Non-smooth discrete element method analysis of channel width's effect on ice resistance in broken ice field

A numerical model based on NDEM is used to investigate the effect of channel width on broken-ice resistance in the channel. The model incorporates a limited impulse method to simulate the ice crushing failure. The accuracy of the numerical model is benchmarked against experimental data from model tests conducted on the Araon icebreaker at KRISO. The simulations successfully capture the characteristic effects of channel width on broken-ice resistance observed in the experiment. Beyond benchmarking of the numerical model, this study analyses the force chain characteristics in the broken ice field, revealing the crucial role of force chains in the resistance increase caused by channel width constraints. Building upon the established numerical model, further sensitivity analyses are conducted to investigate the correlation between channel width effect and other relevant factors such as ice concentration, ship velocity and ice thickness. Among these factors, it is found that ice concentration emerges as the predominant determinant of the critical channel width. The increase in ice resistance attributable to the channel width is exacerbated under the condition of thicker ice floes and lower ship velocity, where the occurrence of ice floe rotation is less frequent and the corresponding force chains are stronger and more stable. •A numerical model based on NDEM is established to predict the ice resistance in the channel covered by broken ice.•The numerical simulation shows good agreements with the experiment in terms of the mean ice resistance and the characteristics of ice resistance varying with channel width.•The formation of force chains between ship and channel boundaries is the most important mechanism causing the channel effect.•Ice concentration is the primary factor influencing the critical channel width.•Lower ship velocity and thicker ice floes will exacerbate the channel width effect.