Experimental Study on the Effect of Bow Hull Forms to Added Resistance in Regular Head Waves

Abstract

The concepts of the bow shape for the reduction of added resistance in waves are applied to the VLCC tanker well known as KVLCC2 and their performance in waves is evaluated by model tests in regular head waves. To identify the small difference of added resistance in waves between the different bow hull forms, the measurement system which allows surge motion is newly designed and used in the present study. Two different bow hull forms for the original KVLCC2 are designed with the concept of Ax-bow and LEADGEbow, which is known as the shape for the reduction of wave diffraction. The effects of Ax-bow and LEADGEbow on the added resistance reduction are significant in the short wavelength range of λ/Lpp < 0.7. From the extended analysis for irregular waves, it is known that the reduction effect is enhanced as sea state increases and the increase of calm water resistance due to the hull form variation is compensated from sea state 4. Ax-bow and LEADGE-bow have the EHP saving of both 0.2% for the sea state 4 and 2.2% and 4.2% for the sea state 5, respectively.ference of added resistance in waves between the different bow hull forms, the measurement system which allows surge motion is newly designed and used in the present study. Two different bow hull forms for the original KVLCC2 are designed with the concept of Ax-bow and LEADGEbow, which is known as the shape for the reduction of wave diffraction. The effects of Ax-bow and LEADGEbow on the added resistance reduction are significant in the short wavelength range of λ/Lpp < 0.7. From the extended analysis for irregular waves, it is known that the reduction effect is enhanced as sea state increases and the increase of calm water resistance due to the hull form variation is compensated from sea state 4. Ax-bow and LEADGE-bow have the EHP saving of both 0.2% for the sea state 4 and 2.2% and 4.2% for the sea state 5, respectively.