Numerical shape optimization of a tanker ship hull has been carried out wit
h the aid of computational fluid dynamics (CFD) techniques and experimental
ly verified. The choice of a specific objective function is based on the ne
eds of the user. In the present study, total resistance and wave pattern ha
ve been used either separately or linearly combined. In the optimization pr
ocess, three different algorithms have been tested, coupled together with a
CFD flow solver. A perturbation surface has been used to modify the shape
of the hull, allowing for a sharp reduction of the number of design variabl
es. Accordingly, with different objective functions and geometrical constra
ints, several new optimized shapes of the bulb of a tanker ship have been a
utomatically obtained. Among them, two optimized models have been built and
tested, in the INSEAN towing tank, against the original design. In both ca
ses the measured data have confirmed the success of the optimization proces
s.