The Seakeeping Investigation of an Inverted Bow Hull by Experimental Method

This paper investigates the heave and pitch motion responses of an inverted bow hull. The experimental data were obtained from seakeeping tests with two scaled models of reference fishing vessel NA8-14 BSRA. The bow shape of the models is redesigned by inverted shape in two angles of 45 and 60 degrees. Several tests were conducted on the models at different speeds of 0.6, 0.9, and 1.2.m/s. Generated waves in the towing tank are of the regular type with the wavelength changing from 0.6L to 1.6L by an increment of 0.2L m. The amplitude of the waves was equal to either 35 mm. The heave and pitch response amplitude operator (RAO) versus no dimensional frequencies are presented. The investigations demonstrated that by decreasing inversion angle of bow to 45 degrees motions of the model improved. The results also showed that the interactions between the motions responses leads to the frequent appearance of “Kinks” in a coupled form with the responses of other motions .