Ideal rigid-body mechanics — arithmetic check
Flywheel Rotational Energy Arithmetic
Compute stored rotational kinetic energy from a documented moment of inertia or one of two explicitly idealized geometries. This is not a safe-speed,stress or containment calculation.
Arithmetic result
Implemented arithmetic
E=½Jω²
uniform solid disk:J=½mR²
ideal thin ring:J=mR²
Here n is in revolutions per minute,ω in radians per second,J in kg·m²,m in kg,R in metres and E in joules. The disk and ring equations apply only to the stated uniform idealizations rotating about the central symmetry axis. Use direct J for any other geometry,with its source documented.
Mechanics and unit sources
MIT OpenCourseWare,Classical Mechanics §16.3 gives rotational kinetic energy and the uniform-disk central-axis inertia. OpenStax University Physics §11.2 derives J=mR² for a thin hoop. NIST SP811 AppendixB.8 gives lb·ft²→kg·m²,kWh→J and mechanical-horsepower relationships. The implementation uses exact definitions:1lb=0.45359237kg,1ft=0.3048m,1in=0.0254m,1kWh=3,600,000J and1mechanical hp=745.69987158227022W.
What the result does not mean
Stored energy is not automatically deliverable energy. Losses,maximum/minimum operating speeds and conversion efficiency are external. A safe flywheel speed cannot be inferred from one generic hoop-stress equation:real stress depends on geometry,material model,temperature,manufacturing defects,stress concentrations,fatigue,fracture behavior,attachments and containment requirements.
Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
