Give me the flywheel diameter and weight and I'll figure that out for ya, Mike. Of course, if you can also give me the cross-sectional mass profile or at least a centerline cross-sectional view with the mark-space ratio of the cooling fins, it'll be a much more accurate answer.
Here's an interesting one. When William Weldon of the University of Texas was doing work for the government on the "EM" or "Rail" gun (which uses an electrical pulse to propel a plastic cube projectile), most of the work involved developing an extremely well controlled, high energy pulse in the Megajoule power range (a Megajoule is equivalent to 1 million Watt-seconds, a sh!tload of energy). This kind of power, used to propel a 3 inch solid plastic cube (think Rubic's cube) down a set of 15 foot rails, was capable of "muzzle velocities" of over 25,000 fps. I don't know how many grains a cube that size weighs, but since energy is proportional to the square of the velocity, it's not hard to understand why this plastic cube could penetrate 6" of armor plate. One energy source that proved viable was a special motor/generator that spun a 3 foot diameter, 300 lb. flywheel at 3600 RPM. The series resistance of its windings was so low, and its magnetic coupling was so good, that when the gun was fired, the flywheel would come to a full stop in less than 1/4 of a revolution. A few people were injured and many flywheels were scattered because of the extreme deceleration before they got the design correct. I built a capacitor banked rail gun some time ago and ended up with 26 stitches over my eye when it bounced a 2 inch cube off of a cement wall and directly back at me. A trip to the hospital and a catcher's mask later, the bugs were worked out and she was firing the cubes across a 300 yard pond and through 12 inch pine trees on the other side. My friend's chronograph had the velocity at slightly over 7000 fps.
Great chainsaw stuff, eh?
