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| Deformation law of compression wavefront in long tunnel of high-speed railway |
| Received:February 21, 2018 Revised:April 18, 2018 |
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| DOI：10.7511/jslx20180221001 |
| KeyWord:high-speed train tunnel compression wave deformation numerical calculation |
| Author | Institution |
| 刘金通 |
西南交通大学 机械工程学院, 成都 |
| 李人宪 |
西南交通大学 机械工程学院, 成都 |
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| Abstract: |
| A compression wave will be generated when a high-speed train suddenly enters into a tunnel.The wavefront of the compression wave deforms as it is propagating in a long railway tunnel,which means the pressure gradient of the wavefront varies along the tunnel.The intensity of micro-pressure wave at the tunnel exit is proportional to the maximum pressure gradient of the compression wave,and the sonic boom at the tunnel exit is directly related to the intensity of the micro-pressure wave.So it is necessary to study the law of the compression wave deformation in long tunnel.In this paper,the generation and propagation process of the compression wave in a long tunnel are investigated by using three dimensional CFD method.It is proved that the deformation of the wavefront is not only related to friction between the air and the wall of the tunnel and the inertial motion of the compression wave,but also related to the motion of the train that is to say the train movement in the tunnel will input energy to the back of the compression wave and hence affect the deformation of the compression wavefront.Through the calculation of multiple operating conditions,the variation trend of the maximum pressure gradient and its appearance position relating to train speeds and to tunnel blockage ratios in a long railway tunnel are obtained. |