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For a rocket having 95% combustion efficiency, total chemical power of 17MW, a mass flow rate of propellants of 15 kg/s, and effective jet exhaust velocity of 1443 m/s, find the internal efficiency of rocket propulsion.

For a rocket having 95% combustion efficiency, total chemical power of 17MW, a mass flow rate of propellants of 15 kg/s, and effective jet exhaust velocity of 1443 m/s, find the internal efficiency of rocket propulsion. Correct Answer 97%

Internal efficiency of rocket propulsion is the ratio of kinetic power in the jet to the available chemical power. It is an indicator of how much the system is capable of converting input energy into useful kinetic energy. Pav chem = ηcomb x Ptot chem = 0.95 x 17 x 106 W ηint = Pkinetic / Pav chem = 1/2μe2 / Pchem = 0.5 x 15 x 14432 / (0.95 x 17 x 106) ≅ 0.966.

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