Reduction of pressure transients of high-speed train passing through a tunnel by cross-section increase

2018 ◽  
Vol 183 ◽  
pp. 235-242 ◽  
Author(s):  
Tiantian Wang ◽  
Fan Wu ◽  
Mingzhi Yang ◽  
Peng Ji ◽  
Bosen Qian
Author(s):  
Pengpeng Xie ◽  
Yong Peng ◽  
Tiantian Wang ◽  
Honghao Zhang

Ear complaints induced by interior pressure transients are common experiences for passengers and crew members when high-speed trains are passing through tunnels. However, approaches to assessing the risks of the pressure-related aural discomfort have not been reported until recently. The objective of this study was to evaluate the hazards of interior pressure transients of high-speed train on human ears combining the effects of operation speed and seal index. Moving model tests were conducted to obtain the pressure transients when the model train runs in the tunnel. The recorded data were transformed into the interior pressures by empirical formula. Furthermore, the aural sensations were divided into four levels hierarchically and the range for each level was derived by logistic regression analysis method and represented by three biomechanical metrics. Furthermore, a human middle ear finite element (FE) model was used to simulate its dynamics under the interior pressures. The results indicate that lifting operation speed from 250 km/h to 350 km/h in tunnel will prolong the duration of ear complaints by more than two times whereas improving the seal index from 4 s to 12 s will reduce the incidences of the onset of tinnitus and hearing loss by more than ten times. In addition, the duration of aural comfort shortens from the head car to the tail car against the running direction. It is desirable that enhancing the seal index improve the aural sensations of the passengers and crew members considering the lifting operation speed of high-speed train.


Author(s):  
Dan Zhou ◽  
Hong-qi Tian ◽  
Jian Zhang ◽  
Ming-zhi Yang

2004 ◽  
Vol 18 (9) ◽  
pp. 1614-1622 ◽  
Author(s):  
Nahmkeon Hur ◽  
Sa-Ryang Kim ◽  
Wook Kim ◽  
Sangyeul Lee

2012 ◽  
Vol 430-432 ◽  
pp. 2071-2074
Author(s):  
Li Hui Zhao ◽  
Ying Long Tao

The stiffness of the seat from CRH high speed train was studied. First, FEM analysis was performed on the entire seat and the backrest frame. Results showed that the backrest frame accounts for most of the seat’s deformation. Then a three factors and three levels orthogonal experiment was designed to find which component affects the stiffness of backrest. From the results of nine experiments, conclusion that side beams have the high sensitivity on seat stiffness. Finally, size optimization was carried on to find best cross section of the side beam. The FEM analysis of new design showed that the maximum deformation of the seat was 9.27mm, decreased by 24.1% compared with original design


1999 ◽  
Vol 385 ◽  
pp. 63-78 ◽  
Author(s):  
M. S. HOWE

Rayleigh's (1926, Appendix A) method for the approximate calculation of potential flow from the open end of a semi-infinite flanged cylinder is applied to obtain analytical representations of Green's function describing the generation of sound waves within a flanged cylinder by sources located in the neighbourhood of the open end. Detailed results are given for the circular cylinder considered by Rayleigh and extension made to a flanged cylinder of rectangular cross-section. The validity of various approximations is assessed by comparison with the exact solution available (by the method of conformal transformation) for potential flow from a two-dimensional, flanged duct. The results are used to compare the profiles and the pressure gradients of compression waves generated when a high-speed train enters tunnels of circular and rectangular cross-sections.


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