Research on ice resistance of an icebreaker during continuous icebreaking

Abstract

Objective In order to accurately assess the ice resistance experienced by the icebreaker during continuous icebreaking while sailing in the level ice zone, and to understand the characteristics of different forecasting methods, this paper uses empirical formula method, numerical simulation method and ship model test method to evaluate the icebreaker's continuous sailing in smooth ice. The ice resistance was predicted. Method In this paper, the nonlinear finite element software DYNA is used to construct ice numerical simulation models based on traditional finite element and cohesive element methods, respectively, to simulate the bending fracture and the interaction process that occurs when the level ice interacts with the icebreaker. At the same time, using the empirical formula method, three different empirical formulas were used to calculate the ice resistance, and the sensitivity analysis of the parameters affecting the prediction results of the empirical formula method was also carried out. Results The study found that ice resistance showed an upward trend with the increase of speed, ice thickness and bending strength. Among them, ice thickness has the greatest influence on ice resistance. Among the three empirical formulas, the prediction results of the Lindqvist formula are closer to the ship model test results, while the Vance and Lewis formulas are more conservative. Traditional finite element and cohesive element methods have more accurate ice resistance prediction results when the thickness is small. When the ice thickness is large, the error is about 25%. In the case of low ice thickness and high speed, the ice resistance value predicted by the cohesive element method is more accurate than the traditional finite element method, and the accuracy error is within 10% compared with the ship model test result. Conclusion In the actual ice resistance forecast, the empirical formula method and numerical simulation method can be combined to take into account the accuracy and efficiency of the forecast results, which has certain engineering application significance.