Free Flywheel Kinetic Energy & Inertia Calculator
Calculate mass moment of inertia, stored rotational kinetic energy, rim surface velocity, and centrifugal burst stress for flywheels.
⚙️ Flywheel Geometry & Speed
📊 Energy & Mechanical Stress
Frequently Asked Questions
Why do rimmed flywheels store more energy than solid disks of equal weight?
Moment of inertia depends on radius squared (J = M × R²). In a rimmed flywheel, almost all the mass is concentrated at the outermost perimeter where velocity is highest, providing up to nearly double the inertia of a solid uniform disk of identical mass.
What is the safe speed limit for a cast iron flywheel?
General engineering safety codes limit one-piece cast iron flywheels to a maximum rim speed of 6,000 feet per minute (approx 30.5 m/s or 100 km/h).
How do you calculate the tip speed of a flywheel?
Rim Tip Speed (m/s) = (π × Diameter in meters × RPM) / 60. In Imperial: Tip Speed (ft/min) = (π × Diameter in inches × RPM) / 12.
How does a flywheel smooth out an engine or compressor?
When the piston fires during the power stroke, the flywheel absorbs excess torque with only a tiny speed fluctuation. During the compression and exhaust strokes when no power is produced, the flywheel delivers its stored kinetic energy to keep the crankshaft rotating smoothly.