Development of a numerical simulation for rotating and sliding of the ice floes along a ship hull

In this paper, a numerical simulation to calculate the sliding and rotating phases of the ice broken pieces after bending failure of the plate ice when the ship advances in the level ice field is developed. The motions of the broken ice floes are described by the 3 degrees of freedom (DOF) rigid body motion in 2-dimensional simulation and 6DOF in 3-dimensional one. A quaternion is adopted to describe the position and rotation instead of using the rotation matrix. The ice pieces and the ship hull are represented by the small contact-spheres which are utilized to detect the contact point between two bodies. The contact force between the broken ice piece and the ship hull is dealt with by the impulsive response. The buoyancy force and the fluid force which is described by the simple formula are considered as the hydrodynamic force acting on the ice pieces. The contribution of the fluid flow induced by the ship advancing is ignored. The simulations are carried out in the both of 2D and 3D conditions. The relationship between the motion of the ice pieces and the ice force in the submerging phase is investigated. The numerical results show that the simulation can describe the mechanism of the rotating and sliding of the ice pieces qualitatively, and has high potential to estimate the submerging component in the ice resistance.