Efficient discrete element simulation of managed ice actions on moored floating platforms

Abstract

The current design standard lacks the detailed approach to estimate managed ice actions, which in turn forces the industry to rely on ice basin model tests and calibrated numerical simulations. To address the need for a reliable assessment of managed ice actions on large-scale floaters, this paper proposes an efficient two-dimensional discrete element simulation with polygonal elements, which integrates smoothly with a mooring system modeling and a hydrodynamic force representation. The study aims at establishing a range of numerical parameters suitable for managed ice, as well as the boundaries within which the two-dimensional assumption remains acceptable. The study includes validations against the empirical data on isolated ice impacts and the towing model test conducted in the Hamburg Ship Model Basin (HSVA), for which the discrete element simulations demonstrate reasonable agreements. Using this validated tool, this paper conducts a case study using a hypothetical floater based on the Kulluk, a heavily studied conical drilling platform with years of deployment in the Arctic. The study examines the effect of different ice and mooring characteristics on the simulated load, which provides insights on the design of floating platforms and its mooring systems for managed ice conditions.