ABSTRACT This study deals with the aerodynamic sound, especially the Aeolian tone. One of the problems with the aerodynamic sound, noise reduction along a railway line is significant engineering issue for further speed-up of a high-speed train. In particular, a pantograph is one of the main aerodynamic noise sources of a high-speed train. As one of the methods for the aerodynamic noise reduction, this study proposes the tapered cylinder by a pantograph. In this paper, the aerodynamic sound and the wake flow of the combinational inclined circular cylinder and tapered cylinder are experimentally and numerically investigated in knuckle upstream and knuckle downstream. Also, we suggest that the surface of grooves such as wood grain interacts with the aerodynamic sound generated from the model. Here, it is considered that the comparison of aerodynamic sound between the model with grooves and without grooves. Consequently, reduction of the maximum aerodynamic sound is possible for the tapered cylinder in the case of knuckle downstream. Furthermore, the noise reduction method is effective that the model surface with grooves such as wood grain.
Cite this paper
K. Sato, R. Machida and T. Aoki, "Aerodynamic Sound and Flow Field Generated from Combinational Inclined Tapered Cylinder," Open Journal of Fluid Dynamics, Vol. 2 No. 4, 2012, pp. 222-227. doi: 10.4236/ojfd.2012.24A025.
 T. Sueki, M. Ikeda and T. Takaishi, “The Aerodynamic Noise Reduction by Porous Materials and Application to a Current Collector,” RTRI Report, Vol. 22, No. 5, 2008, pp. 26-31.
 Y. Ijichi, T. Odo, N. Kondoh and T. Aoki, “Sound Characteristic of Aerodynamic Noise Generated from Pantograph on a High-Speed Train,” Journal of JSME, Vol. 61, No. 85-2, 2008, pp. 19-20.
 M. Ikeda and T. Mitsumoji, “Method to Evaluate Structure of Low-Frequency Aerodynamic Noise Source Generated by Shinkansen Pantograph,” RTRI Report, Vol. 21, No. 12, 2007, pp. 47-52.
 K. Shibata, M. Hirai, T. Hariyama and Y. Sasaki, “Development of Low Noise Pantograph Adopted to the Superexpress Hayate,” Mitsubishi Heavy Industries Technical Review, Vol. 40, No. 3, 2003, pp. 154-157.
 K. Saito, H. Fujita and Y. Suzuki, “Experimental Study of the Characteristics of the Aeolian Tone and the Wake structures Generated from Tapered Circular Cylinders,” Journal of JSME Fluid Engineering Conference 2010, Vol. 1006, No. 88, 2010, pp. 271-272.
 J. Fukutomi, Y. Nakase and M. Takikawa, “Vortex Wake from Tapered and Stepped Circular Cylinders in a Uniform Flow,” Journal of JSME, Vol. 59, No. 92, 1993, pp. 684-690.
 T. Tsuchida, H. Hayashi, Y. Kodama, T. Fukano and S. Sasaki, “Relationship between Aeolian Tone and Wake of Inclined Tapered Cylinder,” Journal of JSME Environment Engineering Symposium 2006, Vol. 112, No. 16, 2006, pp. 65-68.
 Y. Haramoto, K. Matsuzaki, M. Munekata and H. Ohba, “An Experiment and Numerical Simulation of Aerodynamic Sound Generated from Inclined Circular Cylinder,” Journal of the Acoustical Society of Japan, Vol. 301, No. 58, 2002, pp. 282-288.