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

1. Jun 9, 2016

### krishna patel

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?

2. Jun 9, 2016

### CWatters

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.

3. Jun 10, 2016

### Baybora

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 ...)