I would like to know if a fuelless engine is possible in reality. I think you've heard of the Chinese making one.

Can there be an engine that doesn't require any fuel?

The idea is to make human-built mechanisms work without fuel of any kind. No oil, no plasma or wind, or solar power, or pressure, or anything of the kind.

I want a type of engine that can work on its own and provide power to mechanisms.

It's hard for me to explain. But the idea is to make a device with just one button start/stop. The bigger the device the more power it provides. But you don't need anything to make it produce power. Think of it as a kind of "magical power generator" but without magic or an everlasting battery. And it won't heat up or cool down.

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    $\begingroup$ Yes, electric ones. Can you clarify what world you are building? And what your want to use such engines for? Because I guess you already know electric motor can be built. $\endgroup$ – Mołot Oct 24 '17 at 7:03
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    $\begingroup$ I like the edit. Please define fuel. It's not intuitive to say wind or pressure is fuel. It sounds as if you kind of want to ask about perpetual motion but do not know the right words. You might also be asking about some energy sources available anywhere like zero point esoteric stuff, but in any case you need to give us a good definition of what you think is fuel and what the Chinese are apparently building $\endgroup$ – Raditz_35 Oct 24 '17 at 7:14
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    $\begingroup$ "I want a type of engine that can work on its own and provide power to mechanisms." Yeah, you and everyone else... :) $\endgroup$ – Xenocacia Oct 24 '17 at 7:18
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    $\begingroup$ What exactly do you want to know? If you assume star trek style technology where they alter how gravity works and travel in time one can approximate this. If you want blue prints how to build one - forget it. If you want to write some sort of tech fiction, I would advice reading some books about thermodynamics first $\endgroup$ – Raditz_35 Oct 24 '17 at 7:26
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    $\begingroup$ I'm voting to close this question as off-topic because this question seems more fitting to any of the Engineering Stacks $\endgroup$ – dot_Sp0T Oct 24 '17 at 8:26

I think you are making a bit of confusion.

What the Chinese plan to test in space is a reactionless drive, which is fantascientific enough as it (apparently) puts an end to Newton's Third Law.

Such an engine (if and when operable) wouldn't need "fuel" in the sense it does do without the reaction mass any rocket needs to eject in order to accelerate in the opposite direction.

Such an engine,though, still need energy, from some source.

This is not a way to obtain energy without "fuel" (in the meaning "something you "burn" to get energy).

What you are asking for (it seems) is "moto perpetuo" which is not what I read about and AFAIK is still strictly "not possible".

Actually EM-drive seems just as "impossible" to me, so you may have some hope... if it turns out to be true.

  • $\begingroup$ Some of theproposed theoretical frameworks for how such a reactionless drive might not violate conservation of momentum make sense in a “it’s quantum” kind of way, but they’re crazy complicated and rely on a few crucial assumptions. $\endgroup$ – Joe Bloggs Oct 24 '17 at 9:05

Thermodynamic tells us that in order to have useful energy out of a system, we need to supply some more energy in that system. Fuel is what is used to supply this energy.

Fuel-less engine, intended as an engine which throws out energy without taking energy from something else, is a non sense.

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    $\begingroup$ Steam engine heated using parabolic mirror instead of coal works. Unless you count Sun's fusion as fuel, your answer is nonsense. And if you do, then sailboats use fuel, too. $\endgroup$ – Mołot Oct 24 '17 at 7:18
  • $\begingroup$ @Mołot, somebody wrote an entire poem about a sailboat stuck in a windless ocean.. plus the OP also counts wind $\endgroup$ – L.Dutch - Reinstate Monica Oct 24 '17 at 8:32

You could run a modified internal combustion engine off of liquid nitrogen using heat extracted from the environment to boil the nitrogen and provide the necessary gas pressure. The nitrogen would be more a working medium than fuel. Although I suspect it would not meet your requirements, it is probably as close as you are going to get. Ultimately you cannot get something for nothing and there’s no such thing as a perpetual motion machine.


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