Print Email Facebook Twitter Unsteady aerodynamics and vortex shedding of a wind turbine blade Title Unsteady aerodynamics and vortex shedding of a wind turbine blade Author Iyer, Sowmya (TU Delft Aerospace Engineering) Contributor Ferreira, Carlos (mentor) Bertagnolio, Franck (graduation committee) Grinderslev, Christian (graduation committee) Yu, W. (graduation committee) Xu, G. (graduation committee) van Oudheusden, B.W. (graduation committee) Degree granting institution Delft University of Technology Corporate name Delft University of Technology Programme European Wind Energy Masters (EWEM) Date 2023-08-25 Abstract The thesis presents an analysis of unsteady vortex shedding and vortex induced vibrations (VIV) on wind turbine blades using a combination of Stereoscopic Particle Image Velocimetry (SPIV) and Computational Fluid Dynamics (CFD). A spanwise uniform blade with a symmetric NACA0021 airfoil section, 0.075 m chord, and 0.4 m span was tested experimentally for a static, plunging, and surging blade oscillating at 90 deg angle of attack, 5 Hz, and 2.5 Hz frequency, 1 chord oscillation amplitude. Equivalent CFD simulation cases were run to compare the results and validate the CFD setup, which was used to analyse additional cases of interest. The extent of the three-dimensional flow behaviour due to the tip vortex was described, along with determining the lock-in region for the two motions using additional simulations. The results indicated that the spanwise convection of the tip vortex and the transition to a ‘2D’ flow were only dependent on the blade aspect ratio and independent of the freestream wind speed, the type of motion, and the oscillation frequency. The lock-in region for the plunging and surging blades was presented, noting that all the surging cases were locked in, most likely due to the large oscillation amplitude. However, the surging cases had a positive aerodynamic damping and hence, VIV would not be excited for a freely vibrating blade. It is suggested as future work to test a flexible blade and study the onset and development of VIV. Subject Vortex induced vibrationsVortex Induced MotionFlow visualizationCFDwind tunnel experimentWind Turbine Bladelock-in rangeStrouhal number To reference this document use: http://resolver.tudelft.nl/uuid:105bcf3a-8c6d-4dfe-9165-5ba42d415788 Part of collection Student theses Document type master thesis Rights © 2023 Sowmya Iyer Files PDF MSc_Thesis_EWEM_Rotor_Des ... N_IYER.pdf 91.12 MB Close viewer /islandora/object/uuid:105bcf3a-8c6d-4dfe-9165-5ba42d415788/datastream/OBJ/view