The influence of reflections from the train body and the ground on the sound radiation from a railway rail
The influence of reflections from the train body and the ground on the sound radiation from a railway rail
Purpose: the vibration of the rails is a significant source of railway rolling noise, often forming the dominant component of noise in the important frequency region between 400 and 2000 Hz. The purpose of the paper is to investigate the influence of the ground profile and the presence of the train body on the sound radiation from the rail.
Design/methodology/approach: two-dimensional boundary element calculations are used, in which the rail vibration is the source. The ground profile and various different shapes of train body are introduced in the model and results are observed in terms of sound power and sound pressure. Comparisons are also made with vibro-acoustic measurements performed with and without a train present.
Findings: the sound radiated by the rail in the absence of the train body is strongly attenuated by shielding due to the ballast shoulder. When the train body is present, the sound from the vertical rail motion is reflected back down towards the track where it is partly absorbed by the ballast. Nevertheless, the sound pressure at the trackside is increased by typically 0-5 dB. For the lateral vibration of the rail the effects are much smaller. Once the sound power is known, the sound pressure with the train present can be approximated reasonably well with simple line source directivities.
Originality: numerical models used to predict the sound radiation from railway rails have generally neglected the influence of the ground profile and reflections from the underside of the train body on the sound power and directivity of the rail. These effects are studied in a systematic way including comparisons with measurements.
Rolling noise, Sound radiation, Railway track, boundary elements, Ground reflections, Directivity
Thompson, David
bca37fd3-d692-4779-b663-5916b01edae5
Zhao, Dong
68edf852-499c-451b-9f75-041af9dd96ed
Ntotsios, Evangelos
877c3350-0497-4471-aa97-c101df72e05e
Squicciarini, Giacomo
c1bdd1f6-a2e8-435c-a924-3e052d3d191e
Cierco, Ester
20120c7e-b3dc-4292-af5f-824e0c5c33b9
Jansen, Erwin
5a43b7a9-0534-4597-bb65-6c6fbb3b2231
Thompson, David
bca37fd3-d692-4779-b663-5916b01edae5
Zhao, Dong
68edf852-499c-451b-9f75-041af9dd96ed
Ntotsios, Evangelos
877c3350-0497-4471-aa97-c101df72e05e
Squicciarini, Giacomo
c1bdd1f6-a2e8-435c-a924-3e052d3d191e
Cierco, Ester
20120c7e-b3dc-4292-af5f-824e0c5c33b9
Jansen, Erwin
5a43b7a9-0534-4597-bb65-6c6fbb3b2231
Thompson, David, Zhao, Dong, Ntotsios, Evangelos, Squicciarini, Giacomo, Cierco, Ester and Jansen, Erwin
(2024)
The influence of reflections from the train body and the ground on the sound radiation from a railway rail.
Railway Sciences, 3 (1).
(doi:10.1108/RS-11-2023-0041).
Abstract
Purpose: the vibration of the rails is a significant source of railway rolling noise, often forming the dominant component of noise in the important frequency region between 400 and 2000 Hz. The purpose of the paper is to investigate the influence of the ground profile and the presence of the train body on the sound radiation from the rail.
Design/methodology/approach: two-dimensional boundary element calculations are used, in which the rail vibration is the source. The ground profile and various different shapes of train body are introduced in the model and results are observed in terms of sound power and sound pressure. Comparisons are also made with vibro-acoustic measurements performed with and without a train present.
Findings: the sound radiated by the rail in the absence of the train body is strongly attenuated by shielding due to the ballast shoulder. When the train body is present, the sound from the vertical rail motion is reflected back down towards the track where it is partly absorbed by the ballast. Nevertheless, the sound pressure at the trackside is increased by typically 0-5 dB. For the lateral vibration of the rail the effects are much smaller. Once the sound power is known, the sound pressure with the train present can be approximated reasonably well with simple line source directivities.
Originality: numerical models used to predict the sound radiation from railway rails have generally neglected the influence of the ground profile and reflections from the underside of the train body on the sound power and directivity of the rail. These effects are studied in a systematic way including comparisons with measurements.
Text
The influence of the train body and ground on the sound radiation from a railway rail_RS_final_2
- Accepted Manuscript
Text
10-1108_RS-11-2023-0041
- Version of Record
More information
Accepted/In Press date: 15 December 2023
e-pub ahead of print date: 2 January 2024
Keywords:
Rolling noise, Sound radiation, Railway track, boundary elements, Ground reflections, Directivity
Identifiers
Local EPrints ID: 485759
URI: http://eprints.soton.ac.uk/id/eprint/485759
ISSN: 2755-0907
PURE UUID: 4cc84fe5-e37f-4e86-83a4-e3b393442827
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Date deposited: 18 Dec 2023 20:35
Last modified: 27 Apr 2024 02:14
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Contributors
Author:
Dong Zhao
Author:
Ester Cierco
Author:
Erwin Jansen
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