Open Collections

Abstract

In the current work, we present fully coupled 3D numerical models of a hierarchy of problems pertaining to Arctic shipping, predicting hydrodynamic resistance on marine structures interacting with ice. A previously developed fully Eulerian phase-field framework is utilized to model the presented problems, spanning local to large scale ice-structure interactions. The present work establishes the versatility of the framework for ship-ice interaction problems, taking a step toward guiding safe and efficient navigation in ice-covered waters. The first part of the study assesses the framework to accurately predict resistance on a ship model in 3D with free surface effects, by tuning numerical parameters. The section begins by verifying the force computation routine and numerical setup with the framework for flow past a stationary cylinder. Resistance on a bluff body and on a container ship, partially submerged in water, are compared with analogous experimental results. We identify coupled requirements for both the mesh and diffuse interface resolutions to accurately predict resistance by adequately capturing complex fluid-structure interaction (FSI) and free surface effects. In the second part of the study, we present hydrodynamically mediated ice-structure interactions of two different regimes, highlighting the versatility of the framework. We first model the force induced on a marine structure, such as a thruster or a bulbous bow, when it collides with a heavy ice block under water. The peak force and momentum transfer during collision compare reasonably well with an experiment conducted using real sea ice. We utilize the setup to investigate the effect of sea ice shear modulus and collision speed on the collision force and impulse. Finally, we present our technique using the framework to model continuous ship interaction with a drifting ice floe field, mimicking long range transit of an ice-going vessel. The setup captures the rich interactions that are fully coupled between ship, ice, water and air, with implications on the stress distribution on the hull. We examine the effect of ice field concentration and flow speed on the characteristics of the temporally oscillatory resistance, highlighting their importance in constraining operability margins in a given ice field.