TITLE:
Characteristics of Unsteady Boundary Layer Induced by the Compression Wave Propagating in a Tunnel
AUTHORS:
Toshiyuki Tanaka, Toshiyuki Aoki
KEYWORDS:
Transition; Unsteady Boundary Layer; Compression Wave; Laser Differential Interferometry
JOURNAL NAME:
Open Journal of Fluid Dynamics,
Vol.2 No.4A,
January
2,
2013
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.