Analysis Of The Pack Ice Trajectory And Its Interaction With Ship-propeller

As we all know,due to the exploitation and use of human transition,land resources are gradually depleted,so more and more people focus their attention on the ocean.And with the polar ice melting,the ice coverage decreasing,provides the possibility for the Arctic waterway navigation and energy utilization.In addition to the impact of the Arctic rights disputes,China's Bohai and the East China Sea will be frozen in winter,so the study of the ice ship is very important.The complexity of the ship's working conditions in the ice area makes it more demanding on the propeller.Especially in the crushed ice area,some ice will move along the bottom surface of the ship to the front of the propeller,and the propeller interfere with each other,affecting its hydrodynamic performance,and even produce serious cavities and noise.In order to avoid the damage of propeller,it is important to study the track of ice and the interference of ice-propeller.Based on the viscous fluid mechanics and the overlapping grid method,the hydrodynamic performance and the surrounding flow field characteristics of the ice propeller under different working conditions are simulated and forecasted in this paper.Based on the comparison,the feasibility of the method is verified,and then the influence of the ice motion to the different axial and radial positions on the thrust,torque and efficiency of the propeller is discussed.At the same time,the influence on the flow field after the propeller of the ice in different positions is analyzed.In order to simulate the ice movement more accurately,this paper chooses the DFBI motion model to calculate the mutual interference of the ice-propeller in the unconstrained state,and analyzes the motion state and the force of the underwater ice under propeller suction.By controlling the propeller speed and the position of ice to achieve more working conditions.According to the calculated results,the probability of colliding with the propeller when the ice is located in different spatial positions is summarized,which provides a reference for the design of propeller.Then,using the discrete element model combined with the Eulerian multiphase flow to calculate the interaction between the ship and ice.The stress of the hull under different speed and different ice levels is calculated,and the motion response of the ice during the ice collision is discussed.It explained the reason of the change of the ice resistance and the movement of the ice for the optimization of the ship intuitively.In the end,the recommendations for the optimization of ship type in ice and the propeller design are given.