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Given the heat from combustion and increased temperature, would the LOx still be in liquid form after emanating from the injector? Or will it instantly transform into gas?

Are injectors cooled using the flow of LOx or is there a separate cooling system for the injector? If cooled using LOx, then this additional heating would make the LOx's temperature to rise even further. This might cause the phase transformation even before entering the combustion chamber.

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  • $\begingroup$ There will be no instantly evaporation of liquid oxygen. This will take some time, but a very short one. I guess some milliseconds or even microseconds. But it is difficult to avoid oxidation of the injector itself. $\endgroup$ – Uwe Feb 6 '18 at 10:05
  • $\begingroup$ Is the phase diagram or table for Oxygen available? I am able to find diagram for very high pressure range(it's 1GPa after 0 along x-axis). $\endgroup$ – karthikeyan Feb 6 '18 at 13:10
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    $\begingroup$ I've seen videos of fuel mixture diffusing and igniting in a car engine "combustion chamber", wow wouldn't it be great if there was a way to do this with even a small rocket engine? Diamond or sapphire window might work for a short time? $\endgroup$ – uhoh Feb 6 '18 at 15:39
  • $\begingroup$ A diamond window should not be exposed to a high concentration of oxygen. Diamond's ignition point is 720–800 °C in oxygen and 850–1000 °C in air. Sapphire does not burn and its melting point is at 2030 to 2050 °C. $\endgroup$ – Uwe Feb 6 '18 at 16:28
  • $\begingroup$ The LOX (and fuel) are sprayed as liquid through the injector plate, as impinging streams (typ LOX on LOX and fuel on fuel) to break into small droplets for mixing. Good info at:heroicrelics.org/info/f-1/f-1-injector.html $\endgroup$ – amI Feb 6 '18 at 21:59

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