On the development of fast numerical methods for the estimation of hull girder loads for a flooded ship in waves

This paper reports on fast numerical methods capable of modelling the behaviour of a flooded hull in waves. The focus of the current research concerns the development and the application of such methods for hull girder loads. Prior dealing with damage scenarios, a lightened numerical model for hull girder loads in intact case is proposed, i.e. operating on a reduced number of input data. Four approaches for modelling damaged ship dynamics, based on “lumped mass” technique, are developed and compared, finalized to hull girder outcomes. They exploit different assumptions, in particular on the free-surface inclination and on the amount of flooded water in an open-to-sea compartment. Comparisons with available experimental data are carried out, for the frigate hull named DTMB5415, in head and beam seas. The outcomes of the current research point out the levels of accuracy of the proposed methodologies on ship dynamics and on sea loads according to the investigated wave scenario