Simple and accurate analysis of MPWs: Near-field and far-field

Alan E. Vardy (Lead / Corresponding author)

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

A simple and efficient method of simulating wave propagation in radially-symmetric environments is used to extend the practical scope of assessing micro-pressure wave (MPW) radiation from railway tunnel portals. The method utilises a recently developed solution technique based on a one-dimensional Method of Characteristics (MOC) for spherical wave propagation. Close similarities exist with corresponding MOC methods used to simulate uniaxial wave propagation inside tunnels and this enables a simple, continuous coupling to be made between the internal and external flow domains. Integral coupling has numerical advantages, but its primary benefit is physical realism, enabling account to be taken of behaviour that is neglected in many simpler analyses. The coupled analysis is used to illustrate strong differences between outcomes resulting from the arrival of low-frequency and high frequency wavefronts at a tunnel portal. The most useful purpose of the new coupled methodology is expected to lie in the efficiency with which multiple simulations can be undertaken. This is because it is far less resource-intensive than 3-D methods of allowing for coupling. Another, less general benefit, is a demonstrated ability to use MOC to simulate train-entry, wave-propagation and MPW radiation in a single unified manner, albeit only in a strictly limited range of cases that will rarely exist in older tunnels.

Original languageEnglish
Title of host publicationProceedings of the 18th International Symposium on Aerodynamics, Ventilation and Fire in Tunnels (ISAVFT 2019)
PublisherBHR Group Limited
Pages163-177
Number of pages15
ISBN (Print)9781713813583
Publication statusPublished - Jul 2020
Event18th International Symposium on Aerodynamics, Ventilation and Fire in Tunnels, ISAVFT 2019 - Athens, Greece
Duration: 25 Sep 201927 Sep 2019

Conference

Conference18th International Symposium on Aerodynamics, Ventilation and Fire in Tunnels, ISAVFT 2019
CountryGreece
CityAthens
Period25/09/1927/09/19

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  • Cite this

    Vardy, A. E. (2020). Simple and accurate analysis of MPWs: Near-field and far-field. In Proceedings of the 18th International Symposium on Aerodynamics, Ventilation and Fire in Tunnels (ISAVFT 2019) (pp. 163-177). BHR Group Limited.