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What are the materials used in the Rocketdyne F-1 engine's turbopump design and what was the pressure rise?

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  • $\begingroup$ The pressure at turbopump output should be somewhat higher than the chamber pressure of 70 bar. $\endgroup$ – Uwe Jul 14 '18 at 11:59
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    $\begingroup$ Check this question too - space.stackexchange.com/questions/25095/… $\endgroup$ – karthikeyan Aug 4 '18 at 14:31
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The F-1's LOX turbopump had an inlet pressure of 65 psi and an outlet pressure of 1600 psi.

Materials:

Inlets, volutes, and impellers, aluminum alloy casting. Turbine wheels and manifold assemblies, nickel alloy.

References

Materials

Pressures (Table II)

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  • $\begingroup$ The outlet pressure of 1600 psi is much higher than the chamber pressure of 1015 psi. Where is the main pressure drop, at the injector only? The LOX tank of the Saturn V was pressurized to 65 psi? Pretty high for such a large tank. $\endgroup$ – Uwe Jul 14 '18 at 12:47
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    $\begingroup$ I would be surprised if the inlet pressure was constant during a flight. The head pressure would change due to the dropping height of LOX in the tank and the changing acceleration. $\endgroup$ – Organic Marble Jul 14 '18 at 12:53
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    $\begingroup$ I searched for some numbers, the LOX tank of the first stage of Saturn V was 19.5 m high, it was pressurized to 1.8 bar before start and to 1.2 to 1.6 bar during flight 1. The lower RP-1 tank had a length of 13.1 m. The density of LOX is 1.141 g/cm^3. The pressure caused by 19.5 + 13.1 m of LOX is 3.77 bar at 1 g. 1.8 bar at top of tank plus 3.77 liquid pressure are 5.56 bar. The turbopump inlet pressure of 65 psi is 4.48 bar. A halve full LOX tank at 2 g would result in a inlet pressure of 6.88 bar. $\endgroup$ – Uwe Jul 14 '18 at 14:11
  • $\begingroup$ Good numbers! I remembered the SSME inlet pressures varied a lot for the same reason, but did not have details on the F-1. $\endgroup$ – Organic Marble Jul 14 '18 at 14:14
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    $\begingroup$ There are plots in the post-launch mission reports showing LOX pump inlet pressure at 81.9 psia (5.65 bar) at ignition, with an acceptable range from about 77 to 164 (!) psia. LOX ullage pressure goes from about 27 psia at ignition to about 19 at 1st stage cutoff. (Specifics from Apollo 12 but I assume they're all similar). No plot of the inlet pressure over the whole burn, though. I'm guessing the 65 psi is the minimum rated inlet pressure for the engine, below which there's cavitation risk? $\endgroup$ – Russell Borogove Jul 14 '18 at 14:27

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