Assessment of Vortex Induced Vibrations on wind turbines
Dimitris Manolas, P. Chaviaropoulos, Vasilis A. Riziotis
Abstract
Abstract Modern wind turbines are prone to Vortex Induced Vibrations (VIV). In the present work, an engineering semi-empirical framework is proposed that assesses VIV aero-elastic instabilities of wind turbine configurations. The procedure employs engineering tools relying on airfoil polars. It uses the state-of-the-art aero-elastic tool hGAST along with the EUROCODE VIV framework for steel structures extended to wind turbine configurations. The aero-elastic tool provides the missing modal input data (i.e. modal frequencies, total structural plus aerodynamic modal damping and modeshapes) to evaluate the semi-analytical expressions of the displacement and load amplitudes. Numerical results for single- and two-bladed configurations of the NREL 5MW Reference Wind Turbine (RWT) during assembly are presented, assessing turbine loads under the most unfavourable VIV scenarios examined.