A Boundary Element Method for Motions and Added Resistance of Ships in Waves

The accurate prediction of ship’s resistance in waves is nowadays of increased importance, since it greatly influences the ship’s performance regarding sustainable service speed and fuel consumption in seaways. It is well known that added resistance can be regarded as the longitudinal component of the second order mean force acting on a ship in waves. It is computed from the first order ship motions. To this aim to obtain an adequate evaluation of the added resistance a reliable prediction of ship motion is necessary at first. Then the added resistance is determined by integrating the second-order pressure on the body surface. The purpose of this paper is to present a methodology for the prediction of motions and added resistance by a three dimensional panel method and to discuss and validate its results against experimental data. The added resistance determined by such a methodology is corrected using a semi-empirical method to allow for the wave reflection in short waves.