Comparative study on computation of ship added resistance in waves

Recently, the design of commercial ships that produce less greenhouse gas has been of great interest in naval architecture fields. Ship designers are asked to find optimum hull forms with minimum resistance in ocean waves. An accurate computation of added resistance, therefore, is getting more important for the prediction of power increase in random ocean waves. This study focuses on a comparison of the computational results of added resistance on ships in waves. To calculate added resistance, three different numerical approaches are applied: the strip method, the Rankine panel method, and the Cartesian grid method, which solves the Euler equation. In order to predict added resistance, near- and far-field approaches are adopted in the strip and Rankine panel methods, while added resistance is calculated directly in the Cartesian grid method. The computational results are validated by comparing them with experimental data on Wigley hulls, Series 60 hulls, and the S175 containership, and show reasonable agreements for all models. The study is extended to the analysis of added resistance in short wavelengths; therefore, the established asymptotic methods for short waves are examined.