The inversion temperature of gas and its role in hot air engines

[Tom Booth]

In theory you could have an orifice that is frictionless. JT would be the same.

You are the one accusing people you disagree with of "intentional lying". So grow up yourself.

Throttling is only a means of holding back the gas to maintain pressure. JT has nothing to do with the negligible friction at the edges of the orifice. It has to do with the pressure drop and freedom of the gas molecules to expand in a lower pressure environment not any friction encountered in the passage.

Further, what influence could any friction at a throttling orifice have on the mechanical aspects of the operation of the engine?

[VincentG]

Throttling is only a means of holding back the gas to maintain pressure. JT has nothing to do with the negligible friction at the edges of the orifice. It has to do with the pressure drop and freedom of the gas molecules to expand in a lower pressure environment not any friction encountered in the passage.

Further, what influence could any friction at a throttling orifice have on the mechanical aspects of the operation of the engine?

As Matt has found, the same engine operating at different temperatures is in effect a different engine all together.

I'll go on to say the same Gamma chamber, operating at the same temperatures, but with a different gas flow path to the piston, is a different Gamma chamber all together.

When the chamber is allowed to operate with no significant restriction, it is not operating efficiently (like the Essex). The chamber needs to be briefly sealed to allow the gas to heat at Cv before the gas acts on the piston. If there is a possibility of an inverse JT effect upon expansion, it's likely to be a delicate dance. The gas may need to be funneled through a well-designed and heated expansion nozzle. Maybe any excess friction will alter the desired effect here. Something like a de Laval nozzle comes to mind.

[Fool]

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You are the one accusing people you disagree with of "intentional lying". So grow up yourself.

I hope I have not accused anyone of intentionally lying, unless they are intentionally lying. Accusing someone of a lie is not intended to be the same as accusing them of an intentional lie. If I've done so, I apologize. I hope, if I've done so, it is towards those that misstate my posts, as you frequently do, including, IMHO, the above comment about lying. I think what I was implying is that intentional lying is bad, and should be corrected. Misunderstood concepts is also bad and should be corrected. Errors should be corrected. Being corrected is good for everyone, except an intentional liar, or a narcissist.

Throttling in fluid dynamics is installing a drag device into a conduit. Drag is fluid dynamic friction. I thought you'd have learned this in college class.

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[Tom Booth]

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You are the one accusing people you disagree with of "intentional lying". So grow up yourself.

I hope I have not accused anyone of intentionally lying, unless they are intentionally lying. Accusing someone of a lie is not intended to be the same as accusing them of an intentional lie. If I've done so, I apologize. I hope, if I've done so, it is towards those that misstate my posts, as you frequently do, including, IMHO, the above comment about lying. I think what I was implying is that intentional lying is bad, and should be corrected. Misunderstood concepts is also bad and should be corrected. Errors should be corrected. Being corrected is good for everyone, except an intentional liar, or a narcissist.

Throttling in fluid dynamics is installing a drag device into a conduit. Drag is fluid dynamic friction. I thought you'd have learned this in college class.

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You misunderstand the terminology and purpose of a throttling device and have it backwards.

A "throttle" is a restriction. Look up the definition:

A throttling device restricts flow. That is all.

A long capillary tube is a type of throttling device that .makes use of "friction" as a primary means of restricting flow, but the friction is only a means to an end and that is to hold back pressure in the condenser and allow the compressor/vacuum pump to create a vacuum in the evaporator. Friction at a simple orifice, a different type of restriction or throttling device is negligible, as it is in many other types of throttling devices, expansion valves etc.

At any rate, any friction is beside the point. Even in a capillary tube friction is only a means to an end.

A throttling device is not necessarily a "drag device". A long capillary utilizes drag as one means of throttling. And creating friction is not the purpose of any throttling device, though some throttling devices use friction as a means for restricting flow.

A dam on a river is a "throttling device". The point being that the dam restricts the flow of the river allowing the water level to rise on one side and lower on the other.

That there is some friction at the spillway is entirely beside the point and incidental to the purpose of the dam, just as it is incidental to Joule-Thomson throttling.

[Fool]

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When the chamber is allowed to operate with no significant restriction, it is not operating efficiently (like the Essex). The chamber needs to be briefly sealed to allow the gas to heat at Cv before the gas acts on the piston.

I'm not sure why it would be inefficient to have no restrictions? Maybe I misunderstood.

Having the DC come up to full temperature/pressure before starting an expansion stroke would be a good thing. Complicating an engine with a valve, or a delay in motion would need to have a sufficiently large gain in efficiency or power to warrant it.

A valve to retime any JT advantage would probably give minimal benefit, as the restriction of flow would have negative pumping loss effects, and a wider orifice would have less JT effect. And the little pressure difference between displacer chamber and piston, would make the effect very minimal. JT depends on a high pressure drop.

Remember JT requires a pressure drop. To get that pressure drop by throttling the gas coming from the DC to the PP would just reduce the pressure acting on the piston.

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[Fool]

A throttle, orifice, capillary tube, and pours plug, are all throttling processes. The all work by producing drag.

[Fool]

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From Wikipedia:

https://en.m.wikipedia.org/wiki/Enthalpy#Throttling

One of the simple applications of the concept of enthalpy is the so-called throttling process, also known as Joule–Thomson expansion. It concerns a steady adiabatic flow of a fluid through a flow resistance (valve, porous plug, or any other type of flow resistance) as shown in the figure.

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[Tom Booth]

A throttle, orifice, capillary tube, and pours plug, are all throttling processes. The all work by producing drag.

You can say so, but "drag" does not CAUSE the Joule-Thomson effect.

