Session: 02-04-02 Extreme Loads and Response 2

Submission Number: 180162

Interaction of Large Waves and Strong Currents With a Moored Floating Ocean Structure in Drifting Ice Fragments 

All ocean constructions are generally subject to the same local ocean conditions, including currents and waves, all year round. Particularly in the North Sea, the coexistence of nomadic ice fragments under unique conditions, like storm waves or the incursion of large swells, makes loading scenarios extremely complex for any structure in the vicinity. This is because waves and currents alter local wave fields and, consequently, forces acting on the structure. When ice fragments hit a structure, they release a substantial amount of impact forces on the different parts of the structure, which can drastically lower the operational activity of the structure. Reducing greenhouse gas emissions and combating global warming depend heavily on green renewable energy sources. A moored floating structure, which may be viewed as a foundational structure upon which an offshore wind turbine can be installed to generate clean, renewable energy, is taken into consideration in this study. The motions of a moored structure, tensions in the mooring lines, and the loads brought on by large waves, powerful currents, ice, and their interactions are all examined in this study. The properties of the coupled wave-current coexistence field are predicted using a 3D wave-current coexistence numerical tool. The obtained wave field data are then used in OrcaFlex^TM, a commercial tool that simplifies and speeds up computations of structural motions and loadings by using lumped mass elements. By methodically changing the incident wave and current, this analysis was conducted for a variety of scenarios while maintaining the same structure shape, mooring lines, airgap, ice orientations, and still water depth.

Presenting Author: M Hasanat Zaman National Research Council Canada

Presenting Author Biography: Dr. Zaman is a senior research officer in the National Research Council of Canada and has been with this research organization for about 25 years. He has been involved in various ocean hydrodynamic research fields; stability of ocean structures, dynamic positions, marine autonomous surface ships, etc., are a few to mention.

Authors:

M Hasanat Zaman National Research Council Canada
Ayhan Akinturk National Research Council Canada