On the prediction of parametric roll

The numerical assessment of parametric rolling by means of time domain simulations is troublesome. This is due to a number of practical and conceptual problems. Therefore, simple transparent methods that give immediate insight in the characteristics of a particular design are still of interest. The present paper describes a method in which the results of linear calculations on the ship motions are used to estimate hydrostatic stability variations. Following Dunwoody (1989a) the stability variations are translated in a reduction of the roll damping and the safe operational limits of the ship. Numerical results are compared with experimental data.