The Joule-Thomson effect was originally an experimentally observed phenomenon. A deviation from expected "ideal" gas behavior with no immediate explanation or known cause.

From what I've seen, current theories vary. The most widely accepted theories make no mention whatsoever of friction or "drag" as a relevant factor in the Joule-Thomson effect. But who really knows? I very much doubt "fool" has nailed it down with his friction/drag theory.

You still haven't explained how "friction" or "drag" in JT throttling causes cooling of the gas under certain conditions but heating under other conditions.

Oh, I forgot, you, as usual are flip flopping on the issue when pinned down:

Fool:

I didn't say it was caused by friction. I said friction is necessary. It is the sudden expansion after the friction that allows the molecules to interact. Not intermolecular friction. Skin friction.

Not that that actually makes any real coherent sense. Just diversionary mealy mouth BS. Avoidance of the central issue.

In this random example video, just for example, there is no mention of friction, drag, the amount of friction, the length, width or narrowness of the passage. All largely irrelevant to JT

https://youtu.be/Y-fZxwZZkyI

Please provide some similar supporting resources for your "friction is NECESSARY" for Joule-Thomson theory.

An orifice or passageway can have variable "friction" or "drag" from great as in a capillary tube to virtually none. The type of orifice or throttle or valve and the amount of friction has no bearing on JT. Does not alter the chart. Is not a "necessary" or relevant factor.

Sure, friction MAY exist and have some influence, but that is incidental to JT.

[Tom Booth]

Next you'll be saying: uh, I didn't say friction was necessary, just that,... blah blah blah,.. who knows what you'll come up with.

I just think your criticism is baseless and unwarranted.

Just like your insinuations people are "intentionally lying".

I hope I have not accused anyone of intentionally lying, unless they are intentionally lying. Accusing someone of a lie is not intended to be the same as accusing them of an intentional lie

Your double talk doesn't get you off the hook.

[Tom Booth]

This is your statement:

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The JT effect requires thermodynamic friction, called 'throttling'.

Wrong!

There is no such equivalence. Friction is not "called 'throttling'" by anyone, but some "fool". If so provide a reference or admit you're full of shit

The friction is in the form of: an orifice:

Nonsense. Friction does not have the "form" of an orifice.

capillary tube: semi poris material: ETC...

These are not "forms" of friction.

Yes it is mechanical thermodynamic friction. No it is not kinematic friction.

".mechanical thermodynamic friction" vs. "kinematic friction"

You don't know what your talking about, are misusing terminology and just talking nonsense.

I don't see how pointing out classical theory is picking on anyone but intentional liars.

Bingo.

You insinuate all who do not agree with your twisted incoherent, nonsensical rendition of "classical theory" are, in YOUR WORDS: "intentional liars".

Your a fat headed arrogant moron who doesn't know classical thermodynamics from a hole in the wall and can barely formulate a coherent sentence. Think your moronic opinions constitute infallible math and science.

A troll who should have been banned a long time ago, and would be if the owner/moderator were still around.

[Fool]

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Your Google AI has this to say:

Yes, a fluid throttle is a friction device because the friction between molecules of the fluid slows down the flow as it passes through the valve:

All that whining and stomping your feet must really hurt now that you can't go running to a moderator with your lies to get someone band. If my only crime is to point out errors, and not know anything, at least I'm out smarting you.

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[Tom Booth]

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Your Google AI has this to say:

Yes, a fluid throttle is a friction device because the friction between molecules of the fluid slows down the flow as it passes through the valve:

All that whining and stomping your feet must really hurt now that you can't go running to a moderator with your lies to get someone band. If my only crime is to point out errors, and not know anything, at least I'm out smarting you.

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That says nothing about Joule-Thomson.

Yes, all known throttling devices, as far as I know, have SOME friction. That does not mean the Joule-Thomson effect is in any way a result of, or dependent upon the existence of friction in a throttling device.

Your AI reference does not prove the Joule-Thomson effect "requires" friction, as you stated.

A major aspect of a "restriction" is the solid portions or "wall" that blocks flow and does not create friction. The wall of a dam blocking the flow of a river. The friction of some water passing over the spillway of a dam is negligible and has no bearing or importance as far as the function of a dam.

Likewise, any friction that may be associated with a Joule-Thomson throttling device is irrelevant and inconsequential to the function and purpose of that device and has little if any effect or consequence.

Your previous post here:

viewtopic.php?p=25491#p25491

Idiotically and ignorantly and erroneously with critical words such as 'I'm not exactly sure what you expect to gain from friction?" implies that the (negligible) friction that may be associated with the passage of gas through a Joule-Thomson throttling device is all that JT accomplishes and nothing more.

Typical Troll behavior. Baseless criticisms and ridicule of an idea. Uninformed, ignorant and WRONG, as usual. Fool is a pea brain.

[Fool]

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

This procedure is called a throttling process or Joule–Thomson process.

Certainly your full page of vituperation in this case is where the trolling is. I've just reflected classical thermodynamics and fluidynamics.

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[Tom Booth]

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

This procedure is called a throttling process or Joule–Thomson process.

Certainly your full page of vituperation in this case is where the trolling is. I've just reflected classical thermodynamics and fluidynamics.

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No, you have not "reflected classical thermodynamics and fluidynamics."

You've formed a false equivalence between the Joule-Thomson principle and friction.

It's like someone said all automobile tires produce friction on the road and you then conclude that an automobile REQUIRES friction, in principle, to operate.

Your a f-ing boneheaded idiot.

From there you extrapolate that internal combustion in an automobile would be useless because all it would accomplish is producing friction on the road.

Again you've contributed nothing to this topic but a derail with your persistence in your complete idiocy.

[Fool]

Friction is not a derail. Your banter is.