Computation of Modal Aerodynamic Damping Using CFD

Abstract

This work focuses on the numerical evaluation of aerodynamic damping for a wind turbine rotor. A finite beam element code is used to describe the structure. Two types of aerodynamic models are compared. Firstly, two engineering semi-empirical dynamic stall models implemented in the structural code for modelling the aerodynamic forces are applied. Secondly, a Navier-Stokes flow solver has been coupled to the structural model. Test cases involving a two-bladed wind turbine rotor are computed. The aerodynamic damping is determined for the two first eigenmodes of the structure. A comparison study of the results highlights the discrepancies between the different models.