|The dynamics of an offshore wind turbine in parked conditions: a comparison between simulations and measurements|Shirzadeh, R.; Weijtjens, W.; Guillaume, P.; Devriendt, C. (2015). The dynamics of an offshore wind turbine in parked conditions: a comparison between simulations and measurements. Wind Energ. 18(10): 1685-1702. dx.doi.org/10.1002/we.1781
In: Wind Energy. Wiley: Chichester. ISSN 1095-4244, more
offshore wind turbine; simulations; measurements; parked conditions;dynamics; damping
Offshore wind turbines are complex structures, and their dynamics can vary significantly because of changes in operating conditions, e.g., rotor-speed, pitch angle or changes in the ambient conditions, e.g., wind speed, wave height or wave period. Especially in parked conditions, with reduced aerodynamic damping forces, the response due to wave actions with wave frequencies close to the first structural resonance frequencies can be high. Therefore, this paper will present numerical simulations using the HAWC2 code to study an offshore wind turbine in parked conditions. The model has been created according to best practice and current standards based on the design of an existing Vestas V90 offshore wind turbine on a monopile foundation in the Belgian North Sea. The damping value of the model's first fore-aft mode has been tuned on the basis of measurements obtained from a long-term ambient monitoring campaign on the same wind turbine. Using the updated model of the offshore wind turbine, the paper will present some of the effects of the different design parameters and the different ambient conditions on the dynamics of an offshore wind turbine. The results from the simulations will be compared with the processed data obtained from the real measurements. The accuracy of the model will be discussed in terms of resonance frequencies, mode shapes, damping value and acceleration levels, and the limitations of the simulations in modeling of an offshore wind turbine will be addressed. Copyright (c) 2014 John Wiley & Sons, Ltd.