Sterling Engines
- Thread starter Stephen
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I have very serious doubts that such a device could even be conceived of in the 16th Century.
While Stirling didn't require Carnot's heat cycle theories to develop his heat economizer, his goal in that development was to improve steam engine efficiency enough to make lower operating pressures useful. Putting it another way, Stirling was looking for a way to keep steam engines from blowing up and felt lower operating pressures was one way of achieving that goal.
No steam engines, no explosions, no need to avoid said explosions, no need for an exploration of lower operating pressures, no need for a regenerator to make lower operating pressures useful, and no Stirling engine.
You're going to need to replace more than the aluminum and the smaller the device the less power it will generate. Also, Stirling's original engines ran at very high temperatures for his time causing regular hot cylinder failures and leading to his engine being replaced by a more conventional one.
Valdemar II
Banned
I'm with Don Lardo on this, through I don't think the device are impossible to make, it would be little more than a expensive toy, there wouldn't be anything to use it to. The problem are while it's a good and interesting idea, the problem are that a first generation Sterling engine would be inferior to a first generation stream engine. So while it have potential, it would need a rather unique situation to succeed, earlier development of generators or dynamoes could be one.
I'm thinking they could build one, what I can't work out is how they'd get the idea to build one. They aren't simple or intuitive machines and, very importantly, there's nothing like a regenerator at work in any of the other devices of the period the OP suggested. The regenerator idea is extremely critical to the entire concept, so critical that, without it, you don't have a Stirling engine.
Stirling had steam engines using condensers for various things and atmospheric engines which cooled their cylinders as working devices that could suggest the regenerator idea to him, but what devices will our 16th Century watchmaker have to suggest the idea to him?
Very true. The first commercial installation of Stirling's design was replaced by a conventional steam engine within a few years.
Household gadgets most likely. Fans, small volume pumps, gizmos like that.
Power output is going to be the hurdle there. Stirlings run at higher temperatures for a given power output, that's one reason why that first commercial installation didn't last long. The more work you want out of them, the higher the "hot side" temperature and the less likely the metallurgy of the day is up to the task. Electrical production for low powered household gadgets rather than industry would be a lower hurdle to overcome.
If I can only figure out how the regenerator idea can be developed earlier...
I think that Denis Papin's second steam engine was similar enough (not very, but there are some points) to a Stirling that he could have made the leap. Regenerator I'm less sure about, but if anyone could have done it, he could have, but only given years he didn't get.
Looking at how revolutionary Papin was for his time and how much more advanced the Stirling was than what he built, I see no way that someone two centuries before him could spontaneously develop a Stirling. Let us not forget that he didn't work in vaccum. He worked with and learned from inventors and scholars as ingenious and revolutionary as he was.
Looking at how revolutionary Papin was for his time and how much more advanced the Stirling was than what he built, I see no way that someone two centuries before him could spontaneously develop a Stirling. Let us not forget that he didn't work in vaccum. He worked with and learned from inventors and scholars as ingenious and revolutionary as he was.
Other than the fact that both use the pressure of a working fluid rather than atmospheric pressure, they have nothing in common and differ in very fundamental ways. For example, Papin's engines were open-cycle types while one of the two hallmarks of the Stirling engine is it's closed-cycle nature.
He lived into his sixties, that's pretty good for time.
Papin was more evolutionary, but I agree with the rest of that statement.
Again agreed. Stirling's work was in response to boiler explosions and other accidents. He also had a century or more of steam engine development to draw upon along with increasing condenser usage.
Stephen
Banned
Just because that is the way hot air engines were invented OTL I dont think that is the only way they could posibly be invented. There are also allot of hot air engines that dont have a regenerator just a displacer.
There are hot air engines like the one picture that operate at temperature diferences of only a few degrees true it has no use other than as a toy. But when given the idea a watchmaker would be fully capable of replicating it, and small low powered devices could act as an inspiration for building larger more powerful engines. The steam engine evolved from completely impractical and ineffiecient prototypes aswell.
Howabout this:
Mr Tik Tok the watch maker is startled from his nap by a suden bang, it seems to of come from an empty bottle he left near the fire which has poped its cork. The cork has left a bruise on the back of his head so he curses himself for not just throwing the cork in the fire. This moment stick in his mind how could a cork leave an empty bottle with such force. Evenually he come to the conclusion that hot air must expand and with a suprising amount of force when contained too. He gets a test tube from his alchemy set and observes as a stopper climbs the tube when he heats it up and falls when he cools it down. Being a mechanically minded person he ponders the idea of using this power in a machine he toys with the idea of moving the cylinder between hot and cold areas but then eperiments with moving the air in a cylinder between hot and cold ends. After some development he starts making some out of brass to sell as toys and run automatons, and a clock that can be mounted in a chimney and never need winding although the acuracy was not so great. He trys to sell a few larger engines for turning spitroasts but most people seem to find it easier to just hire a kitchen hand when you need one. But one day when one of his children is playing with one of his motors when snatching it away from the insolent child he is surpised at how one side is hot and the other is cold. After further experimentation with hand cranking his motors he buys a watermill, builds his bigest motor yet and attaches it and makes a fortune selling ice.
