Acoustic Noise Measurement Downstream of an Oscillating Wind Turbine Blade Section

Document Type : Regular Article

Authors

Department of Engineering, Tehran Science and Research Branch, Islamic Azad University, Poonak, Tehran, 14155-4933, Iran

Abstract

Acoustic measurements were performed using microphone downstream of a 2-D wind turbine blade section in wind tunnel. The experiments have been carried out in both static and oscillatory pitching cases. The latter is usually experienced by the blades in actual circumstances. The microphone was 1.5 chords downstream of the airfoil and the measurements were conducted at three transverse positions, i.e. behind the trailing edge, midway between the trailing edge and the ground and very close to the ground. A CFD simulation of the flowfield has also been conducted using Fluent to correlate the acoustic behavior to the phenomena observed in the flowfield around the blade. The results show that the acoustic noise heard by a listener located on the ground is higher and stronger than that positioned downstream of the trailing edge, showing the ground effect on acoustic noise reverberation. The aerodynamic noise heard by the listener, changes from a treble to bass sound as the angle of attack increases. Beyond stall, the flow is dominated by the vortices shed into wake and the acoustic noises would be at very low frequencies which would result in a bass sound accompanied by structural vibration. In high angle of attack range, such noises can hardly be heard by a normal person but have a very destructive role on blade structure.

Keywords

Main Subjects


Arnold, B., Lutz, T. H., & Krämer, E. (2018). Design of a boundary-layer suction system for turbulent trailing-edge noise reduction of wind turbines. Renewable Energy, 123, 249-262. https://doi.org/10.1016/j.renene.2018.02.050
Bak, C., Fuglsang, P., Johansen, J., & Antoniou, I. (2000). Wind tunnel tests of the NACA 63-415 and a modified NACA 63-415 Airfoil, Risø National Laboratory, 1193(EN), Denmark, ISBN 87-550-2716-4. https://doi.org/10.2514/6.2017-4626
Bertagnolio, F., Madsen, H. A., Fischer, A., & Bak, C. (2016, April 10-15). Validation of an aero-acoustic wind turbine noise model using advanced noise source measurements of a 500 kW turbine. International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, Hawaii, Honolulu. https://hal.science/hal-01891317
Bhargava, V., & Samala, R. (2019). Acoustic emissions from wind turbine blades. Journal of Aerospace Technology Management, 11, 1458-1467. https://doi.org/10.5028/jatm.v11.1071
Cao, H., Zhang, M., Zhang, Y., & Zhou, T. (2021). A general model for trailing edge serrations simulation on wind turbine airfoils. Theoretical and Applied Mechanics Letters, 11(4), 100284. https://doi.org/10.1016/j.taml.2021.100284
Dai, Y., & Li, B. (2019). A numerical study of the acoustic radiation characteristics of the aerodynamic noise in the near-wake region of a wind turbine. Results in Physics, 15, 257-269. https://doi.org/10.1016/j.rinp.2019.102782
Davari, A. R. (2017). Wake structure and similar behavior of wake profiles downstream of a plunging airfoil. Chinese Journal of Aeronautics, 30(4), 1281–1293. https://doi.org/10.1016/j.cja.2017.05.007
Deshmukh, S., Bhattacharya, S., Akshoy, A., & Paul, R. (2019). Wind turbine noise and its mitigation techniques: A review. Energy Procedia, 160, 633-640. https://doi.org/10.1016/j.egypro.2019.02.215
Dijkstra, P. W. (2015). Rotor noise and aero-acoustic optimization of wind turbine airfoils. [MSc Thesis, Delft University of Technology]. http://dx.doi.org.proxy.lib.utk.edu:90/10.1007/978-3-540-71343-2
Fuglsang, P., & Madsen, H. A. (1998). Wind turbine design with numerical optimization and a semi-empirical noise prediction model. Wind Engineering, 22(1), 31–41. https://www.jstor.org/stable/43749913
Li, J., Liu, R., Yuan, P., Pei, Y., Cao, R., & Wang, G. (2020). Numerical simulation and application of noise for high-power wind turbines with double blades based on large eddy simulation model, Renewable Energy, 146(1), 1682-1690. 10.1016/j.renene.2017.10.058
Maizi, M., Mohamed, M. H., Dizene, R., & Mihoubi, M. C. (2018). Noise reduction of a horizontal wind turbine using different blade shapes. Renewable Energy, 117, 242-256. https://doi.org/10.1016/j.renene.2017.10.058
Merino-Martínez, R., Pieren, R. & Schäffer, B. (2021). Holistic approach to wind turbine noise: From blade trailing-edge modifications to annoyance estimation, Renewable and Sustainable Energy Reviews, 148(2), 111285. https://doi.org/10.2514/1.C035655
Su, J., Lei, H., Zhou, D., Han, Z., Bao, Y., Zhu, H., & Zhou, L. (2019). Aerodynamic noise assessment for a vertical axis wind turbine using improved delayed detached eddy simulation, Renewable Energy. 141, 559-569. https://doi.org/10.1016/j.renene.2019.04.038
Tonin, R. (2012). Sources of wind turbine noise and sound propagation. Acoustics Australia, 40(1), 3376-387. https://doi.org/10.1007/s40857-017-0098-3
Volkmer, K, Kaufmann, N., Carolus, T. H. (2021). Mitigation of the aerodynamic noise of small axial wind turbines-methods and experimental validation. Journal of Sound and Vibration, 500, 116027, 468-480. https://doi.org/10.1016/j.jsv.2021.116027
Wagner, S. J., Bareiss, R., & Guidati, G. (1996). Wind turbine noise, Springer. https://doi.org/10.1007/978-3-642-88710-9
Wasala, S. H., Storey, R. C., Norris, S. E. & Cater, J. E. (2015). Aeroacoustic noise prediction for wind turbines using Large Eddy Simulation. Journal of Wind Engineering and Industrial Aerodynamics, 145, 17-29. https://doi.org/10.1016/j.jweia.2015.05.011