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- From: whit@carson.u.washington.edu (John Whitmore)
- Newsgroups: sci.electronics,sci.energy,rec.autos
- Subject: Re: Flywheel batteries as EV power source
- Date: 7 Jan 1993 22:06:02 GMT
- Organization: University of Washington, Seattle
- Lines: 32
- Message-ID: <1ii9gaINNjts@shelley.u.washington.edu>
- References: <1hnnrdINNnna@gap.caltech.edu> <1992Dec28.220947.19148@michael.apple.com> <drury-070193073338@esrfd.es.dupont.com>
- NNTP-Posting-Host: carson.u.washington.edu
-
- In article <drury-070193073338@esrfd.es.dupont.com> drury@esvax.dunet.dupont.com (Robert F. Drury) writes:
-
- {responding to scenario that vaporizes 200 lb of water when
- a rotor fails}
-
- > 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.
-
- There was such a pressurized superheated mass of water here
- in Washington, which burst about a decade ago. The superheated water
- was moist dirt, and the containment vessel was Mount St. Helens.
- People died five miles away, and forests closer by (half a mile
- or so) were converted into toothpick-size splinters.
-
- The local seismologists valiantly refused to tell reporters the
- energy yield of the explosion in any terms other than SI units.
- I converted, though: it was about twenty megatons.
-
- There's a dome swelling in the caldera; Mount St. Helens
- might be back up to its original altitude again some day.
-
- John Whitmore
-