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What is the combustion efficiency of liquid fuel rockets?

  1. May 9, 2018 #1
    How efficiently is the fuel burned in a typical liquid fuel rocket engine? I've heard numbers ranging from 95% to below 50%.
  2. jcsd
  3. May 9, 2018 #2


    Staff: Mentor

    This is not a direct answer to your question. However, it indicates that combustion efficiency is not the right question.

  4. May 10, 2018 #3


    User Avatar

    As anorlunda indicates, combustion efficiency really isn't the correct figure of merit. Instead, rocket engineers look at things like impulse density (how much momentum change can you get from a given volume of fuel), specific impulse (how much momentum change can you get from a given mass of fuel), and thrust per engine diameter (different fuels will require different sizes of engines to produce the same thrust).
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