This paper describes the process adopted to set up a FAST model to produce relevant design load cases (DLCs) for the Levenmouth (Samsung Heavy Industries - S7.0-171) demonstration foreshore wind turbine owned by the Offshore Renewable Energy Catapult (ORE Catapult). The paper does not take into account hydrodynamic forces.
Existing literature has carried out FAST studies predominantly using reference turbines (e.g. NREL-5MW, DTU-10MW) instead of real prototype or commercial turbines. This paper presents the results for the Levenmouth wind turbine, a real, operating demonstration wind turbine. The paper explores and simulates the critical loads for the turbine, which will be very valuable validation case for industrial and academic use. Moreover, the Levenmouth wind turbine exhibits a new generation of extremely flexible blades that conflict with the previous approaches used by most common aero-elastic codes and makes this simulation a challenge.
The study is divided into three steps. It starts with building the model and fine-tuning it until it matches the natural frequencies of the blades and tower. The second step encompasses the comparison of the commissioning results with the relevant NREL FAST simulations to match the dynamic behaviour of the turbine. The final step comprises a load comparison for the interface between the tower and transition piece, in order to validate the new aero-elastic model with the commissioning loads.
The results of the study show 98% agreement in the natural frequencies and dynamic performance, and a 78% agreement in the loads between the aero-servo-elastic model and the certification results.
The present study is framed into an engineering doctorate project and a more comprehensive turbine virtualisation project. We anticipate that our work to be the initial point for more sophisticated aero-elastic models adapted to the unique properties of the Levenmouth demonstration wind turbine.