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- Newsgroups: sci.electronics
- Path: sparky!uunet!cs.utexas.edu!tamsun.tamu.edu!inetg1!ericc
- From: ericc@Arco.COM (Chang Eric(214)754-3562)
- Subject: some answers to flywheel questions
- Message-ID: <1993Jan6.213500.19890@Arco.COM>
- Organization: ARCO Oil and Gas Company
- Distribution: usa
- Date: Wed, 6 Jan 1993 21:35:00 GMT
- Lines: 44
-
- 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
-
-