**4. Conclusions**

This study used NREL developed FAST and Turbsim software to generate the environmental loads, which were based on the regulation code IEC 61400-1 and 3. ANSYS-Fluent and ANSYS-Mechanical modules were also used to perform the fluid–structure interaction between OWT and TLDs. The convergence tests and numerical simulation validation were made to confirm the accuracy of the simulation tools used in the study. Extensive simulation cases were made, and the following conclusion were found.


by 44% and 24% in fore-aft and side-to-side displacements, respectively. Similar damping e ffects of TLD can be found in DLC 6.2 load conditions.


**Author Contributions:** Conceptualization, B.-F.C.; methodology, B.-F.C. and S.-H.C.; software, S.-H.C.; validation, S.-H.C. and P.-H.Y.; writing—original draft preparation, S.-H.C. and B.-F.C.; writing—review and editing, B.-F.C. and P.-H.Y.; visualization, P.-H.Y.; supervision, B.-F.C. and P.-H.Y.; project administration, B.-F.C.; funding acquisition, B.-F.C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study is partially supported by a gran<sup>t</sup> of Ministry of Science and Technology of ROC under a grant-number MOST-102-2221-E-110-039-MY3.

**Conflicts of Interest:** The authors declare no conflict of interest.
