[AR] Re: RP-1 versus ethanol for a student rocket?

  • From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
  • To: Arocket List <arocket@xxxxxxxxxxxxx>
  • Date: Wed, 14 Oct 2020 22:39:24 -0400 (EDT)

On Wed, 14 Oct 2020, ken mason wrote:

      Trick question. What the Brits reach temperature wise with H2O2
      in their regenerative cooled designs?

Was the fuel or oxidizer the coolant? O/F vol ~4/1.

Mostly oxidizer-cooled. Peroxide has a much higher specific heat than kerosene, and it's dense, and you need a lot of it for optimal mixture ratio, so overall it makes a great coolant. (Does mean that you can't use copper for the chamber, though.)

The nozzle extensions on the Black Arrow second-stage engines were fuel-cooled, so they could be left off -- to test the full second-stage engine assembly in sea-level air -- without altering the chamber cooling.

Henry

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