Rotor Dynamics Calculator

Calculate critical speeds, unbalance response, and whirl amplitude for rotating machinery per API 617.

Total rotor mass.
kg
Combined bearing stiffness (both bearings in parallel).
N/m
Mass center offset from geometric center.
mm
Normal operating speed.
rpm
System damping ratio. Fluid film: 0.05-0.15.

Results

1st Critical Speed-rpm
Speed/Critical Ratio-
Unbalance Response Amplitude-μm
Separation Margin-%
References: API 617 — Centrifugal Compressors; Vance — Rotordynamics