ENGINEERING – MECHANICAL ENGINEERING CALCULATOR
Flywheel Mass
A precise tool.
What is the Flywheel Mass & How does it work?
The coefficient of fluctuation (C) quantifies the allowable variation in stored kinetic energy of a rotating flywheel during each cycle. Keeping C low ensures smooth power delivery and reduces stress on the shaft. The kinetic energy stored in a flywheel is E = frac{1}{2} I omega^{2}, where I is the moment of inertia. For a solid disc, I = frac{1}{2} m r^{2}. By rearranging these relationships, the required mass to achieve a target C can be expressed as shown below. Using the formula, designers can input the desired operating speed and geometry to quickly estimate the mass needed, facilitating tradeβoff studies between size, weight, and performance.
m = frac{2 C omega^{2} r^{2}}{1}
m = required flywheel mass (kg)
C = coefficient of fluctuation (unitless)
omega = angular velocity (rad/s)
r = radius of the flywheel (m)
C = coefficient of fluctuation (unitless)
omega = angular velocity (rad/s)
r = radius of the flywheel (m)
Parameters
Result
β
Frequently Asked Questions
What is the formula for calculating flywheel mass?
The formula to calculate flywheel mass is m = frac{2 C omega^{2} r^2}{g}, where C is the coefficient of fluctuation, Ο is the angular velocity, r is the radius, and g is acceleration due to gravity.
How does the coefficient of fluctuation affect flywheel mass?
A higher coefficient of fluctuation requires a greater flywheel mass to maintain smooth power delivery and reduce stress on the shaft.
What is the moment of inertia for a solid disc?
The moment of inertia (I) for a solid disc is given by I = frac{1}{2} m r^2, where m is the mass and r is the radius of the disc.
Why is it important to keep the coefficient of fluctuation low?
Keeping the coefficient of fluctuation low ensures smooth power delivery and reduces stress on the shaft, leading to more efficient operation of machinery.
How does angular velocity impact the flywheel mass calculation?
Angular velocity (Ο) has a significant impact as it is squared in the formula. Higher angular velocities require larger flywheels to store sufficient kinetic energy.
What are the units for the coefficient of fluctuation?
The coefficient of fluctuation (C) is typically dimensionless, expressed as a ratio or percentage.
Can this calculator be used for any type of flywheel?
This calculator is specifically designed for solid disc flywheels. For other shapes, the moment of inertia formula would need to be adjusted accordingly.
Results are for informational purposes only and do not constitute professional advice.