NUMERICAL OPTIMIZATION OF A FISHING VESSEL AS REGARDS TO THE COG POSITIONING.

The application of numerical techniques during the design phase of a ship is rapidly growing up [9, 16, 18, 21]. In fact, since numerical codes are gaining credibility, their employ is widely accepted for preliminary studies. A clever usage of these tools lead to a decreasing of the required experimental tests, and a lower consumption of total budget for this phase is a consequence. Moreover, CFD should play a more attractive role inside an automatic optimization process. Taking apart the "human factor", the CFD tools should suggest hull form variation, to be verified a posteriori with experimental tests, making the field of the investigated solutions wider and wider: new forms completely different in comparison with the modern ships should be produced in this way, because of the fairness judgment of the numerical tools. In the present work the results of an automatic optimization study for a fishing vessel are ex- posed. Seakeeping characteristics are considered as the objective functions of the optimization study. Two COG positions, in order to evaluate the weight distribution effect, are here considered: as a consequence, different geometries are obtained. For the two best hull forms, the total resistance has been derived numerically, in order to verify the effect of the hull form variation on this important parameter, not controlled here, making possible to select the best choice under both the propulsion and seakeeping standpoints.