> From: [email removed] (nosnhoJ enaD)
> Subject: MHD Turbines...
> Okay, somebody more in the know than I needs to explain this to me:
I don't know exactly but I suspect that it works this way:
The MHD turbine is a setup that extracts electrical energy directly out of
(hot) gas rushing through it, thereby reducing its speed (and lowering the
temperature possibly).
The total efficiency of it is higher than for a gas turbine, but the
gas will not have speed zero when it exits so this is where the thrust
comes from.
If it is anything like a better version of a gas turbine it can drink
almost anything, from hydrogen to alcohol to gasoline to lamp oil to
coal dust in water slurry and so on.
> This is dumb, 'cause it won't fly in a vacuum.
Correct, it will only fly in atmospheres 4-9, (2-9 with an intake compressor
like the one on the GUESS air/raft) and there might be trouble with certain
taints too.
The only thing except fusion, solar power and batteries that will be usable
in vacuum is fuel cells, and they need nine times the listed (MegaT) fuel
to account for oxygen as well as hydrogen.
> And really, what's the use
> of a grav vehicle that can't be used in a vacuum (or any non-compatible
> atmosphere, really).
There is the problem of thrust nowadays. Grav won't give thrust, and various
fan arrangements (that are much better than reaction mass propulsion in
atmospheres) are unusable in vacuum. Reaction mass on the other hand increases
the fuel consumption pretty badly but allows higher speeds.
The best thing for vacuum is a small craft with G-Hours etc.
(This is taken from 'Mad Geos TNE Conversions' and some reverse engineering
of my own)
> Dane
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