CFD-DEM Numerical Simulation of Ship Resistance and Contact Loads in Waves and Randomly Distributed Broken Ice

This study develops a coupled ship-wave-random floe ice-water numerical model to investigate the complex hydrodynamic response of a ship under the combined action of waves and broken ice, while addressing the inability of conventional floe arrangements to represent the random spatial distribution of floes in actual marginal ice zones. The CFD-DEM (computational fluid dynamics-discrete element method) approach is used to simulate collision, compression and sliding between the ice floes and the hull, and to examine the effects of wavelength, wave height and floe ice concentration on contact loads and total resistance.

The results show good grid convergence, with a GCI value of 5.328 x 10^-4; subsequent simulations use approximately 4.2 million cells and a time step of 0.005 s. The random floe ice field causes the ship-ice contact force to exhibit pronounced transient pulses. When the wavelength increases from 3 lambda to 4 lambda, the mean total resistance is approximately 840 N; when the wave height increases to 0.08 m, the total resistance is approximately 940 N; and when the floe ice concentration increases to 80%, the total resistance is approximately 920 N. The results indicate that wave height and floe ice concentration are the dominant factors governing the ship hydrodynamic response, while the random floe ice field enhances the nonstationarity and uncertainty of ship loading.