HomeCalculatorsPitch RAO - Linear Approximation

Pitch RAO - Linear Approximation

Linear pitch RAO at a given frequency using SDOF damped oscillator approximation - preliminary pitch-motion estimate for seakeeping analysis.

PitchRAOSeakeeping
Pitch RAO
3.264rad/m
Formula, assumptions, and limits

Full strip-theory pitch RAO has heave-pitch coupling. Containerships pitch > 3° in head seas cause green water on deck. Pitch sync resonance near natural period (typ. 6–10 s).

Symbol legend

SymbolMeaningUnitSource
Natural pitch frequencyrad/sgyroscopic moment of inertia
Damping ratio - strip theory viscous + wave