From: mwilson@ncratl.AtlantaGA.NCR.COM (Mark Wilson)
Newsgroups: sci.energy
Subject: Re: Popular Science Fly Wheel Article
Date: 21 Dec 92 14:50:42 GMT
Organization: NCR Engineering and Manufacturing Atlanta -- Atlanta, GA

In <1h3t1nINNddb@sportster.ksu.ksu.edu> camelsho@sportster.ksu.ksu.edu (   James A Seymour) writes:

I used to think highly of Popular Science, if this article is a sample of
their recent product then they have indeed fallen into sorry straights.

|******************** Article Follows *****************************
|                   
|                       FLYWHEEL POWER

|The idea of using a flywheel to store energy is not new, but designing
|a device that works efficciently and safely has proved difficult.

And this article they do not demonstrate that they have solved this
problem.

|To
|power a car, a flywheel battery must be capable of rotating at 150,000-
|200,000 rpm.  If the flywheel is a metal disc, it could break into 
|shrapnel at that speed.  And if it is a spoked wheel, the rim pulls
|away from the hub at high rpms.

Just because your dealing with a spoked wheel and not a disk does not
prevent it from becoming shrapnel in a failure.

|AFS claims to have solved some of these provlems.  For example, the
|new battery's spoke-tube assembly allows the flywheel rim to expand
|without separating from the hub.  And when the rim is spun so fast 
|that it fails, the Kevlar fibers simply turn into "cotten candy,"
|says Edward W. Furia, chairman and chief executive officer of AFS.

This statement shows the CEO either has absolutely no idea of what he
is talking about, or he is lying through his teeth.  Does anyone know if
these guys are currently seeking suckers, I mean investors?  That might
explain the extravagent claims.

|Furia says his new battery could make GM's proposed Impact electric
|car go as far as 600 miles on an overnight charge.  The Impact now
|runs on 32 lead-acid batteries and has a range of about 80 miles.
|Replacing the lead-acid batteries with 20 flywheel batteries, each
|weighting 30 pounds, would also improve the car's acceleration, 
|according to Furia.  He says flywheel batteries have a high power
|density--they can give up energy quickly.

Somebody calculated that the energy necessary to move a car 100 miles
could vaporize 40kg of iron.  For 600 miles, looks like the containment
vessel will have to way more than the car.

|"It's very important to overcome the perception of electric cars as
|glorified golf carts of greenmobiles," says Furia.  "Electric cars
|should be capable of dazzling performance."

A true statement, but it doesn't have anything to do with flywheel
safety.

|The flywheel battery would last about ten times longer than a lead-
|acid basttery--which must be replaced after 25,000 miles.  And since
|it uses no chemicals, it wouldn't create corrowsion or disposal
|problems.

True, but the failure modes are very different.  When the flywheel fails
you won't have to worry about disposing of the car either, you won't
be able to find it.

If they hope to use two counter rotating wheels, they had better put
the wheels in seperate containers.  During a turn the gyroscopic procession
causes one wheel to tilt to the right and the other wheel to tilt to the
left.  When the wheels touch, no more car.

|For now, the flywheel battery exists only as a computer simulation.  
|It will take a bout two years to build a protype for a car, Furia
|estimates.  The battery could also be aused to store electricty
|generated by solar or wind power.--Dawn Stover

Only exists as a computer simulation, now that explains a lot.

After they build one of these light enough to put in a car, and then force
a flywheel failure,  If they live through the experiment, then come see me.
-- 
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
Newsgroups: sci.energy