Stochastic averaging for estimating a ship roll in random longitudinal or oblique waves

In this work, the C11 container ship is taken as an example to analyze its rolling performances in random longitudinal or oblique waves. Firstly, a dynamic model of C11 roll in random waves is improved, and it is verified by the model test and numerical simulation. Mathematically, this dynamic model is a one-dimensional stochastic differential equation with random parametric (and external) excitation. Secondly, an enhanced stochastic averaging method is proposed to solve this stochastic differential equation. The validity of the solutions was verified by Monte Carlo simulation. At last, the probabilistic characteristics of the extreme rolling response were investigated based on the calculated results using enhanced stochastic averaging method. According to the analysis, some advices for ship's manoeuvring can be put forward when ships are navigating in random waves.

Automated summary

This study analyzed the rolling performance of the C11 container ship in random waves, proposing an enhanced stochastic averaging method to solve the stochastic differential equation for extreme rolling response. The validity of the solutions was verified through model tests and Monte Carlo simulations. Recommendations for ship maneuvering in random waves were provided based on the probabilistic characteristics of the extreme rolling response.