LTD model "Stirling" uses Lenoir Cycle

[Tom Booth]

Anyone who sits outside long enough will "observe" that the sun appears to go around the earth, but (nearly) everyone knows that the earth goes around the sun. Hmmm, why do so many guys believe the latter, when so few can prove this (and the proof ain't rocket science).

Why did some refuse to look through Galileo's telescope ?

Random reference: https://www.libraryofsocialscience.com/ ... lileo.html

[Nobody]

One reason that some of those refused a look, could very well be: Staunch belief. Belief is bad. It proves nothing yet keeps people from learning. The first thing belief destroys may be one's own healthy skepticism. Eventually it could lead to destroying lives.

If those that denied themselves a new viewpoint/investigation, by refusing a look through it, had approached with skepticism of the points of light in that telescope, they could have used the device to view mountain climbers or sheep or lost herds, while claiming skepticism on the initial conclusions of Galileo. Instead, their incapacitating beliefs branded the device evil, so it became useless to them.

Of course if they'd had healthy skepticism of all books, including one self claiming to be God's word, they would not have feared looking through a simple tube with glass on each end, in first place. And that would have led to stronger more powerful telescopes hundreds of years earlier.

Yes, Skill and Daring overcome: Belief, Fear, and Intimidation. *

Dare to be skeptical.
Study and explore to become skillful.

* Words of wisdom from a ship's Chief Engineer. Modified by me. The rest of my words here are all me. I know of no one else that has worded them.

[matt brown]

Dare to be skeptical.
Study and explore to become skillful.

20 yrs ago, I solved an ECE 'problem' that I'd been chasing for 15 yrs. (the final solution took a stroke of luck). However, after I solved the problem, I could only express the solution via general math in a simple xyz format. When I shared this with a guy who taught thermo at Penn St., he kinda went off on me, and tested my goofy little equation which explained my 'magic' solution. He quickly concluded that my simple math appeared correct, but he thought it was still too fuzzy (no limit constraints). So, the good Prof. wouldn't give me the nod until I could express the magic in a more coherent form.

After 15 yrs. of daydreaming AND finally solving my chase, I thought OK, this shouldn't be too hard. Now remember, I said simple xyz format, and it was, and most school kids would have given me the nod. But, it would take me nearly 2 more yrs. to achieve a 'coherent' form and my 'trick' was amusing: I simply went from algebraic yadda-yadda-yadda = 0, to pre-algebraic yadda-yadda-yadda = 1, whereupon everything fell into place.

For those that aren't students of math history, I borrowed from the ancients...where Greek/Egyptian/etc "1" predates algebraic "0" and base 10.

[Nobody]

You just created something "1" from nothing "0". LOL

[Nobody]

Ivo Kolin:

Page 69, Lehmann Engine:

Effective power 1 hp
Indicated power calculated from diagrams 1.515 hp
Mechanical efficiency 1/1.515 = 66%

Carnot is not discussed in the page, but I point it out here:
Nc = 1 - Tc/Th = 1-373/623 = 0.562 or 56%

Put in the mechanical losses:
66% of 56% 56 x .66 = 36.96%

Expect that engine to get less than 37% fuel conversion.

Actual fuel conversion, from the bottom of the page:

4% <<<<<

The book is filled with engines getting way less than the Carnot limit. Just one example out of all the engines in the book. None of the engines come even close to the Carnot limit. I hope you see this as evidence for putting the Carnot limit to rest.

When you put forth a solid theory that predicts accurately fuel conversion to power out for a Stirling Engine, you will become well known. "The Booth Equation", of course Nobody could beat you to it.

No one has an equation that will do that. Carnot tried, but, it greatly over shoots actual engines. Very good for a two hundred years old prediction.

The Schmidt theory undershoots it.

Good luck and engineering.

[Tom Booth]

It is not surprising that the Lehmann engine would have very low efficiency.

It has the typical disadvantages of a cold side dead air space (green arrow) and an incredibly long displacer chamber with enormous active cooling jacket circulating cold water. (Blue arrows).

Resize_20220320_103442_2379.jpg (105.2 KiB) Viewed 3145 times

The problem IMO is a belief/philosophical one.

In the mid 1800's the idea of heat as Caloric still dominated heat engine theory, (as it still does today, actually, if only unconsciously) which assumes the necessity of removing the heat applied at one end with equivalent cooling at the other end.

