Experimental and computational investigation on wave added resistance for minimum propulsion power of a Suezmax-class tanker

Abstract

This paper shows the comparison results of added resistance in waves of a ship obtained from several methods such as NMRI(National Maritime Research Institute)’s formula, small scale model test and a numerical analysis using 3D Rankine panel method. The Marine Environmental Protection Committee (MEPC) of International Maritime Organization (IMO) statutory requires minimum propulsion power so that a ship can maintain its manoeuvrability even in adverse weather conditions. Minimum propulsion power is in general estimated considering resistance in calm sea, wind resistance and added resistance in waves all together. For the prediction of added resistance in waves, as described in ISO 15016, NMRI formula, small scale model test and direct numerical analysis are allowed. From this study, it is found that minimum propulsion power estimated using NMRI formula which is widely accepted and popular in marine industry is significantly conservative compared with that of a small scaled model test which was carried out by a well-known prominent model test basin. It needs to be investigated further but the deviation of NMRI formula appears to be the fact that it might be calibrated normally at design speed, not minimum speed under minimum propulsion power. On the other hand, it is worthwhile to note that numerical analysis using 3D Rankine panel method is very similar to the model test. In conclusion, numerical method such as Rankine source method can be effectively used for optimum sizing of marine engine in terms of minimum propulsion power. Copyright ？ 2018 by the International Society of Offshore and Polar Engineers