Theoretical And Experimental Research On Parametric Rolling Of A Container Ship

Based on intact stability criteria requirement, the International Maritime Organization(IMO) is working on developing the second generation of the intact stability criteria,Parametric rolling as a kind of stability failure mode is causing increasing concern toacademics. Parametric rolling is a phenomenon which could cause fatal damage to the safetyof navigation, so do numerical prediction in the design stage to avoid the ships sailing inparametric rolling is a very significant work.This paper takes a large container ship model as the object of the research, series ofexperiment has done under heading wave in the towing tank. According to the condition ofthe parametric rolling there are regular and irregular plans for the experiment，observe thephenomenon and record data. Analysis the data and discuss the needing conditions forparametric rolling, the occurring mechanism, relationship between the encounter period andthe roll natural period and the wave parameters (wave period, the wavelength, the waveheight) to the parametric rolling of the relevant influence of the phenomenon. Speed change,whether to add the initial disturbance on parametric rolling effect occurs, the relationship ofthe roll motion and other motions and the roll response amplitude trend when parametricrolling happened. On the irregular test, wave spectrum was analyzed to explain why thephenomenon did not occur.Finally using the model which the ITTC recommended for the regular wave in head seasto predict the large container ship of the parametric rolling, the results are compared with themodel test. Through the model test to determine the roll damping，calculate the righting armof different positions of wave with the ship, and the variation of the GM curve. The modelthat the ITTC recommended could predict the occurrence of parametric rolling, but theuncertainly of GM influences lead to this model cannot achieve the final steady-state resultsand will be high forecast parametric rolling response amplitude.