# Flywheel energy

1. Jul 11, 2007

### khoopes01

Our air motor has 2 cylinders and is a low rpm device. It therefore
needs a flywheel to store enough torque to get the crankshaft
past the dead spots at 10 degrees before and after top dead center and
10 degrees before and after bottom dead center.

My question is how to calculate the torque available in a solid cylindrical
flywheel in terms of its diameter, length, density, and RPM.

2. Jul 12, 2007

### mgb_phys

It depends on the design of the flywheel, basically mass at the outer rim where it is going faster has more effect.
There are formula for simple solid disks, cyclinders etc. I can't get the formula writer to work but this link is here http://en.wikipedia.org/wiki/Flywheel

3. Jul 12, 2007

### khoopes01

Thanks, that did it

Thanks - you got me off the dime and I have my answer - is amazing what
the squared term does to flywheel energy. We has a 60 pound flywheel
on the cankshaft and it wasn't getting the job done. A 40 pound flywheel
rotating at 20 revs/second gave us more torque than we need.
Thanks again
Ken Hoopes
Chief Engineer HUE corp

4. Jul 12, 2007

### mgb_phys

It is! There are proposals to use flywheels as alternatives to diesel generators for backup power - a few tons of flywheel at 10,000rpm is a lot of energy!