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I have been reading about combustion chambers and noticed they seem to just be an empty space with the fuel and oxidizer coming in one end and the nozzle at the other end.

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If the shape below were made out of metal that just had fuel and oxidizer going in the top through tubes, and the bottom was flared out like in the picture to make a nozzle, would that work?

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  • $\begingroup$ I posted a meta question about this one $\endgroup$
    – user10509
    Commented May 21, 2019 at 17:20
  • $\begingroup$ Cooling of the combustion chamber walls might be essential. If cooling fails, the chamber will be destroyed in a very short time. $\endgroup$
    – Uwe
    Commented May 21, 2019 at 21:00
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    $\begingroup$ It's not just an empty space, it's a partially enclosed space, and when you've got compressible fluids moving through that space at high velocities and high pressures, the geometry of the enclosure could have a profound effect on how the fluids move, pressure gradients, standing wave patterns, etc. $\endgroup$
    – Solomon Slow
    Commented May 22, 2019 at 0:23

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'tubes' aren't enough. You want an injector, in order to atomize the fuel and oxidizer and mix them. A simple one is the pintle injector, which has concentric openings for the fuel and oxidizer.

Fuel being injected:

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and oxidizer:

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Other injectors have lots of openings alternating fuel and oxidizer, like the F-1 engine used in the Saturn V:

enter image description here

You also need a way to ignite the mixture.

The combustion chamber is just an open space with a constricted opening at one end. The chamber walls have to be cooled (this is usually done by having a double-walled setup and running the fuel between those walls), or they'll get hot enough to melt.

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  • $\begingroup$ Thank you very much for your answer. I figured the injection part would need to be special made. The rest of it (the chamber being pretty much just open space) is correct though? $\endgroup$
    – Putvi
    Commented May 21, 2019 at 18:49
  • $\begingroup$ Sorry to bother you again, but as for the igniting it, can it just be lit with a flame or lighter? $\endgroup$
    – Putvi
    Commented May 21, 2019 at 19:37
  • $\begingroup$ The Soyuz is still ignited essentially with a match. popularmechanics.com/space/rockets/a19966/… $\endgroup$
    – Greg
    Commented May 21, 2019 at 20:10

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