Model Tests On Ice Resistance Of An Icebreaking Ships With Different Ice Drift Angles

The Arctic sea ice is in the drift motion state for a long time affected by the wind field and the ocean current.The ice drift movement has a significant effect on ice-ship interaction when icebreakers are navigating in Arctic waters.Especially when the directions of ice drift and ship heading are not in the same line,the bow,midship and stern will encounter the ice sheet directly.At this time,the failure modes of ice have undergone major changes,which will have impact on ship resistance.Therefore,the ice-ship interactions with different drift angles are studied by model tests in this paper.When the ship is straight sailing in the ice area,the ice load mainly concentrates on the bow area,and the failure mode of ice shows a composite mode,splittingcrushing-bending.While the midship and stern are located in the open channel,and only occasionally encounter the impact of small ice pieces.So we focuses on the ice load distribution in the bow and the total navigation resistance under this circumstance.In this paper,the navigation resistance of the ship and the breaking ice force of the bow are studied,and the proportion of the breaking ice force in the total navigation resistance and the variation of the proportion with the speed are analyzed.When the ship is sailing in the ice area with a drift angle,the bow,midship and stern will be in direct contact with the ice.At this time,the failure mode of the bow area is changed to crushing-bending mode,while the midship area is mainly subjected to crushing-bending failure,and the failure mode of the stern area is dominated by crushing failure.In this paper,we focus on ice resistance and the distribution of ice load,and analyze the influence affected by ice drift velocity and navigating speed.In this study,we summarize that the distribution characteristics of ice loads can be divided into two types,line load and local point load.Both the speed and the drift angle will affect the length of the line load,the magnitude of the line loads and point loads,and the probability of the line loads and point loads.The present research works on the influence of these two loads are still unable to make an effective assessment and the relevant research works need to be carried out later.