AN INVESTIGATION ABOUT ADDED POWER IN HEAVY WEATHER FOR PASSENGER SHIPS WITH FOCUS ON WIND EFFECT

The passenger ships propulsion performance in heavy weather condition has been investigated, using full scale data recorded on board. An “added power” coefficient has been identified, inclusive of both wind and waves effects, in relation also with the frequency of occurrence for each relative wind direction value. Moreover, due to the importance of the topside exposed surface, typical feature of passengers ships (e.g. cruise ships and ferries), attention has specifically been paid to the wind contribution. An attempt to derive the solely effect of wind action from a full scale data-sample has been finalized; in this perspective non-dimensional coefficient of wind force has been derived and plotted as a function of wind relative direction angle.