Originally posted by cylon555
Which engine is the most efficient you would want an engine
that can get airborn on the least amont of fuel
so you have plunty for your mission and to land.
A very good question but one we cannot answer very well because manufacturers don't have all the data.
The key figure here is called Specific Fuel Consumption (SFC) and is given as a weight of fuel per equivilent weight of thrust, i.e. an SFC of 1.67
means that it burns 1.67lb of fuel for every lb of thrust, per hour. These figures are normally (if ever) published for the SFC at maximum power which
whilst a good indicator of engine efficiency, isn't the whole picture.
The Eurojet EJ-200
is sold as having "low fuel consumption". Although the official docs I've seen don't quote figures, the reputation is
that it is extremely efficient. The health warning here is that the EJ-200 is marketed as a factor in the Eurofighter's supercruise capability so it
actually has a quite high thrust without afterburner and because it is so light, particularly wet (figures we normally have are for a dry engine)
it's thrust to weight ratio is the key factor.
One generally good site says:
" At its maximum dry thrust of 60kN (or 13,500lbf) the EJ200's SFC is in the order of 23g/kN.s. With reheat the engine delivers around 90-100kN (or
20,250-22,500lbf) of thrust with an SFC of some 49g/kN.s. [Comment: - note figures given per second not per hour] Compared to other engines
these figures may actually seem relatively high, however such data must be used with caution and evaluated with all other performance data to be of
any use. With reheat the engine weighs just 2286lb giving a Thrust to Weight Ratio of around 9:1."
From that we can run with SFC figures of 1.76 with full afterburner (?) and 0.82 at full military power (i.e. not afterburning).
The Snecma M88-2
has a SFC of 1.7 with full afterburner and 0.8 at full military power.
The General Electric F414
doesn't have a published figure for specific fuel consumption but assuming it is as good if not better than the
from which it was developed (used on Gripen, hornet etc), then it is at least 1.74 with full afterburner and 0.81 at full military
The Klimov RD-33
has a SFC of 2.05 with full afterbrner and 0.77 at military thrust.
The biggest engine, the General Electric F110-100
has a published specific fuel consumption of 2.06 at maximum thrust.
So, my guess of which are are most efficient, with full afterburner:
Joint 1st. General Electric F414 & Snecma M88-2
3. Eurojet EJ-200
4. Klimov RD-33
5. General Electric F110-100
GENERAL CORRECTION ON MY PREVIOUS POST: The diagram shows the F414 engines as P&W when it is actually made by GE.
[edit on 9-6-2006 by planeman]