Experimental Study on the Longitudinal Ship Motions of Catamaran using the TankSide Wall

In the previous paper, the authors investigated the relationship between the ship motion and the critical frequency of the side wall effect on the longitudinal ship motions by shifting a model from the center line of the tank to a tank side wall.In this paper, the authors applied this model setting method, called Shift in the previons paper, to the test for the longitudinal ship motions of catamaran.Two kinds of experiments were carried out in this paper. One was the forced oscillation test, Pure Heave, for the catamaran model whose distance between twin hulls was 2 P. The other was the forced oscillation tests, Pure Heave and Pure Pitch, and the longitudinal ship motion test in waves for one of the twin hulls of catamaran, which was set at a distance P from the tank side wall.Beside the two kinds of experiments above mentioned, the usual forced oscillation tests, called Center in the previous paper, were also carrid out.Then the comparison between the results obtained from the two kinds of experiments was made with respect to the transfer functions and the coefficients of the equation of the motion.The authors could certify that there was hardly difference between the results obtained from the two kinds of experiments, called Catamaran and Shift in this paper.