Following the Carnot ideology in engine design is the actual cause of the inefficiency. The cooling jacket has probably at least 5X the surface area of the heating area

This is no doubt based on the Carnot idea that all that matters is having as large a temperature difference as possible, so the more cooling applied the better.

[Nobody]

I can see you have the belief that, only you are correct. The green arrow you have placed in the above drawing is pointing at the cold space. That is an area of overlap of the piston and displacer. In engineering terms part of the working volume of the engine. Not ever called dead space. Zero when the piston and displacer all but touch.

You appear to be alluding to the idea that a working volume designed for cooling isn't needed for pressure differential. Therefore you are calling the cold space dead. I'm skeptical that is likely to work, or be convincing.

Without a cold space, you will have nothing for your hot gas to expand into, whether that cold is created by expansion or provided by outside means.

Furthermore without a cooling system, your expansion space will absorb some of, the heat of compression and heat from friction. Effectively making your engine an air spring, and it's indicator diagram will follow the same adiabatic path for expansion and compression, and produce zero taxable work. Any attempt to extract work will just stop the bounce.

Air springs are not fully adiabatic. Compression heats the gas and the cold walls begin absorbing heat. Expansion cools the gas and the warmer walls start adding heat. That makes an air spring loose input work to the ambient every cycle. Probably why they only bounce a few times before stopping.

Senft in his book "Low Temperature Difference Stirling Engines" on page 46 says "Engines rarely reach half of their Carnot efficiency potential..."

It is very brash to exclaim that, you know it is because of a flawed engineering concept, when you don't have an engine to demonstrate, let alone having the engineer education necessary to understand these things. I'm hear to help. Slow down. Learn more. Be skeptical. Listen to your peers. Investigate. Be daring. The cold space won't go away because we wish it away.

Efficiency isn't even all that important as a design criteria. In other words I don't care if Carnot is wrong or right.

[Tom Booth]

I can see you have the belief that, only you are correct. The green arrow you have placed in the above drawing is pointing at the cold space. That is an area of overlap of the piston and displacer. In engineering terms part of the working volume of the engine. Not ever called dead space. Zero when the piston and displacer all but touch.

You appear to be alluding to the idea that a working volume designed for cooling isn't needed for pressure differential. Therefore you are calling the cold space dead. I'm skeptical that is likely to work, or be convincing.

Without a cold space, you will have nothing for your hot gas to expand into, whether that cold is created by expansion or provided by outside means.

Furthermore without a cooling system, your expansion space will absorb some of, the heat of compression and heat from friction. Effectively making your engine an air spring, and it's indicator diagram will follow the same adiabatic path for expansion and compression, and produce zero taxable work. Any attempt to extract work will just stop the bounce.

Air springs are not fully adiabatic. Compression heats the gas and the cold walls begin absorbing heat. Expansion cools the gas and the warmer walls start adding heat. That makes an air spring loose input work to the ambient every cycle. Probably why they only bounce a few times before stopping.

Senft in his book "Low Temperature Difference Stirling Engines" on page 46 says "Engines rarely reach half of their Carnot efficiency potential..."

It is very brash to exclaim that, you know it is because of a flawed engineering concept, when you don't have an engine to demonstrate, let alone having the engineer education necessary to understand these things. I'm hear to help. Slow down. Learn more. Be skeptical. Listen to your peers. Investigate. Be daring. The cold space won't go away because we wish it away.

Efficiency isn't even all that important as a design criteria. In other words I don't care if Carnot is wrong or right.

Right, Tom Booth is unlearned and illiterate. Good argument.

As I said before, I have several engines that clearly demonstrate the lack of necessity for a cold side "sink". Simply take an ordinary Stirling engine and decommission the sink by exchanging material; use an acrylic (non conducting/insulating) cold plate, instead of a highly conductive metal plate. Insulate the cold heat exchanger from the surrounding ambient "sink". etc.

Certainly these experiments can be taken further, but I've personally seen more than enough to convince me that a heat engine actually runs better and more efficiently if the heat is conserved as much as possible rather than being intentionally dissipated to a sink or massive cooling jacket.

Replace the cold water cooling jacket with an insulating material to retain heat in the Lehmann Engine and it will run much better. A radically new engine design is not what is particularly needed. What is needed is different design practice. Stop throwing heat away needlessly. Stop designing with HEAT REMOVAL as the end goal rather than heat utilization/conversion for power output.

[Nobody]

I am skeptical. I've reviewed your experiments and have commented in other threads. Take your test fixtures to a university. Demonstrate them. Maybe they'll give you an honorary degree. I'd help you myself if I lived in the New York area.

