scholarly journals The influence of reduced cross-section on pressure transients from high-speed trains intersecting in a tunnel

2020 ◽  
Vol 201 ◽  
pp. 104161 ◽  
Author(s):  
Yibin Lu ◽  
Tiantian Wang ◽  
Mingzhi Yang ◽  
Bosen Qian
Keyword(s):  
Cross Section ◽  
High Speed ◽  
Reduced Cross Section ◽  
Pressure Transients ◽  
High Speed Trains

scholarly journals Risks of Ear Complaints of Passengers and Drivers While Trains Are Passing Through Tunnels at High Speed: A Numerical Simulation and Experimental Study

2019 ◽  
Vol 16 (7) ◽  
pp. 1283 ◽  
Author(s):  
Pengpeng Xie ◽  
Yong Peng ◽  
Tiantian Wang ◽  
Honghao Zhang
Keyword(s):  
High Speed ◽  
Fe Model ◽  
Analysis Method ◽  
High Speed Train ◽  
Pressure Transients ◽  
Operation Speed ◽  
High Speed Trains ◽  
Recorded Data ◽  
Four Levels ◽  
Human Middle Ear

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.

scholarly journals Complexity Simulation on Application of Asymmetric Bionic Cross-Section Rod in Pantographs of High-Speed Trains

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yan Cao ◽  
Yu Bai ◽  
Qiangfeng Wang
Keyword(s):  
Noise Reduction ◽  
Porous Materials ◽  
Cross Section ◽  
High Speed ◽  
Aerodynamic Resistance ◽  
Aerodynamic Noise ◽  
Practical Application ◽  
Bionic Design ◽  
High Speed Trains ◽  
Bionic Structure

Ground transportation means and aircrafts with high-speed running are composed of many rod components. Aerodynamic noise generated therefrom is very outstanding. Reduction of the aerodynamic noise of rods becomes a hot topic in recent years. Most reported studies are tentative researches on aerodynamic noise of a pantograph or involve noise reduction of the pantograph with using porous materials or reshaping rod surfaces. Through using porous materials and reshaping rod surface, the aerodynamic noise of pantograph can be reduced to a certain extent, but the aerodynamic resistance will be increased and it is not convenient for practical application in engineering. Regarding this situation, the paper explores noise reduction performance of a feather on the back of a carrier pigeon and conducts the bionic design on rod surface. Through numerical simulation, the paper researches noise reduction performance of the bionic structure on the rod surface, reveals the mechanism of bionic noise reduction, and explores noise reduction effects of bionic structural rods on pantographs of the high-speed trains.

scholarly journals Multiobjective Railway Alignment Optimization Using Ballastless Track and Reduced Cross-Section in Tunnel

2021 ◽  
Vol 13 (19) ◽  
pp. 10672
Author(s):  
Salvatore Antonio Biancardo ◽  
Francesco Avella ◽  
Ernesto Di Lisa ◽  
Xinqiang Chen ◽  
Francesco Abbondati ◽  
...  
Keyword(s):  
Cross Section ◽  
High Speed ◽  
Geometric Constraints ◽  
Railway Track ◽  
Reduced Cross Section ◽  
Highway Projects ◽  
Ballastless Track ◽  
Planning And Design ◽  
Railway Planning ◽  
Design Speed

The increasing need for railway planning and design to connect growing cities in inland mountainous areas has pushed engineering efforts toward the research of railway tracks that must comply with more restrictive constraints. In this study, a multiobjective alignment optimization (HAO), commonly used for highway projects, was carried out to identify a better solution for constructing a high-speed railway track considering technical and economic feasibilities. Then, two different and innovative scenarios were investigated: an unconventional ballastless superstructure, which is more environment-friendly than a gravel superstructure, and a reduced cross-section in a tunnel, which enables a slower design speed and then, less restrictive geometric constraints and earthmoving. The results showed that the first solution obtained a better performance with a slight increase in cost. Moreover, both scenarios improved the preliminary alignment optimization, reducing the overall cost by 11% for the first scenario and 20% for the second one.

scholarly journals Pressure Transients Induced by High-Speed Trains Passing Each Other Inside a Tunnel

1995 ◽  
Vol 15 (Supplement2) ◽  
pp. 31-34
Author(s):  
Toshiyuki AOKI ◽  
Shinya MASHIMO ◽  
Kousuke FUNASAKI ◽  
Kazuyasu MATSUO
Keyword(s):  
High Speed ◽  
Pressure Transients ◽  
High Speed Trains

A tilting high temperature gas reaction chamber for the JEM 7A T.E.M.

1978 ◽  
Vol 36 (1) ◽  
pp. 70-71
Author(s):  
Brian L. Rhoades
Keyword(s):  
Cross Section ◽  
Reaction Chamber ◽  
Objective Lens ◽  
Reduced Cross Section ◽  
Cross Sectional ◽  
Structural Investigations ◽  
Transmission Electron ◽  
Dynamic Experiments ◽  
Successful Design ◽  
Thermocouple Junction

A gas reaction chamber has been designed and constructed for the JEM 7A transmission electron microscope which is based on a notably successful design by Hashimoto et. al. but which provides specimen tilting facilities of ± 15° aboutany axis in the plane of the specimen.It has been difficult to provide tilting facilities on environmental chambers for 100 kV microscopes owing to the fundamental lack of available space within the objective lens and the scope of structural investigations possible during dynamic experiments has been limited with previous specimen chambers not possessing this facility.A cross sectional diagram of the specimen chamber is shown in figure 1. The specimen is placed on a platinum ribbon which is mounted on a mica ring of the type shown in figure 2. The ribbon is heated by direct current, and a thermocouple junction spot welded to the section of the ribbon of reduced cross section enables temperature measurement at the point where localised heating occurs.

Battery Self-Traction System for High-Speed Trains

2020 ◽  
Vol 140 (5) ◽  
pp. 349-355
Author(s):  
Hirokazu Kato ◽  
Kenji Sato
Keyword(s):  
High Speed ◽  
High Speed Trains ◽  
Traction System
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