Thrust-specific fuel consumption: Difference between revisions

I included some more comments on the "energy content per unit mass of the fuel." Especially for rocket engines when operating at high mission velocity, there is significant energy in the form of kinetic energy. Without including this, the efficiency would appear to be greater than 100%.
(→‎Typical values of SFC for thrust engines: The higher heating value is used.)
(I included some more comments on the "energy content per unit mass of the fuel." Especially for rocket engines when operating at high mission velocity, there is significant energy in the form of kinetic energy. Without including this, the efficiency would appear to be greater than 100%.)
 
The following table gives the efficiency for several engines when running at 80% throttle, which is approximately what is used in cruising, giving a minimum SFC. The efficiency is the amount of power propelling the plane divided by the rate of [[energy consumption]]. Since the power equals thrust times speed, the efficiency is given by
:<math>\eta=V/(SFC\times h)</math>
where V is speed and h is the energy content per unit mass of fuel (the [[higher heating value]] is used here, and at higher speeds the kinetic energy of the fuel or propellant becomes substantial and must be included).
 
{| class="wikitable sortable"
353

edits