The Italian Navy has performed a feasibility study about a new OPV (Offshore Patrol Vessel), characterized by very high maximum speeds and a large differences between cruise and full speed.

An attempt to identify adequately hull forms and to determine the most effectiveness of interceptor device, to be applied on the displacing hull, is developed in this study by the RANSE code CD-Adapco STAR CCM+.

To taking into account the low reliability of numerical simulation to predict the interceptor’s effectiveness, the towing tank experiences, carried out by INSEAN-CNR Rome on the reference hull form, have been compared with the numerical simulations.

Finally different configurations of hull forms are been evaluated to minimize hull resistance. Moreover, with the same aim, a different approaches for mesh (fixed mesh and chimera grid technique) and the different turbulence models were analysed.

 Summarizing, this work is divided into the following parts:

1. towing tank test experiences;
2. choice of the numerical procedure more reliable (by validation with towing tank test);
3. optimization of the hull forms in relation to drag resistance determined at the two operational speeds;
4. identification of interceptor’s good size to be applied to the final hull form.

Tests and numerical simulations are performed on model length 8.3 m (14.931 scale), i.e. Rn > 2.1 10⁷.