🚀 go-pugleaf

In article <1hcmi5INN7fd@armory.centerline.com>, jimf@centerline.com (Jim Frost) writes:
> I thought it was assumed that the flywheel operated in vacuum?  The
> "shock wave" will be expanding particles thrown off from the wheel
> itself, and the speed will depend on how fast the particle was moving
> when the wheel disintegrated.  I suspect that'll be a whole hell of a
> lot faster than the speed of sound.

Hyper velocity rotor failure will likely include a shockwave in the rotor
itself as a result of the hypervelocity fracture of the material.

> This discussion is great, but as I mentioned before it's also moot
> unless someone's figured out a way to eliminate gyroscopic effects
> from the flywheel.  These would be considerable, you know.

The torque would be less than 250,000 N-m.  (The 250000 comes from a
flywheel 1 meter in radius storing 92000 kCal and spinning 2775 radians/s.
Since angular momentum is energy divided by angular velocity, a more
reaonably sized flywheel (which would necessarily spin faster) would
store the same energy, but result in less torque.  The turn was 90
degrees in 1 second).  This is a lot, but probably could be managed for
awhile.  We can assume that 2 flywheels are mounted with opposing spin,
so net torque is zero, but the frame would be strongly and repeatedly
flexed with 10,000 to 100,000 N-m of torque.  The mounts or frame
would eventually distort or fail.  I don't have any figures for this
sort of failure, so I can't compute when a typical mount might fail.
I would guess it would be a long time, on the order of years, by just
gross comparison to normal engine torque and the failure of engine
mounts.  I assume the flywheel mounts would be designed so as to minimze
torque on the frame itself.


--
Richard Stead
Center for Seismic Studies
Arlington, VA
stead@seismo.css.gov