FE-based Modeling of Gear-excited Vibrations and Vibroacoustic Transfer in Wind Turbine Drivetrains
* Presenting author
The control of noise emission from wind turbines, especially tonalities in the far-field noise spectrum, has become an issue of growing attention and strict regulation. The tonalities can be traced back to mechanical sources within the drivetrain, e.g. gearbox or generator. We present a hybrid approach for gear modeling that combines a detailed finite element analysis of meshing configurations with analytical models for the transient dynamics of helical gears. A comparison with results from the literature shows excellent agreement for spur gears. We also present numerical results for helical gears, which so far have not been extensively studied. The results from the FE analyses are then used to simulate the transient dynamics of the gear system with analytical models. This modelling is applied to the analysis of a wind turbine gearbox, and the resulting frequency spectra are compared to acoustic field measurements. The peak frequencies match exactly over a broadband spectrum of several KHz, where the amplitudes match the experimental measurements qualitatively very well. The excitation model shall be applied in the simulative investigation of the propagation of structural sound through the drivetrain and the radiation of air-borne sound from major vibrating parts of the wind turbine.