Sensitivity in numerical analysis of parametric roll

• Parametric rolling is analyzed by different methods, comparing the results.
• Sensitivity of computational results to wave-spectrum modeling and GM variation is introduced.
• The statistical properties of parametric roll showed high sensitive to the time window of simulation.
• Monte Carlo simulation is applied to observe numerical sensitivity.
• This method shows fair applicability for practical use in parametric roll analysis.

This study considers a numerical simulation of parametric roll, which causes serious safety issues for ships. The numerical simulation is carried out in regular waves and irregular waves for two container ships. In regular waves, parametric roll motion is simulated using two different time-domain methods: the impulse-response-function method and the 3D Rankine panel method. These results show good agreement with the theoretical approach using the Mathieu equation. In irregular waves, a systematic study is carried out using the impulse-response-function method for the parametric roll of two container ships, with particular focus on the observation of the sensitivity of computational results to some parameters that can affect the analysis. The parameters considered are the discretization of the wave spectrum, the phase of the wave component, the simulation time window, and the metacentric height (GM). Based on the results of parametric roll simulation, the sensitivity of parameters is discussed, and the experimental results of ITTC's comparative study for parametric roll are compared with present results.