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PASSIVE ALLEVIATION OF MICRO-PRESSURE WAVES FROM TUNNEL PORTALS

โœ Scribed by T. Aoki; A.E. Vardy; J.M.B. Brown

Publisher
Elsevier Science
Year
1999
Tongue
English
Weight
460 KB
Volume
220
Category
Article
ISSN
0022-460X

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โœฆ Synopsis

When a high-speed train enters a tunnel, it generates a compression wave which propagates along the tunnel ahead of the train. A small proportion of the wave subsequently emerges from the exit portal of the tunnel as an impulsive wave. This so-called micro-pressure wave causes annoyance through low frequency noise and vibrations in the surrounding area. The objective of this paper is to determine the optimum dimensions of an expansion chamber at the tunnel exit portal for the purpose of reducing the micro-pressure wave. The effects of expansion chambers are investigated numerically and experimentally. Optimum proportions of a right-cylindrical chamber are found and a clear relationship is obtained between the total volume and the degree of attenuation of the micro-pressure wave.

๐Ÿ“œ SIMILAR VOLUMES

Reflections of Pressure Waves at Tunnel
Reflections of Pressure Waves at Tunnel Portals
โœ J.M.B. Brown; A.E. Vardy ๐Ÿ“‚ Article ๐Ÿ“… 1994 ๐Ÿ› Elsevier Science ๐ŸŒ English โš– 524 KB

Reflections of plane waves from the open ends (portals) of axisymmetric pipes and plane two-dimensional (2-D) channels are investigated analytically, numerically and experimentally. An analytical approach developed by Rudinger [1] for pressure decay at an axisymmetric, flanged portal is extended to