Tonal effects in the noise radiation from wind turbines can be traced back to mechanical sources within the drivetrain. A hybrid analytical-numerical model for the gear transmission error is used to generate the vibrational source for a large-scale vibroacoustic FE model of a wind turbine drivetrain, and a case study of transfer path analysis is presented.
A new efficient method for the simulation of sound radiation from large vibrating structures with the Finite Element Method (FEM) is proposed. The acoustic radiation from the major radiating panels is simulated separately for each panel, using customized fluid domains that are weakly coupled to the vibrating structure. Thereby, a significant reduction of the model order is achieved, maintaining at the same time a high reliability of results for practical application. The pressure levels at arbitrary far-field microphone positions can be efficiently computed from the Equivalent Radiated Power functions that characterize the structural vibrations of the radiating panels.
This paper proposes an efficient hybrid analytical-computational approach for the simulation of mechanical vibrations and sound radiation in wind turbine drive trains.The computational procedure encompasses the detailed modeling of vibrational sources and structural sound paths as well as the major panels of airborne noise radiation. The angle-varying mesh stiffness is obtained from a series of quasi-static finite element simulations. A novel procedure is proposed to obtain the time-varying mesh stiffness at fluctuating speed. The varying mesh stiffness is introduced as a parametric excitation in an analytical gear model, and the Fourier-transformed results are used as vibrational sources in a finite-element-based harmonic response analysis of the drive train. The present paper focuses on the modeling of gear contact and gearbox vibrations. The models and procedures are outlined, and computational results are compared to physical measurements on a 2.5 MW wind turbine. The results are in good qualitative agreement at tonal frequencies. This is particularly the case at fluctuating speed, where both the simulation and the measurement show the characteristic effect of frequency modulation. The computational procedure has been expanded to the whole drive train and is effectively applied in the conception and evaluation of design measures for the reduction of tonal amplitudes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.