Abstract
Cyber-physical test and numerical simulation results for two shared mooring farms, consisting of 2 and 9 floating wind turbines, are analysed using a modal basis. Decay tests show a single dominant modal response. In irregular wave tests, comparisons with numerical simulations are limited to 5-9 modes that contribute significantly to line tension. These modes could reproduce the selected line tension standard deviation within 15%. The power spectral density of shared line tension and modal responses in the wave-frequency range exhibits a distinct comb-like frequency response associated with modal excitation from first-order wave loads. To meet the real-time computational requirement of cyber-physical tests, the mooring line model used during the test was a quasi-static model. Numerical comparisons are made between simulations with quasi-static and dynamic mooring line models for the tested shared-mooring farms to assess the impact of this simplification. In irregular wave tests, the quasi-static mooring line model overestimated the horizontal translational motion standard deviation by up to 20% (0.29 m full scale). Although direct application of the quasi-static mooring model underestimated the shared line tension standard deviation by up to approximately 80%, line tensions can be accurately reconstructed during post-processing.