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

Toshiyuki Tanaka, Toshiyuki Aoki

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

DOI: 10.4236/ojfd.2012.24A030                

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

Conflicts of Interest

The authors declare no conflicts of interest.

References

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