Numerical investigations of the restriction effects on a ship navigating in pack-ice channel

Abstract

This paper adopts Computational Fluid Dynamics (CFD) method and Discrete Element Method (DEM) to simulate a ship navigating in pack-ice channel considering the effects of channel restriction. First, from the simulations of the ship sailing in open-water channel by CFD, it is found that the effects of channel width on water resistance is more pronounced than the impacts by level-ice thickness. Then, based on the stable and converged flow field obtained by CFD simulations, the CFD-DEM coupling method is applied to reveal the effects of channel width and level ice thickness on ship-ice-water interactions and ice resistances at different ship speeds. The results indicate that as the channel width decreases, the accumulation of pack ice in the areas of bow and midship intensifies. The ice resistances on the bow and midship increase notably, and the lateral ice forces exhibit pronounced asymmetric and random characteristics. In extremely narrow pack-ice channels, lower ship speed results in lager ice resistance and lateral ice force on the ship. In addition, as the level ice thickness decreases, the pack ice is more easily squeezed below the level ice, resulting in the decreases of ice resistance and lateral ice force.