Hydrodynamic modeling effect analysis of a fully submerged tension leg concept integrating the DTU 10 MW offshore wind turbine

Efficient and accurate hydrodynamic load estimation is important for the dynamic response analyses of large-scale offshore wind turbines to achieve a reliable and cost-effective structural design. In this study, the hydrodynamic modeling effects based on a fully submerged tension leg platform (FSTLP) integrating the DTU 10 MW wind turbine are assessed. The linear potential flow theory combined with viscous drag force and the Morison's equation with added mass coefficients tuned by two different methods are investigated to assess their feasibility. The numerical simulations using different hydrodynamic models are performed and the results are validated by a series of hydrodynamic model tests. The dynamic motions and the structure forces of FSTLPWTs are analyzed in a range of wave-only and joint wind-wave conditions considering varying water depth. It shows that reliable predictions of the dynamic responses can be provided by the potential flow model with viscous drag force. Results obtained from Morison's equation with properly tuned added mass coefficients can match well with those provided by the potential flow model. The correct added mass coefficients are not necessarily obtained from the potential flow solutions. It is also found that the relative dominance of potential and viscous damping varies in different modes and can be affected by water depth.

Automated summary

Efficient and accurate hydrodynamic load estimation is important for the dynamic response analyses of large-scale offshore wind turbines. This study assesses the hydrodynamic modeling effects of a fully submerged tension leg platform (FSTLP) integrating a 10 MW wind turbine. The results show that the potential flow model with viscous drag force can provide reliable predictions of the dynamic responses.