Why is hydrogen not used as fuel for fighters? I understand that hydrogen engines are not yet developed but why is there no research going on in that file. Can't hydrogen be used in specially designed afterburners? After all, is has like 3 times the energy density of aviation fuel.

  • $\begingroup$ One part of the reason: while hydrogen has a high energy density, is has a much lower physical density, meaning that a tank of hydrogen with as much energy as a tank of jet fuel will be much larger. This makes for a heavier tank shell, and takes up more space inside the plane, displacing weapons and computers or forcing a bigger airframe. $\endgroup$ Commented Nov 5, 2020 at 7:34
  • $\begingroup$ aviation.stackexchange.com/questions/18809/… $\endgroup$
    – BowlOfRed
    Commented Nov 5, 2020 at 8:06
  • $\begingroup$ perhaps not now but in the future is there a possibility that the turbines of the jet engine can be rotated by electric motor and hydrogen can be used to heat the air inside the turbine to increase pressure? $\endgroup$ Commented Nov 5, 2020 at 12:10
  • $\begingroup$ Not sure about the electric motor - the batteries powering it might be too heavy. You could use a generator make electricity for the motor, but then you'd need something to spin the generator. $\endgroup$ Commented Nov 6, 2020 at 2:21


Browse other questions tagged .