From: Chuck Kuecker (ckuecker@ckent.org)
Date: Fri Feb 28 2003 - 05:38:16 MST
Just to correct a misunderstanding - and I bet Mike Lorrey will chime in,
in support here.
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. A
better parallel would be a turbocharger, which uses waste heat to overcome
some flow losses in the engine.
Running a laser on exhaust gases may well be a cheap way to get laser
output in places where a conventional laser is difficult to use. I wonder
just how much energy is put back into the system in the "reheating" after
all the useful energy in the exhaust has been lost. This would appear to be
where any laser output would come from - the engine is simply providing the
laser medium, not the energy in the output. In any case, the Carnot cycle
is in no danger of being outdone once the gas has left the engine.
I would hope if any lab testing is done, that very careful measurements of
heat input during the "reheat" stage versus total engine and laser output,
combined, are made. Otherwise, this could easily be another "cold fusion".
Chuck Kuecker
At 10:56 02/28/2003 +0100, you wrote:
>OK, here is a version of the message with some useful physical information
>rather than the hype of the home university:
>
>(if he really goes beyond the Carnot cycle, then there is real news - but
>breaking thermodynamics is hard, since you have to break probability
>theory)
>
>The quantum afterburner
> 4 February 2002
>http://physicsweb.org/article/news/6/2/2
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