Effect of Ambient Air Temperature on the Compression Wave Propagating along a Railway Tunnel
The parameters of the compression wave propagating in a railway tunnel are significantly influenced by the large ambient air temperature variation throughout the year. High-speed train entering a railway tunnel produces a wave of finite amplitude to propagate at sonic speed. The wave attenuates whil...
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| Format: | Article |
| Language: | English |
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Isfahan University of Technology
2023-03-01
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| Series: | Journal of Applied Fluid Mechanics |
| Subjects: | |
| Online Access: | https://www.jafmonline.net/article_2189_cef01b5d3eefab4bb8f1f9ad955c963a.pdf |
| _version_ | 1811159887549300736 |
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| author | R. S. Iyer D. H. Kim H. D. Kim |
| author_facet | R. S. Iyer D. H. Kim H. D. Kim |
| author_sort | R. S. Iyer |
| collection | DOAJ |
| description | The parameters of the compression wave propagating in a railway tunnel are significantly influenced by the large ambient air temperature variation throughout the year. High-speed train entering a railway tunnel produces a wave of finite amplitude to propagate at sonic speed. The wave attenuates while propagation through viscous dissipation and inertial forces nonlinearly steepen the wave. As a result of the dependence of sound speed on air temperature, the wave characteristics are altered with changing temperature. Therefore, it is crucial to comprehend the impact of ambient air temperature on the properties of the compression wave in order to construct an aero-acoustically ideal railway tunnel system. The method of characteristics (MOC) has been used to solve Euler equations with steady and unsteady friction parameters in the current study. According to the findings, wave attenuation ratio is reducing along the tunnel length, and gradient is rising as train speed increases. The case study illustrates the key distance within a tunnel where the steepening ratio is at its highest point. This critical tunnel length is estimated to be 65 times the tunnel hydraulic diameter (300 km/h) for a particular air temperature (T = 323 K), and it decreases by 15% for a 70 K reduction (323K to 253K) in temperature. Similarly, the critical length falls by 40% for greater train speeds (500 km/h). |
| first_indexed | 2024-04-10T05:48:18Z |
| format | Article |
| id | doaj.art-2340fd4ae1a04d52b41bff1090c5b5f1 |
| institution | Directory Open Access Journal |
| issn | 1735-3572 1735-3645 |
| language | English |
| last_indexed | 2024-04-10T05:48:18Z |
| publishDate | 2023-03-01 |
| publisher | Isfahan University of Technology |
| record_format | Article |
| series | Journal of Applied Fluid Mechanics |
| spelling | doaj.art-2340fd4ae1a04d52b41bff1090c5b5f12023-03-05T06:16:39ZengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35721735-36452023-03-0116590591910.47176/jafm.16.05.14582189Effect of Ambient Air Temperature on the Compression Wave Propagating along a Railway TunnelR. S. Iyer0D. H. Kim1H. D. Kim2Department of Mechanical Engineering, Andong National University, Andong, Korea RepublicHypertube Express (HTX) Research Team, Korea Railroad Research Institute, Gyeonggi, Korea RepublicDepartment of Mechanical Engineering, Andong National University, Andong, Korea RepublicThe parameters of the compression wave propagating in a railway tunnel are significantly influenced by the large ambient air temperature variation throughout the year. High-speed train entering a railway tunnel produces a wave of finite amplitude to propagate at sonic speed. The wave attenuates while propagation through viscous dissipation and inertial forces nonlinearly steepen the wave. As a result of the dependence of sound speed on air temperature, the wave characteristics are altered with changing temperature. Therefore, it is crucial to comprehend the impact of ambient air temperature on the properties of the compression wave in order to construct an aero-acoustically ideal railway tunnel system. The method of characteristics (MOC) has been used to solve Euler equations with steady and unsteady friction parameters in the current study. According to the findings, wave attenuation ratio is reducing along the tunnel length, and gradient is rising as train speed increases. The case study illustrates the key distance within a tunnel where the steepening ratio is at its highest point. This critical tunnel length is estimated to be 65 times the tunnel hydraulic diameter (300 km/h) for a particular air temperature (T = 323 K), and it decreases by 15% for a 70 K reduction (323K to 253K) in temperature. Similarly, the critical length falls by 40% for greater train speeds (500 km/h).https://www.jafmonline.net/article_2189_cef01b5d3eefab4bb8f1f9ad955c963a.pdfnon-linear effecttunnel aeroacousticsunsteady frictionwave distortionwave propagation |
| spellingShingle | R. S. Iyer D. H. Kim H. D. Kim Effect of Ambient Air Temperature on the Compression Wave Propagating along a Railway Tunnel Journal of Applied Fluid Mechanics non-linear effect tunnel aeroacoustics unsteady friction wave distortion wave propagation |
| title | Effect of Ambient Air Temperature on the Compression Wave Propagating along a Railway Tunnel |
| title_full | Effect of Ambient Air Temperature on the Compression Wave Propagating along a Railway Tunnel |
| title_fullStr | Effect of Ambient Air Temperature on the Compression Wave Propagating along a Railway Tunnel |
| title_full_unstemmed | Effect of Ambient Air Temperature on the Compression Wave Propagating along a Railway Tunnel |
| title_short | Effect of Ambient Air Temperature on the Compression Wave Propagating along a Railway Tunnel |
| title_sort | effect of ambient air temperature on the compression wave propagating along a railway tunnel |
| topic | non-linear effect tunnel aeroacoustics unsteady friction wave distortion wave propagation |
| url | https://www.jafmonline.net/article_2189_cef01b5d3eefab4bb8f1f9ad955c963a.pdf |
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