:08 pm

VincentG wrote: ↑Wed Oct 02, 2024 6:46 am

Tom Booth wrote: ↑Tue Oct 01, 2024 11:03 pm So, if you heat a gas to the inversion temperature, add a little more heat and expansion will be assisted by the gases molecular repulsion.

Cooling it below the inversion temperature will assist compression due to the gases own molecular attraction.

Maybe?

That's the theory. I think I have a way to test this directly and experimentally but don't think it's worth the time for me. The proof would be in an engine running at greater than expected efficiency.

"So, if you heat a gas to the inversion temperature, add a little more heat and expansion will be assisted by the gases molecular repulsion."

Again expansion in a piston cylinder is with work. It will only be an internal energy reduction from expansion. Zero JT effect. JT effect comes from zero work expansion. If adiabatic, it will only have a detrimental temperature decrease from work output.

If expanded before the piston moves pressure will drop completely for exchange of a degree C. How are you going to push the piston with zero pressure?

"Cooling it below the inversion temperature will assist compression due to the gases own molecular attraction."

There is no such thing as JT compression. If adiabatic it will have a detrimental temperature increase from work input.

Again: Please explain. Explain exactly how it's to be done? And how it will be beneficial? Use the graph if you know how.

I don't understand. Do you? If you don't know, don't explain it here. Definitely doesn't appear worth anyone's time.

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In your obsolete strictly "ideal gas" delusional "classical thermodynamics" world there is no such thing as the Joule-Thomson effect, so I don't expect you to understand, so why don't you shut up about your BS "friction" theory, stop derailing the thread and let VincentG get on with it.

There is no such thing as JT compression

Cooling a gas allows the gas to more easily contract during compression.

VincentG is pioneering in new uncharted territory. Naturally you aren't going to find anything about it in a Google search.

Tom brings up the most relevant point, that the JT effect is insignificant or dismissed when considering an ideal gas. I have read in many places explaining the JT effect, that my air tank does not drop to freezing temperatures when the valve is open from only 10 bar.

As I said at the beginning, JT effect is for open expansion, not driving a piston. Sorry, I don't see any viable direction for any gains especially enclosed in an engine.

As I mentioned it may only help during the period of PP dwell at TDC. But realize the gas is always in "open expansion" to some degree, or the engine would not run at all.

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VincentG I already acknowledged that the JT effect requires viscosity. Ideal gasses have no viscosity. What more do I need to say. This has nothing to do with ideal gasses.

Tommy is injecting a straw man into this thread because he either is a paid troll or ignorant of how to logically and politely discuss something. Sorry he has done so. It was my attempt to point out the simple errors in your brainstorming. He's the one that put forth the lies. Anyway, my points are still valid. Please consider them for your own benefits. Ignore Tommy he is so often wrong and more often vile when his errors are pointed out.

Tommy, your first comment is far from the truth. I know way more than you give anyone but yourself credit. You are the uneducated here. So much so that any educated scientist sees right through your experimental flaws. Your refusal to make the simple measurements required means you know it and are deliberately avoiding gathering that evidence. For all we know you already have discovered your error and refuse to disclose it. How is your butane refrigerator going? My guess is you failed and now won't tell us that Fool knows more about refrigerator scams than you. Imagine knowing less than this Fool.

Tommy wrote:Cooling a gas allows the gas to more easily contract during compression.

Yes cooling, implying the rejection of heat by a temperature difference through conduction, before and during compression makes compression easier. Smartest thing you've said in a long time. Except gas doesn't "contract" it always fills the cylinder with positive pressure, requiring force outside the cylinder to compress it.

VincentG is on a wild goose chase and suggesting/requesting help from us on an effect that is non-existent inside any enclosed heat engine. I've given that help. He is daydreaming. An okay process for brainstorming. It is not pioneering unless he has a demonstrable machine or theory. Theorizing requires data and complete logical connection to other theories, brainstorming doesn't. He said it was not worth his time to pursue it, but proof would be that it breaks the second law. A circumvention of the second law, would allow a perpetual motion machine of the second kind. Again, that breaks concurrently the first law.

Friction is your diversion Tommy. I'm pointing out that the idea is counterproductive, with or without friction, drag, orifice, or capillary tube. Expanding the gas without work so it can be compressed more easily is an oxymoron at best. But I point out, it will have expanded, loss of energy, with little if any temperature change, so little regain if any. Easy to see if you know how to read the graph I supplied. And it will then take more energy to compress, destroying and hope of improvement. Proof will be that it runs less efficiently.

