Numerical Analysis on Added Resistance of Ship by 3-D Green Function Method

Abstract

This paper deals with the numerical analysis on added resistance of a ship by 3-D Green Function Method. Linear potential theory has been used to describe the fluid motion and 3-D sink-source technique with forward speed has been applied to determine hydrodynamic forces for surface ship advancing in waves at constant speed. After solving the motion equation in frequency domain, radiation potential due to motion responses have been calculated to obtain the total potential of the flow field. Then, total potential and its derivatives have been obtained to assess the added resistance in waves by near field approach. To show the validity of the numerical code, the present numerical results for motion responses and wave loads on ships have been compared with experimental data as well as some numerical results by different approaches. Then the added resistances given by present numerical calculation by 3-D Green Function have been compared with some classical 2-D methods as well as experimental data for Series 60 ships. Finally the present numerical calculations have been applied for fuller form slow speed vessel where the classical 2-D methods usually fails to give good results due to their inherent limitations. The numerical results suggest that better agreement have been achieved in many cases using present full 3-D Green Function method.