🚀 go-pugleaf

I have followed the flywheel thread with interest.  I have noticed, however,
that there has been a notable lack of citation of experimental results.  While
on vacation in Stanford, I checked out the Socrates catalog for entries on
flywheels.  There was one reference authored by G. Genta.  It has a lot of
interesting stuff in it.

There is a whole section on burst testing and containment.  It turns out that
most of the posts have made some sensible points, but there is no substitute
for actual testing.  There is a setup for destructively testing these things,
and that is extremely interesting in its own right (high power, repairs to the
facility, turnaround, etc).  There is also a reference for Composites (a
journal) for an article on the results of 50 successful burst tests and the
nature of composite wheel failure.  As I thought, the energy is not the main
problem.  The wheel does degenerate into "fluff" which is very easy to contain.
(See the section on containment of much more nasty objects, w/photos.)  The big
problem is that even though the fluff is fairly easy to contain (and 
presumably much of it stays with the wheel), the big problem is how to avoid
problems with torque (not all of the energy is in the fragments).  There are 
sophisticated ways to deal with this which are extremely interesting.  They
cover arragements on how to dump megajoules of energy to the air in times on
the order of 30 seconds.  There are prototypes in use, but supposedly there is
not a flywheel only car.  There is a hybrid system which gives a 10% increase
in economy where the flywheel is simply used to restart the engine after 
braking.

Before Carl Lydick gets too riled up, there is an opposing viewpoint in a 
neighboring book.  Basically, some engineers study different alternatives for
flywheels to recover braking energy in an electric train.  Composite flywheels
are rejected because of cost and quality problems.  Supposedly, they are almost
impossible to balance.  Thus, the issues of safety are moot.  These guys went
with a heavy slow steel disc.  It turned out to be too costly for retrofit.
They have pictures.

From the standpoint of engineering, there are many ways to look at things.  A
theoretical viewpoint is fine, but relying solely on theory can cause one to
get blindsided with reality.  For example, the engineering column in the latest
issue of American Scientist has some excellent and entertaining stories.  Of
course, this could be all a hoax, but the books do have pictures and figures.
Also, there are many details about testing which, even if faked, are quite
plausible and interesting.  If someone is interested, perhaps they could
convince another, who has easy access to the Terman Library, to obtain more
details.  My opinion is that they will not work, but are plenty interesting.
    Eric