Impact of bow shape on added resistance of a full hull ship in head waves
Hironori Yasukawa, Masaru Tsujimoto
Abstract
Resistance tests were conducted in regular and irregular head waves to study the impact of the bow shape on the added resistance of a full hull ship with block coefficient Cb=0.87. The study used three different ship models with identical stern forms but systematically altered bow shapes. It was observed that a vertical stem without a protruding bow could help in reducing the added resistance in waves. The reduction ratio was about 20% under both full and ballast loading conditions compared to a normal stem with a protruding bow. The strip method, known as the NMRI method, is applied in addition to the above- mentioned tests to predict the added resistances affecting the ships in regular waves and to clarify the effectiveness and range of application of the method. The NMRI method can qualitatively capture the differences in the added resistances in the bow shape series for a full hull ship. However, the calculations become less accurate under ballast loading condition.