Short Term Prediction

Having completed the Hydrodynamic analysis successfully, the vessel responses in regular (sinusoidal) wave and irregular waves are calculated. Added resistance and dynamic loads can be calculated here if required.

For the regular response calculations, loading condition information is required (including a weight distribution if dynamic loads are to be calculated). In addition, vessel speeds need to be input. (see Seakeeping Dialog - Regular Data Tab).

Motion calculations are based, by default, on theory provided by Vugt’s References 45. A different formulation is also provided, based on the more widely known Scores method. One of these methods should be chosen.

In addition, active fin stabilizers and additional damping due to bilge keels can be included.

For Irregular response calculations, the RAO’s previously calculated are combined with a Wave Energy Spectrum and Wave Spreading function.

In addition, combinations of the six degrees of freedom motion may be made at various locations of interest, to produce for example that total absolute vertical motion (that means, taking into account the heave, pitch and roll motions) at a defined location on the vessel.