Investigation on the dynamics of shared-mooring floating wind turbines: assessing the impact of spacing and wake effect

The rapid expansion of offshore wind energy has intensified the demand for cost-effective deep-water solutions, highlighting the significant economic potential of shared-mooring systems. However, the coupled dynamics and wake interactions of dual shared-moored floating wind turbines, strongly influenced by turbine spacing, remain insufficiently understood. This study investigates two shared-mooring floating wind turbines under different spacings (5D–10D, where D denotes rotor diameter), considering wake effects through an improved equivalent coefficient method. Results show that the shared-mooring system achieves cost savings of up to 26.93% at 5D compared with individual mooring configurations, while wake-induced power losses decrease from 60.48% at 5D to 35.97% at 10D. Crucially, free decay analyses reveal that while synchronous natural periods remain stable, the anti-phase surge period is highly spacing-dependent due to variations in the shared line's restoring stiffness. Under aligned environmental loads, the system exhibits strong response asymmetry. Driven by slackened leeward mooring constraints, the downstream turbine experiences larger displacement. Furthermore, wake-induced asymmetric loading not only reduces the mean offset of the downstream turbine but also alters the upstream turbine's dynamics through the mechanical feedback of the shared line. These findings provide critical guidance and valuable insights for designing and optimizing shared-mooring floating wind farms.