NetNews Usenet Archive 1992 #31/NN_1992_31.iso/spool/sci/electron/21567

Internet Message Format | 1992-12-25 | 3.5 KB

Xref: sparky sci.electronics:21567 sci.energy:6447 rec.autos:30523
Newsgroups: sci.electronics,sci.energy,rec.autos
Path: sparky!uunet!paladin.american.edu!howland.reston.ans.net!wupost!emory!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Flywheel batteries as EV power source
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Date: Fri, 25 Dec 1992 13:44:59 GMT
Lines: 57

In article <[e-mail]> [e-mail] (Brian Barkey) writes:
>In article <[e-mail]> [e-mail] (Mark Wilson) writes:
>>In <[e-mail]> [e-mail] (Troy Frericks) writes:
>>
>>|>If I were a terrorist, I would drool at the thought of being able to
>>|>get such wonderful bombs so easily... All you'd have to do is arrange
>>|>for the vacuum valve to be opened on command or the magnetic bearing
>>|>to be turned off, etc.
>>|>
>>|>BOOM!
>>
>>|Modern composit materials, when used in a flywheel, will disintegrate
>>|with such a failuar.  This bomb would be about as wonderful as some
>>|fiber-glass insulation falling out of your attic.
>>
>>You haven't been listening have you?
>>It doesn't matter what form the flywheel takes after disintegration.
>>It could even turn into a gas or sub-atomic particles.  What causes the
>>BOOM is all of that kinetic energy being turned into heat.
>>
>    And gasoline isn't explosive?
>    I may be mistaken but any power source capable of propelling
>    a ton or more at speeds greater than 50 mph for hundreds of
>    miles must have a significant amount of energy in it.
>
>    Brian Barkey

You don't understand. The gasoline *does* contain the same amount of
energy as the flywheel, that's the whole point of the exercise. But
liquid gasoline can't explode. Only gasoline vapor properly mixed
with oxygen, 14:1 air/fuel ratio, can explode. When it's arranged
thusly it's called a FAE bomb. When the US dropped one during Desert
Storm, British troops radioed their headquarters and reported that
the "bloody yanks" were using nukes on the Iraqis. It's damned difficult
to get the proper mixture outside an engine, that's why there's all
that monkey motion with carburetors and fuel injectors. In a collision
that ruptures a gasoline tank and vaporizes a tiny amount of the gasoline
and ignites it, you get a fire that burns for half an hour or more as
the heat of the flames vaporizes more of the liquid gasoline. The mixing
with air is very inefficient and the resulting flames are very smokey
because of incomplete combustion, and not terribly hot. It's still hot
enough to melt steel however.

Now with the flywheel failure, all the energy is released at once.
The only difference between a fire and an explosion is the *rate*
at which it occurs. This time the timescale is microseconds. You
wind up with an explosion that is about equivalent to 200 pounds
of dynamite. That's about what the typical terrorist car bomb
uses. 240 Marines died when one was driven to their barracks
in Lebanon.

Gary
--
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