From: mwilson@ncratl.AtlantaGA.NCR.COM (Mark Wilson)
Newsgroups: sci.electronics,sci.energy,rec.autos.tech
Subject: Re: Flywheel batteries as EV power source
Date: 18 Dec 92 15:51:27 GMT
Organization: NCR Engineering and Manufacturing Atlanta -- Atlanta, GA

In <1992Dec17.192329.25210@news.cs.brandeis.edu> andyh@chaos.cs.brandeis.edu (Andrew J. Huang) writes:

|In article <1goebdINNik@gap.caltech.edu> carl@SOL1.GPS.CALTECH.EDU writes:
|>In article <1992Dec16.192456.6261@news.cs.brandeis.edu>, andyh@chaos.cs.brandeis.edu (Andrew J. Huang) writes:
|>=In article <1992Dec15.194558.2556@adobe.com> pngai@adobe.com (Phil Ngai) writes:
|>	A lot of it will end up as particle velocity, so now we can
|>	ignore that.

You can only ignore particle velocity if your not standing in front of it.
If these particles are contained within the containment, they will rapidly
give up their velocity to the to containment via collisions in the form
of heat.

|Yes, it is obvious that energy is conserved and no I do not postulate
|a violation of conservation of energy.  But when you take a car going
|80mph and hit a bridge, where does all that energy go?  Into bending
|the sheet metal, breaking glass, throwing tires etc.

The kinetic energy found in a car going 80mph is a tiny fraction of the
kinetic energy that will be found in a flywheel that has enough energy
to push that same car for 100 miles.  Also, the car has a lot more mas
to dissapate that energy into.

|>It didn't just vanish.  And that's a LOT of energy.  And it got dumped FAST.
|>In other words:  BOOM!

|Take a 50's Caddy going 100mph.  Put it into many barrels of sand.
|Did it go BOOM?

The car slowed down over several seconds, this option will probably not
be available to your flywheel.  Part of the energy was dissipated by 
throughing sand everywhich way.  The option of shedding parts is definitely
not available to the flywheel.

|Take a loaded tractor-trailer with bad brakes.  Put it down a mountain
|road.  Send it up the "Failed Brakes" escape road.  Did it go BOOM?

The exact same scenario as above.

|I don't claim to _know_ that an explosion of these flywheels is safe.
|I have read a report in the press that the manufacturer's TESTING
|showed an apparently safe catastrophic failure.  My post was to give
|some _possibilities_ about why the failure was safe.  My post was also
|to counteract the hysterical reaction "I hope they do lots of crash
|testing before letting such a dangerous thing on the roads".  I don't
|see the evidence that it is dangerous.  There is some intuition, some
|hunches, etc, but this has not been born out by the manufacturer's
|_TESTING_.  Whether you believe them or not is another issue.

Was this a flywheel designed as an EV power source, how did they test it,
how much energy was in the wheel when it was tested, how much does the
containment vessel weigh, how thick is it, what material.
Without a lot more information than you have given us, the manufacturers
results are meaningless.  MY intuition tells me that we are dealing with
a killer here, and I will continue to oppose it until presented with
evidence to the contrary.

-- 
Mob rule doesn't become any prettier, just because the mob start to call itself
a government.
It ain't charity if you are using someone else's money.
Mark.Wilson@AtlantaGA.NCR.com
Xref: sparky sci.electronics:20952 sci.energy:6187 rec.autos.tech:16800