The title says it all, does the compressor use electricity? if so, how does it generate this electricity? The main power source can't be from the compressor itself as it would lose more power than it would gain.

Not a duplicate of: How much power is drawn by a turbofan to power its own compressor?

  • $\begingroup$ This question reveals insufficient prior research. Try searching for diagrams and illustrations of turbojet engine construction. $\endgroup$ Apr 29, 2018 at 23:25
  • $\begingroup$ No. They don't . There is a turbine driving it. $\endgroup$ Apr 29, 2018 at 23:31
  • $\begingroup$ You seem to be confusing power with electricity. $\endgroup$ Apr 29, 2018 at 23:33
  • $\begingroup$ @A.I.Breveleri I have done my research, all I've found are diagrams of how the air flows, I needed to know what makes the fan actually turn. $\endgroup$ Apr 30, 2018 at 2:59
  • $\begingroup$ Surely you must have noticed that the compressor and the turbine are on the same shaft. - Although, I must admit, that shaft is not explicitly labeled in any diagram I've seen. - It runs right through the middle of the combustion chamber section of the engine. $\endgroup$ Apr 30, 2018 at 3:44

1 Answer 1


a gas turbine engine does not use electricity to spin its compressor stage. the compressor discs are driven by a geared shaft which is rotated by the exhaust turbine.

the thermodynamic cycle which forms the basis of operation of a gas turbine engine is called the brayton cycle. an analysis of the brayton cycle shows that the majority of its (gross) power output is used to operate the compressor stage. The remainder represents the useful (thrust) output of the engine.

  • $\begingroup$ If that's so, a compressor, like the name states, compresses air into the combustion chamber which requires a decent amount of torque, so are you saying that the thrust generates the compression as well? $\endgroup$ Apr 30, 2018 at 1:50
  • $\begingroup$ @talkingmango, no: the combustion of fuel in the engine provides the expansion of the airflow through the engine; when this airflow goes through the exhaust turbine, it furnishes the torque that is fed to the inlet fan (compressor stage). what power remains after powering the compressor is used for thrust. $\endgroup$ Apr 30, 2018 at 5:15

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