Characteristics of Unsteady Boundary Layer Induced by the Compression Wave Propagating in a Tunnel

Toshiyuki Tanaka; Toshiyuki Aoki

doi:10.4236/ojfd.2012.24A030

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Open Journal of Fluid Dynamics > Vol.2 No.4A, December 2012

Characteristics of Unsteady Boundary Layer Induced by the Compression Wave Propagating in a Tunnel ()

Department of Energy and Environmental Engineering, Graduate School of Engineering Sciences, Kyushu University, Fukuoka, Japan.

DOI: 10.4236/ojfd.2012.24A030 PDF HTML 4,982 Downloads 7,205 Views

Abstract

A compression wave is generated ahead of a high-speed train, while entering a tunnel. This compression wave propa- gates to the tunnel exit and spouts out as a micro pressure wave, causing an exploding sound. In order to estimate the magnitude correctly, the mechanism of the attenuation and distortion of a compression wave propagating along a tunnel must be understood and experimental information on these phenomena is required. An experimental and numerical in- vestigation is carried out to clarify the mechanism of the propagating compression wave in a tube. The final objective of our study is to understand the mechanism of the attenuation and distortion of propagating compression waves in a tun- nel. In the present paper, experimental investigations are carried out on the transition of the unsteady boundary layer induced by a propagating compression wave in a model tunnel by means of a developed laser differential interferometry technique.

Keywords

Transition; Unsteady Boundary Layer; Compression Wave; Laser Differential Interferometry

Share and Cite:

T. Tanaka and T. Aoki, "Characteristics of Unsteady Boundary Layer Induced by the Compression Wave Propagating in a Tunnel," Open Journal of Fluid Dynamics, Vol. 2 No. 4A, 2012, pp. 257-263. doi: 10.4236/ojfd.2012.24A030.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	S. Ozawa, T. Maeda, T. Matsumura and K. Uchida, “Countermeasures to reduce micro-pressure waves radiating from exits of Shin-kansen tunnels,” Proceedings of 7th International Symposium on Aero-Dynamics and Ventilation of Vehicle Tunnel, Elsevier Science Publishers Ltd., London, 1991, pp. 253-266.
[2]	H. Kashimura, T. Yasunobu, T. Aoki and K. Matsuo, “Emission of a Propagating Compression Wave from an Open End of a Tube,” JSME International Journal Series B, Vol. 39, No. 3, 1995, pp. 475-481.
[3]	K. Matsuo, T. Aoki, H. Kashimura, M. Kawaguchi and M. Takeuchi, “Attenuation of Compression Waves in a High-Speed Railway Tunnel Simulator,” Proceedings of 7th International on Aero-Dynamics and Ventilation of Vehicle Tunnel, Elsevier Science Publishers Ltd., London, 1991, pp. 239-253.
[4]	T. Fukuda, S. Ozawa, M. Iida, T. Takasaki and Y. Wakabayashi, “Distortion of the Compression Wave Propagating Through a Very Long Tunnel with Slab Tracks,” JSME International Journal Series B, Vol. 71, No. 709, 2005, pp. 36-43.
[5]	S. Nakao, “The Propagating Characteristic of Weak Pressure Wave in Long Tube,” Doctoral Dissertation, Kyushu University, Fukuoka, 2000.
[6]	R. A. Hartunian, “Boundary-Layer Transition and Heat Transfer in Shock Tubes,” Journal of the Aerospace Science, Vol. 27, No. 8, 1960, p. 587.