The aim of work is to study and standardize the operating modes to do viscous simulations with a rational approach with
low cells-number, for carrying out quickly the calculations, without any necessity of super-computers. This methodology
involves the study of different hulls, displacement and planing, evaluating a system of localized mesh-sizing of the
computational grid that could be standardized for each type of examined hull.In addition a protocol to get a good simulation
in the shortest time possible is attempted. In the first part of the study 3-DOF simulations for evaluating trim, resistance,
pressure field and waves of a series of vesselswere carried out. Then the numerical results were compared with experimental
towing tank tests. Finally, the method was applied for searching the best dynamic trim for some displacement and semidisplacement
hulls.
