EXPERIMENTAL INVESTIGATION ON RESPONSE OF SHIP ROLLING MOTION COUPLED WITH LIQUID SLOSHING

Ship motion coupled with sloshing of three partially filled prismatic tanks is analyzed experimentally in a towing tank. The results show that the sloshing can increase the natural period of ship motion and another peak caused by the sloshing inside the tanks can be seen at a lower period. In addition, anti-rolling effect under low filling conditions and enhanced-rolling effect under high filling conditions are observed, depending on the dominant force, namely, the hydrostatic force and the hydrodynamic force for different filling depths. The internal sloshing flow is able to generate the restoring moment and overturning moment at both low-filling conditions and high-filling conditions, respectively, leading to the suppressed and enhanced effect on ship rolling responses. It is also found that if the filling depths of the three tanks are not the same, the ship rolling motion will be reduced significantly, especially at the resonant period of ship rolling motion.