What is a flywheel used for?

A flywheel stores rotational kinetic energy to smooth out speed fluctuations caused by uneven torque (e.g., piston engines) or intermittent loads (e.g., punch presses). It acts as a mechanical energy buffer.

What is the coefficient of fluctuation?

C_s = (ω_max − ω_min)/ω_avg is the ratio of speed variation to average speed. Typical values: punch press 1/10–1/50, pumps 1/100–1/200, precision machinery 1/300–1/1000.

How do I size a flywheel?

I = ΔE/(C_s × ω_avg²) where ΔE is the maximum energy fluctuation per cycle. For a solid disk, I = mr²/2, so mass m = 2I/r². A heavier rim (hollow disk) is more efficient.

Flywheel Energy Storage Calculator

Calculate flywheel kinetic energy E = (1/2)Iω². For solid disk: I = (1/2)mr². Determine required flywheel size from coefficient of fluctuation C_s = (ω_max−ω_min)/ω_avg and energy requirement.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)

σy — Normal Stress Y (MPa)

τxy — Shear Stress (MPa)

⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.

How It Works

Calculate flywheel kinetic energy E = (1/2)Iω². For solid disk: I = (1/2)mr². Determine required flywheel size from coefficient of fluctuation C_s = (ω_max−ω_min)/ω_avg and energy requirement

Each component has a specific meaning:

Coefficient of fluctuation C_s = /ω_avg — The coefficient of fluctuation c_s = /ω_avg recorded for the patient or scenario being assessed.
Energy requirement — The energy requirement recorded for the patient or scenario being assessed.

Note: Interpret the flywheel energy result against the clinical thresholds and context described above.

How to Use

Enter the coefficient of fluctuation C_s = /ω_avg, energy requirement for the patient or scenario you are assessing. Calculate flywheel kinetic energy E = (1/2)Iω². For solid disk: I = (1/2)mr². Determine required flywheel size from coefficient of fluctuation C_s = (ω_max−ω_min)/ω_avg and energy requirement. Use the flywheel energy result to inform your clinical assessment.

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