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TIL about the simplest combustion engine (teapot engine)
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gandalf_der_13te
feddit.org

gandalf_der_13te@feddit.org
Joined: 2026-08-01
Posted: · edited   Subject: TIL about the simplest combustion engine (teapot engine) Quote

idk whether it's actually called that way. i was researching what is the simplest possible combustion engine, i.e. something that turns heat energy into mechanical energy. i stumbled across the newcomen engine which is said to be even simpler than the watt steam engine. however, even then, there were even simpler historical precedents. and one of them is depicted in the graphic that i made above. it's also described in the newcomen engine wikipedia article (section "Precursors").

next i'm gonna calculate the efficiency. it's somewhere around 5% actually, assuming operational pressure of 2 bar, which means 1 kWh of heat energy turns into 0.05 kWh of mechanical work. not thaat bad. i did a rough calculation already, now i'm gonna refine the formula.

27   Original
infeeeee
lemmy.zip
infeeeee@lemmy.zip
Joined: 2025-06-05
#2 Posted: · edited   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

  1. Wrong community
  2. Ai slop image
  3. If you are looking for the most basic, earliest, first tried steam engines, you are several thousand years off: https://en.wikipedia.org/wiki/Aeolipile
6
gandalf_der_13te
feddit.org

gandalf_der_13te@feddit.org
Joined: 2026-08-01
#3 Posted: · edited   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

Wrong community Ai slop image If you are looking for the most basic, earliest, first tried steam engines, you are several thousand years off: https://en.wikipedia.org/wiki/Aeolipile
  1. nope
  2. sry
  3. thanks but mine is simpler as it doesn't rely so much on moving parts. the aeolipile inherently needs to connect two parts that rotate against each other, while theoretically my engine can be operated without a turbine to create thrust directly through the recoil principle to drive a vehicle forward.
-5
whaleross
lemmy.world

whaleross@lemmy.world
Joined: 2023-07-02
#4 Posted:   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

Wrong community Ai slop image If you are looking for the most basic, earliest, first tried steam engines, you are several thousand years off: https://en.wikipedia.org/wiki/Aeolipile
  1. No it's not.
  2. Oh fuck off
  3. You could have just told OP about this politely and it was more a curiosity than an engine. The first known practical use was the kebab spinning engine several thousand years later.

OP, you probably already read https://en.wikipedia.org/wiki/History_of_the_steam_engine and https://en.wikipedia.org/wiki/Taqi_ad-Din_Muhammad_ibn_Ma%27ruf

6
Thorry
feddit.org
Thorry@feddit.org
Joined: 2025-08-30
#5 Posted:   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

Never slop, why would you use an AI image here? There weren't enough images of teapots on the internet?

40
tangeli
piefed.social
tangeli@piefed.social
Joined: 2024-11-21
#6 Posted:   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

There are engines (devices that turn heat into mechanical energy) with no moving parts. That seems simpler to me.

pop pop boat

pulse jet engines

9
gandalf_der_13te
feddit.org

gandalf_der_13te@feddit.org
Joined: 2026-08-01
#7 Posted:   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

Never slop, why would you use an AI image here? There weren't enough images of teapots on the internet?

didn't check, picked the first i saw and liked

3
printf("%s", name);
piefed.blahaj.zone

akunohana@piefed.blahaj.zone
Joined: 2026-03-30
#8 Posted:   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

Cool! I know the complexity of its design and operation are off the charts, but I recently learned how nuclear power plants work - or, at least the ones with boiling water reactors - and it's AMAZING. It's principally the same, except "fission and radioactive decay heats water" instead of "fire heats water".

1
deHaga
feddit.uk
deHaga@feddit.uk
Joined: 2025-11-30
#9 Posted:   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

A teapot is what you pour hot water from a kettle into to make tea...

6
theOneTrueSpoon
feddit.uk

theOneTrueSpoon@feddit.uk
Joined: 2023-08-02
#10 Posted:   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

There are engines (devices that turn heat into mechanical energy) with no moving parts. That seems simpler to me. pop pop boat pulse jet engines

I'm no expert, but I feel like a teapot is probably simpler than a pulse jet

5
tangeli
piefed.social
tangeli@piefed.social
Joined: 2024-11-21
#11 Posted:   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

I'm no expert, but I feel like a teapot is probably simpler than a pulse jet

The teapot is but the turbine, not so much.

3
gandalf_der_13te
feddit.org

gandalf_der_13te@feddit.org
Joined: 2026-08-01
#12 Posted:   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

A teapot is what you pour hot water from a kettle into to make tea...

okay then i meant a kettle

4
infeeeee
lemmy.zip
infeeeee@lemmy.zip
Joined: 2025-06-05
#13 Posted: · edited   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

No it's not. Oh fuck off You could have just told OP about this politely and it was more a curiosity than an engine. The first known practical use was the kebab spinning engine several thousand years later. OP, you probably already read https://en.wikipedia.org/wiki/History_of_the_steam_engine and https://en.wikipedia.org/wiki/Taqi_ad-Din_Muhammad_ibn_Ma%27ruf
  1. OP edited the title after my comment, the "TIL" and the first few words were added later.
  2. For such a generic image they could just use some stock photo or something. I'm not fully anti ai, I know there are some actual reasonable usecases, but this is just slop and laziness. For example here are 1000s royalty free images of boiling kettles: https://pixabay.com/images/search/boiling kettle/
  3. English is not my first language, I didn't intended to have an impolite tone, in my head it sounded neutral
2
infeeeee
lemmy.zip
infeeeee@lemmy.zip
Joined: 2025-06-05
#14 Posted: · edited   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

nope sry thanks but mine is simpler as it doesn't rely so much on moving parts. the aeolipile inherently needs to connect two parts that rotate against each other, while theoretically my engine can be operated without a turbine to create thrust directly through the recoil principle to drive a vehicle forward.

You drew a turbine on the top, how it's simpler. If you just boil the water you can't use its power, you need some mechanism to convert it to mechanical force.

Interestingly airplane engines had a similar evolution. Early airplanes, before WW1 had rotary engines, where the full engine rotated with the propeller, similar to the Aeolipile. It was later developed to radial engine, where there is a drivetrain between the propeller and the engine.

2
gandalf_der_13te
feddit.org

gandalf_der_13te@feddit.org
Joined: 2026-08-01
#15 Posted:   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

You drew a turbine on the top, how it's simpler. If you just boil the water you can't use its power, you need some mechanism to convert it to mechanical force. Interestingly airplane engines had a similar evolution. Early airplanes, before WW1 had rotary engines, where the full engine rotated with the propeller, similar to the Aeolipile. It was later developed to radial engine, where there is a...

technically one doesn't even need a turbine to make the power useful. you could just use it like a rocket engine to exhaust backwards, to propel yourself forward through recoil.

1
f314
lemmy.world
f314@lemmy.world
Joined: 2023-07-15
#16 Posted:   Subject: Re: TIL about the simplest combustion engine (teapot engine) Quote Reply

Cool! I know the complexity of its design and operation are off the charts, but I recently learned how nuclear power plants work - or, at least the ones with boiling water reactors - and it's AMAZING. It's principally the same, except "fission and radioactive decay heats water" instead of "fire heats water".

All of them spin turbines! Some just heat other stuff than water, and then transfer that heat to water to spin the turbine.

I guess one exeption would be a radioisotope thermoelectric generator, but I don’t really think those count as power plants…

2
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