# How to calculate how much power required to turn a flywheel?

How to calculate how much power required to turn a flywheel at constant velosity ? Suppose I have a flywheel of 24 inch diameter, width 5 inches,50kg and constant angular velosity is 1500 rpm. How do I calculate the required power (HP) to turn this or any other with different values?

CWatters
Homework Helper
Gold Member
If there are no losses (eg no friction or air resistance) then it takes no power to keep it running at a constant angular velocity.

If there are no losses you can use the formula

Energy= 1/2 * I * W2

I= m*r2 * constant depending on shape

then divide by the time you want it to reach the angular speed you want (e.g in 10 sec ...)