From: spike66 (spike66@attbi.com)
Date: Fri Feb 28 2003 - 11:21:59 MST
Chuck Kuecker wrote:
>
> An afterburner, on a jet engine, does not "extract" energy from the
> exhaust - it dumps a large amount of fuel into the exhaust, providing a
> rocket-like thrust augmentation. Afterburners suck huge amounts of fuel,
> rather inefficently, which is why they are used only when absolutely
> necessary...
The term "rather inefficiently" is an understatement.
If one looks at the curve for additional thrust vs
additional fuel use, it is enormously inefficient. It
amazes me that it would work at all: the afterburner
tosses unburned fuel into the exhaust stream.
Perhaps what they really had in mind is if a plane is going
into combat it needs to lighten its fuel load somehow.
Burning it inefficiently is no worse than just throwing
it overboard unburned I suppose. An F-4 jockey told
me the afterburners could run for a little less than
5 minutes full tanks to empty.
spike
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