One day when pondering the nature of air in his machines he realises that if air is larger when it is hot it must be lighter for its volume too and tries to weigh it. He concludes that must be how the chimney works, and after playing with pillow casses decides to make a hot air balloon. After a few flights he says why not atach one of my motors to the fire pot above the basket, and with a ruder and autofan makes the worlds first airship!
But what would prompt someone to invent one without such a situation?
I'm not familiar with the absolute earliest steam engines - of the sort of any real use whatsoever - but if this is a reference to the temple toy, God have mercy on you, because Don Lardo won't.
Am the only one going
at this theory? And not in a good way?A Stirling engine isn't a "hot air" engine. A Stirling engine refers to a very specific type of heat engine which employs a working fluid in a closed cycle.
The displacer type of Stirling engine was developed after the regenerator type, after Carnot's heat engine theories were rediscovered, and after the Laws of Thermodynamics were quantified. There are many reasons why the regenerator type was invented first and one of those reasons was that the regenerator type provides a lower "developmental hurdle" for a pre-modern or early modern tinkerer/engineer constrained by to empirical methods.
Once again, it's a Stirling engine because it is a closed cycle engine and not because it uses hot air as it's working fluid.
That's the problem here: WHERE does the idea come from?
No. The earliest steam engine was developed from a rather successful device meant to "cook" bones so they could be more easily ground into meal while also drawing off any liquid fat produced during the process. If you come up with explanation why a Stirling engine can be derived from the operating principles behind that "bone cooking" device I'd very much like to read it.
How about no.
There are so many mistaken assumptions, unwitting anachronisms, and just plain face palm moments in that "story" that I scarcely know where to begin.
That story with it's many defects and suggestion about a Stirling engine driven airship, plus with your incomprehension of just what a Stirling engine is and inability to even correctly spell Stirling engine, means this thread is now at an end.
If you want to keep this discussing this idea in the manner you have been discussing it a better venue will be ASB board.
Edit: Elfwine: You are not the only one going
or even with Stephen's latest post. You were able to post your response before mine because I had to first stop laughing and then compose something that wouldn't get me kicked.
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Don Lardo said:Edit: Elfwine: You are not the only one going
The worst part - and I'm saying this half to you and half to Stephen - is that it dresses it up as something vaguely logical, while the actual stuff is so fundamentally bizarre to be impossible.
You might get someone discovering how to make a Stirling* engine earlier. You might even get it from a watchmaker. But this is not how it could be developed.
At most, the likely result of hot air = expands = wonder what I can do with this will involve something like an air gun. That's the logical development (or intended development).
That's an apt observation. While the progression he presented connects the individual steps in a logical manner, the individual steps themselves are completely bizarre.
It's like many of the passages in Carrol's "Alice's Adventures in Wonderland": The components making up those passages are nonsense, as are the situations being described, but there is an internal logic within the nonsense.
I'm afraid that upon reviewing a diagram of Papin's second engine, My former understanding of its operation was in error. I had thought that the steam part was a closed system, operating a piston that pushed water out to do I don't know what. But now I see the valves that are doubtlessly there to let out vapour and let in more water and whatever else they do. I really wish I could find a good book on that. Congratulations, you've mortally wounded one of my favourite AH ideas.
When people die in unaccustomed poverty, I tend to think they could have lived a bit longer. But, yes, not a bad age, even for today. Somebody's got to balance the 100+ year olds to make the average life expectancy 78 years.
Bad choice of words on my part. I meant that he was far beyond the technology of the times, though manifestly influenced by contemporaries and predecessors.
Interesting...
...When I read the OP title I thought it was a reference to a printing press/printing engine used to produce banknotes. But it turned out just to be more about hot air.
...When I read the OP title I thought it was a reference to a printing press/printing engine used to produce banknotes. But it turned out just to be more about hot air.
If that were only true.
I'm quite certain some technological illiterate will be posting a thread about Stirling engines, Tesla's death rays, or the aeropile any week now.Anyway, I didn't wound your idea, the actual facts did.
While he was not beyond the technology of the times, he did have some influence.