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Determination of Aerodynamic Sound Sources on Periodicity Noise Generated from a Micro Wind Turbine

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http://www.scirp.org/journal/PaperInformation.aspx?PaperID=52854#.VKs-ecnQrzE

To discuss the relationship between the periodicity noise and the aerodynamic noise source of a wind turbine, the characteristics of the actual wind turbine were measured by a wind tunnel; moreover, the flow around the impeller immersed in the uniform flow was solved by numerical simulation. In the observed wind turbine, when the mainstream velocity was 7.4 m/s or more, the power coefficient reached maximum at tip speed ratio 8. When the mainstream velocity increased in the driving condition of the maximum power point, the aerodynamic noise increased due to the periodicity noise in the vicinity of 1000 Hz and the broadband noise in the high-frequency domain. The noise sources were concentrated at the leading edge and trailing edge on the suction surface side. We experimentally indicated that the pressure fluctuation of the leading edge was the source of the periodicity noise.
Cite this paper
Sasaki, S. , Sakada, R. and Suzuki, K. (2014) Determination of Aerodynamic Sound Sources on Periodicity Noise Generated from a Micro Wind Turbine. Open Journal of Fluid Dynamics, 4, 440-446. doi: 10.4236/ojfd.2014.45034. 
 

[1] Nii, Y., Gotanda, T., Matsumiya, H., Yamane, T. and Kawamura, S. (1992) Impulsive Low-Frequency Noise Generation by a 15 m Diameter Horizontal Axis Wind Turbine Generator with Downwind Configuration. Journal of the Acoustical Society of Japan, 13, 259-265.
http://dx.doi.org/10.1250/ast.13.259
[2] Sasaki, S., Suzuki, K. and Sakada, R. (2014) Study of Output Characteristics and Broadband Noise of a Micro Propeller Wind Turbine. Reports of Graduate School of Engineering, Nagasaki University, 44, 1-6.
[3] Sasaki, S. and Sakada, R. (2014) Study of Aerodynamic Noise Source of Periodical Noise Generated from a Micro Wind Turbine. Reports of Graduate School of Engineering, Nagasaki University, 44, 1-6.
[4] Amiet, R.K. (1976) Noise Due to Turbulent Flow past a Trailing Edge. Journal of Sound and Vibration, 47, 387-393.
http://dx.doi.org/10.1016/0022-460x(76)90948-2
[5] Howe, M.S. (1978) A Review of the Theory of Trailing-Edge Noise. Journal of Sound and Vibration, 61, 437-465.
http://dx.doi.org/10.1016/0022-460x(78)90391-7
[6] Roger, M. and Moreau, S. (2005) Back-Scattering Correction and Further Extensions of Amiet’s Trailing Edge Noise Model. Part I: Theory, Journal of Sound and Vibration, 286, 477-506.
http://dx.doi.org/10.1016/j.jsv.2004.10.054
[7] Moreau, S. and Roger, M. (2009) Back-Scattering Correction and Further Extensions of Amiet’s Trailing Edge Noise Model. Part II: Application, Journal of Sound and Vibration, 323, 397-425.
http://dx.doi.org/10.1016/j.jsv.2008.11.051              eww150105lx
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