Abstract This study addresses the challenges of positioning design complexity and multi-coupling analysis for ultra-long scale multi-module floating breakwaters in the complex environment of harbor basins by innovatively proposing an asymmetric Y-shaped composite mooring system. A time-domain coupled numerical model was established based on three-dimensional potential flow theory, with physical model tests verifying module damping parameters (errors below 7%). The numerical approach considers inter-module coupling of the floating breakwater and its dynamic interaction with the mooring system, enabling comprehensive multi-floating-body coupled dynamic simulations. Comparative analysis of mooring line tensions under typical operating conditions further investigates the safety performance and positioning ability of this mooring setup under extreme beam sea and oblique sea states. Key findings reveal: (1) The proposed mooring system overcomes the limitations of traditional symmetric configurations, effectively adapting to multidirectional wave load characteristics; (2) Numerical simulations demonstrate over 90% agreement with experimental data, confirming the method's reliability for complex hydrodynamic coupling analysis; (3) Under both wave conditions, central modules exhibit greater sensitivity to wave transmission with larger surge, sway, and pitch motions, while transitional modules show amplified yaw and pitch responses due to adjacent module interference; (4) Mooring lines connected to central modules bear higher tensions in both scenarios, achieving a safety factor of 1.86 under beam sea conditions (satisfying API specifications), with significantly enhanced safety margins under oblique waves. These findings provide valuable references for floating breakwater engineering applications in nearshore complex environments.
Yang et al. (Fri,) studied this question.