18

RP-1 isn't cryogenic actually. The subcooling for RP-1 is only to cool it to slightly below the freezing point of water, 20 F. At that temperature, no extreme cooling is required. The temperature difference is quite small compared to the larger LOX temperature difference, and the fuel is only there for 35 minutes. There likely isn't a need to cool the RP-1 ...


17

The way you ignite a rocket engine depends a lot on the fuel/oxidiser combination. Some combinations, like Liquid Hydrogen/Liquid Oxygen (HydroLox) ignite very easily and are ignited using a glorified spark plug (this is the case of the RL10, used on the Centaur Upper Stage). The RP1 (Kerosene)/Liquid Oxygen mixture is harder to ignite, and requires more ...


12

Each technology has their own strengths and difficulties. It's really difficult to explain this without going in to a great detail about how rocket engines work, but let me try and give a brief overview. There are a number of different ways you can power a rocket engine. In general, for the same fuel and engine size, the higher the chamber pressure, the ...


7

According to this nasaspaceflight.com forum post, the dynamic viscosity of Falcon 9 chilled RP-1 is about 3.3 cP. The table here lists the viscosities of some maybe-not-so-everyday fluids; Falcon fuel is kept twice as viscous as ordinary kerosene at room temperature (1.64 cP), comparable to milk or blood. Water at room temperature is 0.89 cP. I tried to ...


6

RP-1 Was Adopted By The Military Because It's Storable, Temperature-Insensitive, and Similar To Jet Fuel According to Clarks' Ignition, the adoption of RP-1 rocket kerosene as the standard fuel for hydrocarbon rockets was very much a result of military concerns, including logistics, but it was a bit more complicated than you described. To summarize Clark: ...


4

Methane/LOX specific impulse is only slightly better than kerosene/LOX and it's about 25% less dense. In this case I think stretching the first stage would be more likely than fattening it; furthermore it might be possible to use a common-bulkhead tank instead of the separate tanks of the S-IC, (the temperature differential between liquid methane and liquid ...


2

I don't know of any RP-1/kerosene fueled engines that used two fluids for film cooling. The only instance of film cooling was of the gas generator exhaust fluid being fed into the nozzle to insulate it from the hot combustion products streaming out of the chamber. This btw was responsible for the F-1 exhaust gases always looking brighter in the center of the ...


2

I did find on Astronautix several examples of pressure fed kerosene-LOX engines, some of them built, others "notional": AABS Liberty KSR-3 P4-1 RS-36 PF RP-1 Sea Dragon-1 Microcosm 22N As well as some gas generator hypergolics, mostly Russian vernier thrusters: 8D423/11D423 (UR-100) RD-0207 (UR-200 vernier) RD-0230/RD-0257 (SS-18 vernier) RD-0236/RD-0251 (...


1

A spark won't do anything until the engines are already pumping fuel/oxygen Rocket engines use a LOT of fuel/oxygen. Each Merlin 1D engine has a 12,000 horsepower propellant pump (~100,000 HP total, just in the pumps). But the pump itself is like a jet engine, driven by the expanding gasses - so you need fuel+oxidizer already in place to generate the gasses ...


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