Experimental and Numerical Analysis of the Roll Decay Motion for a Patrol Boat

An experimental and numerical study of the free roll decay motion for a vessel of the Italian Navy is presented. Experimentally both sea trials and model scale tests have been carried out; numerical analysis has been performed by means of unsteady RANS simulations. The focus is on the analysis of the roll motion coefficients (damping and period of oscillations) at different Froude and Reynolds numbers. To this aim, experiments and numerical simulations were carried out at different Froude and Reynolds numbers. Sea trials were carried out on the Italian Navy ship Comandante Bettica in the Mediterranean Sea, close to the coast of Sicily; models experiments were performed in the towing tank at INSEAN. Computations were carried out by means of an inhouse unsteady RANS solver.