🚀 go-pugleaf

In article <1992Dec16.192456.6261@news.cs.brandeis.edu>,
 andyh@chaos.cs.brandeis.edu (Andrew J. Huang) writes:
> <I have to admit an emotional response to this since I think that
> flywheels have tremendous potential.>

The flywheel is a great way to store mechanical energy.  However I'm not
certain about the means for using it.  Somehow the energy must be gotten 
outside of the container.  Mechanical couplings are probably out -- too much
friction.  I suspect that there could be magnets on the flywheel shaft which
would energize a stator coil placed around the outside of the flywheel container
(tolerances would have to be really tight here).  Or perhaps the entire 
alternator could be put inside the container.  

Then we come to electric motors to drive the wheels.  Electric motors have
wonderful torque/speed characteristics for vehicles (they generate maximum
torque just before stall speed, which may make transmissions and clutches
unnecessary) but lousy power density -- look at the size of a 1-hp. electric
motor sometime and tell me how big a motor would have to be to accelerate a
car fast enough to keep up with gasoline-powered ones.  

Maybe hydraulics?  Hydraulic "motors" have the same great torque as electrics
and can be incredibly small for a given power level.  The hydraulic pump
could be inside the flywheel housing; there could be a bypass valve which would
be cut in for "idling".  You'd lose something to the friction of the fluid in
the piping but not much.  

Maybe the greatest thing about the flywheel is that, if you design the system
right, you brake by turning the system back on itself and pumping energy back
into the flywheel.  (This can be made to work for battery-powered electric cars
too, but it works best with the flywheel, since the flywheel can absorb energy
at just about any rate you can throw at it, while there are strict limits on
how fast you can pump watt-seconds into a battery.)  This gets rid of the
second biggest waster of energy in a car (after the thermal losses in the
engine) -- the brakes! 

(I can't help thinking that if we were more creative about ways to use "waste
heat" we would all be a lot richer (and the Arabs would be poorer). )

	--- Jamie Hanrahan, Kernel Mode Consulting, San Diego CA
Internet:  jeh@cmkrnl.com, hanrahan@eisner.decus.org, or jeh@crash.cts.com
Uucp:  ...{crash,eisner,uunet}!cmkrnl!jeh