But you all, don't let knowledge get in your way of a fun inspiring waste of all the loads of free extra time we all have built up just to use on a wild greased goose chase. Please have fun. While you are at it, put grinding powder on the piston so the friction will add to the 'heat of expansion', so that more heat can be converted to work, making the engine run even cooler so it never needs to reject heat, or absorb any either. Self heating is the way to go. Which is what you all are insinuating with the breaking of the second law. Self cooling implies self heating can be done. Bollocks.

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Fool wrote: ↑Thu Oct 10, 2024 5:51 am ...

Tommy wrote:Cooling a gas allows the gas to more easily contract during compression.

Yes cooling, implying the rejection of heat by a temperature difference through conduction,

No, stop taking my words out of context. We are discussing the Joule-Thomson effect here, obviously above your head.

Except gas doesn't "contract" it always fills the cylinder with positive pressure, requiring force outside the cylinder to compress it.

Ho hum. Your like a broken record.

JT throttling will ultimately cause a gas to "contract" and liquefy in a Linde gas liquefaction machine after "expanding" through a JT valve into a partial vacuum. No compression. Just mutual attraction (of the gas molecules. The same thing that causes the gradual cooling from JT in the first place.

You are ignorant and wasting people's time trying to derail VincentG's thread. VincentG's idea has a lot of merit.

VincentG is on a wild goose chase ... it breaks the second law. A circumvention of the second law, would allow a perpetual motion machine of the second kind. Again, that breaks concurrently the first law.

You mean, just like the JT valves in heat pumps, air conditioners, refrigerators and freezers etc. with COP's > 1 ?

So what if it does?

Charles Tripler reported he could liquefy 10 gallons of liquid air by running his air liquefaction machine on three gallons of the liquid air he continually produced.

Like many others, his livelihood was ruined, by closed minded 2nd Law fanatics like you "fool".

VincentG is on a wild goose chase and suggesting/requesting help from us on an effect that is non-existent inside any enclosed heat engine. I've given that help. He is daydreaming. An okay process for brainstorming. It is not pioneering unless he has a demonstrable machine or theory. Theorizing requires data and complete logical connection to other theories, brainstorming doesn't. He said it was not worth his time to pursue it, but proof would be that it breaks the second law. A circumvention of the second law, would allow a perpetual motion machine of the second kind. Again, that breaks concurrently the first law.

I think you'd be surprised how little time I spend on all this. If we can agree that the real-world JT effect is greater than the chart, than what's the point of posting it? I'm not sure where I said perpetual motion or self heating, or anything about breaking the second law.

All I'm suggesting is that the inversion temperature seems to imply that at some point the internal energy of the gas is able to express itself in a way that is more useful to us. I have just within the past two weeks or so learned of this inversion temperature effect and it seems to be the answer to a question I've had for a long time now.

As an aside, like many other things, the meaning of "a wild goose chase" has been lost to history. https://nosweatshakespeare.com/quotes/f ... ose-chase/

A timely tangent, as I have recently been thinking that if some of these guys (like Boltzmann) were still around, we could see the continuation of their efforts. Perhaps some of their later, or unpublished work had some key insights that were also lost to history.

VincentG wrote: ↑Thu Oct 10, 2024 7:42 am ...
I'm not sure where I said perpetual motion or self heating, or anything about breaking the second law.
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Of course you didn't. It's just "fools" bugaboo he has to obsessively warn everybody away from.

IMO research should be unfettered by past assumptions.

Tom Booth wrote: ↑Thu Oct 10, 2024 8:26 am

VincentG wrote: ↑Thu Oct 10, 2024 7:42 am ...
I'm not sure where I said perpetual motion or self heating, or anything about breaking the second law.
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Of course you didn't. It's just "fools" bugaboo he has to obsessively warn everybody away from.

IMO research should be unfettered by past assumptions.

All I ever set out to do is build a functional Stirling engine for my own use.

For some reason such an endeavor attracts 2nd Law fanatics like horse flies obsessively trying to thwart any incremental progress or advance. It's like some kind of fanatical religious cult. At least one on every forum.

If not paid shills, just a bunch of brain damaged idiots. There is no parallel.

In any other branch of science people are free to pursue their research wherever it may lead, but when it comes to anything involving energy production you will have to deal with these paid or self appointed guardians of the status quo.