Motions and Added resistance of Multihull Marine Vehicles at high speed: Numerical and Experimental Results

The purpose of this paper is to address the evaluation of motions and added resistance in peculiar applications regarding monohull and multi-hull configrations, which can be characterized by high speed and interaction among hulls. To this aims, experimental values regarding vertical motions and added ressitance in waves of monohulls, as well as catamarans and trimarans were collected. A numerical method, based on 3D Rankine sources was also used. This was initially developed to treat steady waves and then extended to deal with the problem of unsteady radiated and diffracted waves and to compute ship motions. Recently, also the capability to compute added ressitance has been developed. The proposed paper after a short theoretical outline of the numerical method, will present and discuss vertical motion response amplitude operators and added resistance values, for the case of a monohull, a catamaran and a trimaran.