Bennett, Jeffrey6; Bitsche, Robert5; Branner, Kim1; Kim, Taeseong1
1 Department of Wind Energy, Technical University of Denmark2 Wind Turbines, Department of Wind Energy, Technical University of Denmark3 Aeroelastic Design, Department of Wind Energy, Technical University of Denmark4 Southwest Research Institute5 Risø National Laboratory for Sustainable Energy, Technical University of Denmark6 Southwest Research Institute
In this paper a quick method for modeling composite wind turbine blades is developed for aeroelastic simulations and finite element analyses. The method reduces the time to model a wind turbine blade by automating the creation of a shell finite element model and running it through a cross-sectional analysis tool in order to obtain cross-sectional properties for the aeroelastic simulations. The method utilizes detailed user inputs of the structural layup and aerodynamic profile including ply thickness, orientation, material properties and airfoils to create the models. After the process is complete the user has two models of the same blade, one for performing a structural finite element model analysis and one for aeroelastic simulations. Here, the method is implemented and applied to reverse engineer a structural layup for the NREL 5MW reference blade. The model is verified by comparing natural frequencies to the reference blade. Further, the application to aeroelastic and structural evaluations is demonstrated. Aeroelastic analyses are performed, and predicted fatigue loads are presented. Extreme loads from the aeroelastic simulations are extracted and applied onto the blade for a structural evaluation of the blade strength. Results show that the structural properties and natural frequencies of the developed 5MW blade match well with the reference blade, however the structural analysis found excessive strain at 16% span in the spare caps that would cause the blade to fail.
Proceedings of Asme Turbo Expo 2014: Turbine Technical Conference and Exposition, 2014