Design of a shared suction anchor for 22 MW floating offshore wind turbine

초록

This study investigates the application of a buoyancy-based upward restoring mooring (BURM) system to support a 22 MW-class large floating offshore wind turbine in Ulsan offshore area. Based on fully-coupled load analyses, the horizontal and vertical design loads acting on the shared anchor were determined under BURM conditions. Using these loading conditions, a 10 m-diameter, 30 m-long suction anchor was designed, and the internal stiffeners were arranged to prevent buckling during installation. Subsequently, a coupled Eulerian-Lagrangian (CEL) approach was adopted to simulate large soil deformations and to evaluate the ultimate bearing capacity of the anchor at seven pull-out angles ranging from 0 degrees to 90 degrees. The numerical results were curve-fitted to derive a new capacity envelope, demonstrating improved accuracy compared with conventional empirical formulations. The designed anchor achieved safety factors of approximately 3.5 and 2.5 in the horizontal and vertical directions, respectively, while ensuring stable penetration and buckling resistance. The proposed envelope showed superior agreement with CEL results. Furthermore, anchor load-history analysis confirmed that all design tensile loads remained within the proposed envelope. The proposed numerically derived envelope provides a reliable and cost-effective tool for predicting anchor capacity and designing economical mooring configurations for nextgeneration deep-water floating offshore wind farms.

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