Experimental and numerical investigation on ice submerging for icebreaker with 2D model test using synthetic ice

摘要

2D model test using synthetic ices have been carried out in order to provide information on ice submerging regarding an icebreaker advancing into level ice. A polypropylene plate has been used for a synthetic ice. The ship was rigidly towed by the carriage and advances in pre-sawn ice with the constant speed. The ice forces and the motions of ice submerging in different ship and ice conditions such as the ship speed and size of the pre-swan ice were measured. The measured data showed the motions and the ice forces of ice submerging depend on the geometrical conditions between the ship and the pre-sawn ice as well as the ship speed. 2D numerical model that enables simulations of ice force on the icebreaker that is advancing into pre-sawn ices were developed by physically based modelling. The contact force and the friction force act on the contact point between ship and ice. Buoyancy and fluid force described by the simple formula were considered as the hydrodynamic force acting on the ice floe. The numerical results are compared with experimental data. The ice force of the ice submerging of the numerical results roughly agreed with the experimental data qualitatively. The influence of the ship and ice conditions on the ice submerging are investigated. The hydrodynamic force induced by the ice submerging are important role to estimate the ice force as well as friction force.