Experimental and numerical investigation of draught and trim effects on the energy efficiency of a displacement mono-hull

The trim influence on the hydrodynamic resistance of a displacement mono-hull, a mini-cruiser, is investigated for various operating conditions. Scale model tests have been carried out at the towing tank of Genoa University, taking into account three displacements (full load and two lighter displacements) at five static-trim combinations (even keel, two trim values by bow and other two by stern). The motivations of the research arise from the considered ship type, because these kinds of experimental studies, for the examined hull form, are not readily available in the scientific literature. The experimental results are discussed in the light of the uncertainty analysis to evaluate the reliability of the measured data, to be used for the development of a decision support system aimed at a proper energy management of the full-scale vessel. As case study, the fuel consumption analysis is reported for a defined route, in order to assess the trim importance on the overall ship energy efficiency.