Tom said:
"Right, Tom Booth is unlearned and illiterate. Good argument."

I wouldn't say that at all. A High School Teacher told me it doesn't matter what you know, people listen more if you can claim a degree. It convinced me to push through despite what they were teaching and expecting. I learned a lot more because of it, and would love to go back and learn more. You can't expect to learn what we ignore.

[Tom Booth]

...

Tom said:
"Right, Tom Booth is unlearned and illiterate. Good argument."

I wouldn't say that at all. A High School Teacher told me it doesn't matter what you know, people listen more if you can claim a degree. It convinced me to push through despite what they were teaching and expecting. I learned a lot more because of it, and would love to go back and learn more. You can't expect to learn what we ignore.

I was being facetious. Ad hominem is never a good argument, but you resort to it continually.

[Nobody]

With an engineering degree people assume a basic education. Without one we are in the dark. If we are in the dark and someone denounces standard engineering education, we need superior data and procedures to overcome the difficulties. I see lots of simple errors that would be avoided. I can't easily explain them without a similar knowledge base.

Similar to the scheme to generate 24 Volts to run a 12 Volt motor to make over unity free energy. Ignorant of Watts, Amperes and Ohms.

[matt brown]

You just created something "1" from nothing "0". LOL

I've always had a weird fascination with math. No, not calculus and the fancy stuff, but the 'goofy' first principle/s stuff. When I was in high school (early '70s) and many guys were absorbed with the Fischer-Spassky showdown, I was absorbed by a Nobel Prize nominee for his paper on the theory of 0 and 1. Later, my warped math interest came in handy during the rise of computers, but I stuck with the hardware nerds vs the software geeks. Looking back, I was in the right place at the right time (again) when early computers moved into color graphics driven by the 'magic' of codecs and RAMDACS, and I was helped along by an early interest in cryptography which stemmed from a childhood fascination with the 1860's Andersonville code.

I grew up where everyone dares to dream the impossible of making something from nothing...the SoCal coast between Hollywood and Disneyland. It's not La-La Land due to beautiful weather and girls, but a dreamscape with a fuzzy reality due to rarified air...the car culture, the entertainment ind, the sports ind, the fashion ind, aerospace, electronics, etc.

Sucking this La-La air 24/7 for decades can never be replicated, and is best described by the Eagles "you can check out anytime you like, but you can never leave"...

[matt brown]

Similar to the scheme to generate 24 Volts to run a 12 Volt motor to make over unity free energy. Ignorant of Watts, Amperes and Ohms.

Kudos !!! I've often thought this while pecking away on keyboard, along with what's next, explaining E=mc^2

I'm clueless why most people know Einstein's eq, since it's largely useless info (and we'd all be better off without it).

[Tom Booth]

...The green arrow you have placed in the above drawing is pointing at the cold space. That is an area of overlap of the piston and displacer. In engineering terms part of the working volume of the engine. Not ever called dead space. Zero when the piston and displacer all but touch.

...

Ok, I misinterpreted the canister as a displacer chamber only, and the piston on the end as simply the chamber wall.

Your calculations and interpretations of efficiency look doubtful however.

You don't actually cite (quote) the text, instead you insert your own Carnot efficiency values/equations apparently reinterpreting the passage to your liking with no context.

Ivo Kolin:

Page 69, Lehmann Engine:

Effective power 1 hp
Indicated power calculated from diagrams 1.515 hp
Mechanical efficiency 1/1.515 = 66%

Carnot is not discussed in the page, but I point it out here:
Nc = 1 - Tc/Th = 1-373/623 = 0.562 or 56%

Put in the mechanical losses:
66% of 56% 56 x .66 = 36.96%

Expect that engine to get less than 37% fuel conversion.

Actual fuel conversion, from the bottom of the page:

4% <<<<<

So you use Carnot efficiency as your starting point, then deduct mechanical loses from there, which seems like circular reasoning.

The Carnot efficiency equation is what is in question so you cannot use Carnot efficiency to prove Carnot efficiency

[Tom Booth]

The Lehmann engine looks like it could have been very efficient, except that the hot expanding gas, in order to reach the piston, must travel through long narrow passages of cold steel surrounded by cold circulating water.

So 96% of the heat from the fuel being burned is either going up the chimney, or absorbed and dissipated into cold steel/water.

That does not prove that the 4% heat actually entering into and expanding the working gas is limited to Carnot efficiency in it's conversion to work.