Evaluation of resistance increase and speed loss of a ship in wind and waves

Given the indication of the IMO's intent to the application of the EEDI and EEOI, the complete and precise total resistance of a ship and induced speed loss in wind and wave is primarily required. This paper proposed a practicable method to evaluate the total resistance in seaway. Besides the still water resistance, the added resistance due to waves is computed using panel method and the wind resistance is obtained using CFD with the verification of an open wind test and statistical formula. The speed loss is acquired in consideration of the matching of the hull, engine and propeller. A hull optimization method is consequently presented based on the proper resistance evaluation approach. The approach is validated available and the total resistance of a ship could be reduced after hull optimization.