Zephyr Net

hey i need to use this information for fighters anthology:

Mirage 5 SNECMA Atar Engine:

# Specific fuel consumption:

* 103 kg/(kN·h) or (1.01 lb/(lbf·h)) military power
* 207 kg/(kN·h) or (2.03 lb/(lbf·h)) with afterburner

what will this be in terms of lbs/s ??

thanks

_________________

Belly full of HELL

Multiply your lbf.h x thrust divide by 60 x number of engines.

_________________
Fighting for justice with brains of steel

Let your anger be like the monkey which hides inside the piniata.

thanks for the reply kap but im still lost a bit. so if im to calculate fuel consumption in lb/s at full thrust:

now 2.03 x 13,240 x 1 hour = 26877.2 lb of fuel needed to provide 13k of thrust in 1 hour??? meaning 447lb of fuel / second ???? O.o

is this correct?

_________________

Belly full of HELL

Divide by 3600 rather than 60.

So this engine works out to 7.466 lbs burned per second at afterburner.

Assuming this "Mirage aircraft" has 9,000 lbs of fuel, it can run maximum afterburner for 20 minutes before emptying a full fuel tank. Sounds reasonable?

oh ya i just got that. thanks zephyr. and i dont think its reasonable lol.

GE J79
11,905(lbf) x 0.85 lb/(h·lbf) / 3600 = 2.81 lb/s of fuel
17,835 lbf x 1.965 lb/(h.bf) / 3600 = 9.73

GE F110
17,155 (lbf) x 0.73 lb/(h·lbf) / 3600 = 3.47
28,000 (lbf) x 2.06 lb/(h.lbf) /3600 = 16.02

RD-33
11,230 lbf x 0.77 lb/(h.lbf) / 3600 = 2.40
18,285 lbf x 2.05 lb/(h.lbf) / 3600 = 10.41

SNECMA Atar
9,440 lbf x 1.01 lb/(h.lbf) / 3600 = 2.64
13,240 lbf x 2.03 lb/(h.lbf) /3600 = 7.46

GE J85 used F-5E
5000 x 2.13 / 3600 = 2.95 lb /s

clearly the Atar engine for the Mirage 5 is the worst in terms of efficieny and power. but then again they are very light aircraft, still doesnt explain the inefficiency in the engines. The GE F110 seems very very efficient on dry thrust. but it has the disadvantage of size. The GE j85 for the f-5 seems pretty decent.

_________________

Belly full of HELL

You forgot to factor in drag, which overcoming consumes a large portion of the fuel at burner...

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Drag has nothing to do with fuel burn rate, only the performance you get out of it.

The ATAR is a very old engine more comparable to the J79 than the other engines listed. Just generally speaking, the larger the engine, the more efficient it is.

_________________
Fighting for justice with brains of steel

Let your anger be like the monkey which hides inside the piniata.

I wasnt responding to the fuel rates, which is why I deleted them from the quote. I was responding to his not thinking the performance of the mirage aircraft was reasonable, which it isnt, until one factors in its drag...

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"FAF Shape Meister"
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TSH Member/Developer
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FA Futures/FA-2 is Still Being Worked On and Will Be Released...

Here is a website that list jet engines with their thrust values and specific fuel consumption.

[url]http://www.jet-engine.net/miltfspec.html[/url]

(I know this is an old thread, but is a recent project for me.)

Speaking of list, does anyone have a list for man-hours maintenance for aircraft?

Thanks for posting that raptor. I'm working on a lib and was looking for accurate engine outputs. (especially for the F-14A vs. the F-14B and D)