Re: Random Thoughts

T L Hayes writes:
> ....  Burning unrefined fuel means injecting hydrogen
> compounds (such as water or methane) into the reaction chamber and letting
> the ultra-high temperatures break down the molecule and fuse the hydrogen.
> The problem with unrefined fuel then is that you have less hydrogen per unit
> volume and more non-fuel particles in the way.

Okay, I just can't stay out of this discussion any longer.

When the unrefined fuel enters the reactor, it takes additional energy
to break apart the moecules and ionize the atoms -- considerable energy
in the case of all non-hydrogen elements.  So, the reactor must be run
at a higher fuel flow rate than was necessary for refined fuel, to get
the same output; or in the case of jump engines, it may be difficult to
get power flow to be well-regulated, depending on vagaries in the mix.

Also, the garbage elements absorb neutrons and other particles; in
general, causing the reaction to be less controlled, and slurping up
still more energy.  The isotope transmutation and added scattering leads
to residual radioactivity of the reactor chamber, and accelerates the
normal plasma bombardment/destruction of the chamber's walls.  The end
result is that the reactor chamber needs replacement much more often,
sensors controlling the reaction are more likely to fail, and with the
increased radioactivity one is more likely to have ionization problems
in nearby electronics and power control circuits.

Commercial engines are DESIGNED to run on refined fuel, so they are
smaller, lighter, less shielded, and have less robust control
mechanisms.  Military drives that run on unrefined fuel are built much
more like a brick caca house, are designed to have the reactor chamber
replaced easily and quickly in the field, have more backup control
mechanisms, plus lots of spares are on board to replace the occasional
failure.  The waste reactor cores can be easily and cheaply placed in a
military rad weapons dump somewhere, and so on.  It's only money, and
the military is allowed to spend lots of it.

> Has anyone considered compressing the hydrogen?

I was always under the belief that fuel hydrogen was stored as a
cryogenic liquid.  Liquids are awfully hard to compress.  The only
possible compression I see possible is to solidify it, which is very
hard to do (need very high pressures) with hydrogen, besides which you'd
need to thaw it out to use it in the engines.

I tend not to worry about deck plans being real accurate; they are there
as additional detail to make the fictional universe more palpable.
Besides, the "rule"books indicate that 10% slop either way on deck plan
volumes is acceptable.  I also figure that there are many nooks and
crannies aboard the vessel which are difficult to depict on deck plans,
but are used by something, either freeing additional room for fuel or
actually used for fuel storage itself... as a case in point, have you
ever done a deck plan of a Scout-shaped ship? With such a shape, it
doesn't translate real well to paper (how big a triangle do I draw to
map deck 1? deck 2? Heck, I'll make a rough guess :-).

James
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Traveller Mailing List Administrator	     James T Perkins @ Tektronix, Inc
[email removed]                      	     Beaverton, Oregon, USA
[email removed]                              "Load Auto/Evade, Beowulf!"