Visual analytics towards axle health of high-speed train based on large-scale scatter image

Flow structure over bluff bodies is more complex in wake. The wake is characterized by the unsteady behavior of the flow, large scale turbulent structure and strong recirculation region. For the case of high speed train, wake can be observed at the gap between the coaches and also on the rear coach. Wakes formation of high speed train are generated by free shear layer that is originated from the flow separation due to the sudden change in geometry. RANS and LES turbulent models are used in this paper to stimulate the formation of wakes and behavior of the flow over a simplified high speed train model. This model consists of two coaches with the gap between them is 0.5D. A total of four simulations have been made to study the effect of computational domain size and grid resolution on wake profiles of a simplified high speed train. The result shows that the computational domain can be reduced by decreasing the ground distance to 1.5D without affecting the magnitude of the wake profile. Both RANS and LES can capture the formation of the wake, but LES requires further grid refinement as the results between the two grid resolutions are grid dependent.

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Simulation Analysis of a Multiple-Vehicle, High-Speed Train Collision Using a Simplified Model

Shock and Vibration ◽

10.1155/2018/9504141 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Suchao Xie ◽

Weilin Yang ◽

Ping Xu

Keyword(s):

Finite Element ◽

Finite Element Model ◽

High Speed ◽

Large Scale ◽

Computing Time ◽

Element Model ◽

Vehicle Body ◽

Railway Vehicle ◽

Storage Space ◽

High Speed Train

To solve the problems associated with multiple-vehicle simulations of railway vehicles including large scale modelling, long computing time, low analysis efficiency, need for high performance computing, and large storage space, the middle part of the train where no plastic deformation occurs in the vehicle body was simplified using mass and beam elements. Comparative analysis of the collisions between a single railway vehicle (including head and intermediate vehicles before, and after, simplification) and a rigid wall showed that variations in impact kinetic energy, internal energy, and impact force (after simplification) are consistent with those of the unsimplified model. Meanwhile, the finite element model of a whole high-speed train was assembled based on the simplified single-vehicle model. The numbers of nodes and elements in the simplified finite element model of the whole train were 63.4% and 61.6%, respectively, compared to those of the unsimplified model. The simplified whole train model using the above method was more accurate than the multibody model. In comparison to the full-size finite element model, it is more specific, had more rapid computational speed, and saved a large amount of computational power and storage space. Finally, the velocity and acceleration data for every car were discussed through the analysis of the collision between two simplified trains at various speeds.

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Design of large-scale streamlined head cars of high-speed trains and aerodynamic drag calculation

Archives of Transport ◽

10.5604/01.3001.0010.6164 ◽

2017 ◽

Vol 44 (4) ◽

pp. 89-97 ◽

Cited By ~ 2

Author(s):

Zhenfeng Wu ◽

Enyu Yang ◽

Wangcai Ding

Keyword(s):

High Speed ◽

Large Scale ◽

Production Control ◽

Aerodynamic Drag ◽

Design Method ◽

Control Point ◽

Surface Characteristics ◽

High Speed Train ◽

Research Subjects ◽

High Speed Trains

Aerodynamic drag plays an important role in high-speed trains, and how to reduce the aerodynamic drag is one of the most important research subjects related to modern railway systems. This paper investigates a design method for large-scale streamlined head cars of high-speed trains by adopting NURBS theory according to the outer surface characteristics of trains. This method first created the main control lines of the driver cab by inputting control point coordinates; then, auxiliary control lines were added to the main ones. Finally, the reticular region formed by the main control lines and auxiliary ones were filled. The head car was assembled with the driver cab and sightseeing car in a virtual environment. The numerical simulation of train flow field was completed through definition of geometric models, boundary conditions, and space discretization. The calculation results show that the aerodynamic drag of the high-speed train with large-scale streamlined head car decreases by approximately 49.3% within the 50-300 km/h speed range compared with that of the quasi-streamlined high-speed train. This study reveals that the high-speed train with large-scale streamlined head car could achieve the purpose of reducing running aerodynamic drag and saving energy, and aims to provide technical support for the subsequent process design and production control of high-speed train head cars.

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Planning and Building Large-Scale Projects in the United States: California High-Speed Train Project Case Study

Urban Public Transportation Systems 2013 ◽

10.1061/9780784413210.020 ◽

2013 ◽

Author(s):

K. G. Sislak ◽

R. C. Vandenberg

Keyword(s):

United States ◽

High Speed ◽

Large Scale ◽

The United States ◽

High Speed Train

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Prediction of Welding Deformations of CRH380 Aluminum Alloy Side-Wall with Equivalent Thermal Load Method Based on Inherent Strain

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.652-654.2303 ◽

2013 ◽

Vol 652-654 ◽

pp. 2303-2310 ◽

Cited By ~ 1

Author(s):

Ya Na Li ◽

Su Ming Xie ◽

Jian Hui Zhang

Keyword(s):

Aluminum Alloy ◽

Thermal Load ◽

High Speed ◽

Large Scale ◽

Welding Process ◽

Side Wall ◽

Welding Distortion ◽

High Speed Train ◽

And Control ◽

Inherent Strain

The manufacture core of CRH380 high-speed train is aluminum alloy welding technology. However, welding residual distortion which occurs in welding process brings unfavorable effect on the quality of high-speed train. As a result, welding distortion forecasting and control become an important and urgent research topic in railway vehicles. Using equivalent thermal load method based on inherent strain given by the formulae, the welding distortion of aluminum alloy side-wall was predicted by an Elastic FEM which consider actual welding conditions. The simulation results were compared with experimentally measured data to evaluate the validity of the model and to verify effectiveness of this method for large-scale welding structure which had long seams.

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A Simple and Efficient Numerical Method for Dynamic Interaction Analysis of a High-Speed Train and Railway Structure During an Earthquake

Journal of Computational and Nonlinear Dynamics ◽

10.1115/1.2960482 ◽

2008 ◽

Vol 3 (4) ◽

Cited By ~ 35

Author(s):

M. Tanabe ◽

N. Matsumoto ◽

H. Wakui ◽

M. Sogabe ◽

H. Okuda ◽

...

Keyword(s):

Numerical Method ◽

High Speed ◽

Large Scale ◽

Interaction Analysis ◽

Plastic Material ◽

Equations Of Motion ◽

Material Model ◽

Dynamic Interaction ◽

Contact Dynamics ◽

High Speed Train

In this paper, a simple and efficient numerical method to solve for the dynamic interaction of a high-speed train and railway structure during an earthquake is given. The motion of the train is modeled in multibody dynamics with nonlinear springs and dampers used to connect components. An efficient mechanical model for contact dynamics between the wheel and rail during an earthquake is presented. The railway structure is modeled with various finite elements. A nonlinear spring element based on a trilinear elastic-plastic material model is given for the concrete railway structure during an earthquake. A substructure model where a train runs repeatedly has been devised to obtain an approximated combined motion of the long train with many cars connected and the railway structure during an earthquake. A modal method has been developed to solve large-scale nonlinear equations of motion of the train and railway structure effectively. Based on the present method, a computer program DIASTARS for the dynamic interaction analysis of a Shinkansen train (high-speed train in Japan) and the railway structure during an earthquake has been developed. Numerical examples are demonstrated.

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