Validation of a 20m wind turbine blade model

Abstract

In the projects Smartblades and Smartblades 2 a full-scale 20m rotor blade for the NREL CART3 wind turbine was designed, built and tested. The rotor blade was intended to have a strong bending-torsion coupling. By means of the experiments, the proof for the technology in question was supposed to be provided. The experimental work was accompanied by simulations. The aim of the paper is to describe and publish a reference finite element model for the 20 m rotor blade. The validation procedure is presented as well as the modelling strategy and the limitations of the model. The finite element model is created using quadratic finite shell elements and quadratic solid elements. Different data sets were used for the validation. First the data of static test bench experiments was used. The validation comprises the comparison of global displacement and local strain measurements for various flap and edge bending tests as well as for torsion unit loading tests. Second the blades' eigenfrequencies and eigenvectors in a clamped and free-free scenario were used for validation. Third the mass distribution of the finite element and real blade was investigated. The paper provides the evaluated experimental data and all analysed scenarios as well as the corresponding finite element model in Abaqus, Ansys and Nastran and format as reference dataset.