Abstract
The purpose of this study is to understand the aerodynamic noise source distribution around a rotating fan blade by measuring the noise signal and velocity field around the blade. The local noise-level distribution over the fan blade is measured by microphone arrays, and the flow field is visualized by smoke and phase-averaged PIV measurement. The noise source distribution is examined by cross-correlation analysis between noise signal and velocity fluctuation. It is found that the noise source is located near the rotating fan blade, especially around leading and trailing edges. The separation and reattachment of flow are observed near the leading edge, and the tip vortices and vortex shedding are found near the trailing edge. The cross-correlation distribution of the noise signal and the radial velocity fluctuation shows large magnitude in the correlated regions, which indicates the noise generation by the formation of vortex structure around the blade.
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Atsushi Nashimoto: He graduated from Graduate School of Niigata University and received a degree of Dr. Eng. in 2007. He has been working at Mitsuba Corporation since 1972, and now he is a senior researcher in the Technical Development Department. His current research interests are flow visualization and measurement of noise from rotating machinery.
Nobuyuki Fujisawa: After graduating from Graduate School of Tohoku University (D.E. 1983), he joined Gunma University in 1983 and worked as an associate professor in 1991. Since 1997, he has been a professor of Niigata University and is currently a director of Visualization Research Center at Niigata University. His current research interests are visualization and non-intrusive measurement of velocity and temperature field of complex flow and the flow accelerated corrosion and erosion problems of highly aged nuclear power plant.
Takeshi Yoda: After graduating from Nihon University in 1979, he joined Mitsuba Corporation in 1981. From 1981 to 1990, he engaged on development of motorcycle generator in the Design Section, from 1990 to 1997, CAE/noise vibration analysis in the Research Department, and since 1998, he has been working on CAE analysis in the Technical Development Department. Now he is the Department Manager.
Tomonori Nakano: After graduating from Graduate School of Niigata University (D.E. 2006), he joined Mitsuba Corporation in 2006 and since then, has been working on various kinds of flow visualization experiments in the Technical Development Department.
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Nashimoto, A., Fujisawa, N., Nakano, T. et al. Visualization of aerodynamic noise source around a rotating fan blade. J Vis 11, 365–373 (2008). https://doi.org/10.1007/BF03182205
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DOI: https://doi.org/10.1007/BF03182205