| With global warming,the arctic shipping route has been improved year by year,and people’s exploration of the polar region has become more and more in-depth,and the research on ships in the ice region has become more and more important.Rafted ice is formed by two or more pieces of ice with the same volume overlapped under the action of wind,waves and flow and then frozen into a whole again.Because it does not need a long time of heat exchange to double the thickness of ice,it may lead to the wrong prediction of ship resistance in the ice area and cause security risks.In this paper,numerical simulation and model test are used to study the failure mode and resistance of rafted ice.Firstly,the computational fluid dynamics(CFD)and discrete element method(DEM)were coupled,and based on the secondary development of STAR-CCM+,the DEM models of layered ice and rafted ice under regular arrangement were established.The accuracy of the coupling model was verified by comparing the numerical calculation results of layered ice with model tests.Then,a numerical simulation is carried out to study the failure mode and resistance characteristics of the ice,and the influence of ship speed and porosity is discussed.Based on the study of layered ice,a numerical simulation is carried out to study the effects of ship speed and porosity on the failure mode and resistance characteristics of rafted ice.Finally,a method for the preparation of the rafted ice model is designed,and a model test of the ship resistance performance in the rafted ice region is carried out,which is compared with the numerical simulation results to verify the accuracy of the coupling model.Through the research of this paper,we hope to provide some reference for the resistance prediction of ships in the ice region. |
