Lateral-boundary interference in pack-ice channels of varying width during ship self-propulsion

Lateral level-ice boundaries in a pack-ice channel constrain pack-ice motion and alter the hull-propeller local hydrodynamic environment, thereby inducing lateral-boundary interference during ship self-propulsion. This study investigates the Korea Research Institute of Ships and Ocean Engineering Container Ship in pack-ice channels of varying width. A coupled computational fluid dynamics–discrete element method is used to simulate self-propulsion at W/B = 1.4, 1.6, 2.0, and 2.5, where W and B denote channel width and ship breadth, respectively, together with an unconstrained condition without lateral level-ice boundaries. The lateral-boundary interference is examined from the perspectives of pack-ice motion, free-surface deformation, stern-flow characteristics, and the resulting propulsion response. Results show that narrower channels restrict the lateral clearing of pack-ice and promote ice accumulation along the hull, which strengthens the interaction among the hull, pack-ice, and lateral level-ice boundaries. As W/B increases, the total resistance coefficient decreases and approaches that of the unconstrained condition. The thrust deduction factor decreases, while the wake fraction increases slightly. A narrower channel shifts the self-propulsion point toward a higher propeller rotational speed. Compared with the unconstrained condition, the rotational speed at W/B = 1.4 increases from 4.80 to 5.77 rps, thrust increases from 22.04 to 37.73 N, and delivered power increases by approximately 110.3%. Propulsive efficiency decreases from 0.790 to 0.651. This study clarifies the influence of pack-ice channel width on lateral-boundary interference during ship self-propulsion and provides guidance for performance prediction and route planning in pack-ice channels.