🚀 go-pugleaf

In article <1992Dec28.220947.19148@michael.apple.com>,
ems@michael.apple.com (E. Michael Smith) wrote:
> 
> In article <1hnnrdINNnna@gap.caltech.edu> carl@SOL1.GPS.CALTECH.EDU writes:
> >In article <1992Dec22.204130.18133@enterprise.rdd.lmsc.lockheed.com>, () writes:
> >=Obviously this fluff created by a failed flywheel is not exactly safe.  But
> >=you contain this fluff inside another carbon carbon shell such that the
> >=expanding hot fluff makes more fluff until the energy is such that it can
> >=be contained by a container.  The object is not to stop the flywheel failure
> >=at any given point, but to slow it down and cause it to loose energy.  
> >
> >Yup.  Now, since someone has calculated that the flywheel is storing enough
> >energy to VAPORIZE 40 kilograms of iron, just how big is your containment
> >system going to be?  Will there be room for people in the car?
> 
> Hmmm ... an interesting question arises from this oft' posted phrase
> 'VAPORIZE 40 kilograms of iron' ...  Since this is only 88 lbs of
> stuff (and my car weighs about 2000lbs) it isn't THAT much of a 
> weight penalty ...  So just how much of a very high heat of vaporization
> substance would it take to absorbe the heat as phase change?  Say, for
> example, water?  (Or whatever is even better suited...).  If one could
> wrap the flywheel in a 200 lb water jacket and still be lighter than
> a lead/acid battery pack, it might still be 'reasonable' ...
> 
> Now, getting all that KE dumped evenly into the water jacket could be
> quite a trick ;-) and will be left as an excersize for the reader ;-) ;-)
> 
> -- 
> 
> E. Michael Smith  ems@apple.COM
> 
> 'Whatever you can do, or dream you can, begin it.  Boldness has
>  genius, power and magic in it.'  -  Goethe
> 
> I am not responsible nor is anyone else.  Everything is disclaimed.

    Well, I just can't let this one pass...I have to add my $.02 to this
*interminable* thread.  Would anyone out there care to be in the same car,
or for that matter within several hundred yards of a car, where 200 lb of
water had suddenly and very rapidly been converted to superheated steam? 
This would convert the whole car and occupents (sp?) to a large
fragmentation grendade.  Just because something is vaporized does not mean
it is rendered harmless; hot, expanding gases are what do the damage in all
explosions.  When water is vaporized, it's volume increases ~1000X, so that
200lb of water(25 gallons) suddenly wants to take up 25,000 gallons; wants
to *bad*.  If constrained to remain at its original volume, it will be at
1000 atmospheres, attained within microseconds.  The pressure vessel
capable of containing this *will* weigh more than a battery pack, or a car.