scholarly journals Numerical study on aerodynamic characteristics of high-speed trains with considering thermal-flow coupling effects

2017 ◽  
Vol 19 (7) ◽  
pp. 5606-5626 ◽  
Author(s):  
Hong Wei Xing ◽  
Ai Min Yang ◽  
Yi Fan Li ◽  
Ling Zhang ◽  
Li Jing Feng ◽  
...  
Keyword(s):  
High Speed ◽  
Numerical Study ◽  
Aerodynamic Characteristics ◽  
Thermal Flow ◽  
Coupling Effects ◽  
Flow Coupling ◽  
High Speed Trains

The Aerodynamic Characteristics of the Pantograph When the Train Passes Through the Tunnel

2017 ◽  
Author(s):  
Dilong Guo ◽  
Wen Liu ◽  
Junhao Song ◽  
Ye Zhang ◽  
Guowei Yang
Keyword(s):  
High Speed ◽  
Aerodynamic Force ◽  
Maximum Amplitude ◽  
Aerodynamic Characteristics ◽  
High Speed Train ◽  
Expansion Waves ◽  
Compression And Expansion ◽  
High Speed Trains ◽  
Current Characteristics ◽  
Pass Through

The aerodynamic force acting on the pantograph by the airflow is obviously unsteady and has a certain vibration frequency and amplitude, while the high-speed train passes through the tunnel. In addition to the unsteady behavior in the open-air operation, the compressive and expansion waves in the tunnel will be generated due to the influence of the blocking ratio. The propagation of the compression and expansion waves in the tunnel will affect the pantograph pressure distribution and cause the pantograph stress state to change significantly, which affects the current characteristics of the pantograph. In this paper, the aerodynamic force of the pantograph is studied with the method of the IDDES combined with overset grid technique when high speed train passes through the tunnel. The results show that the aerodynamic force of the pantograph is subjected to violent oscillations when the pantograph passes through the tunnel, especially at the entrance of the tunnel, the exit of the tunnel and the expansion wave passing through the pantograph. The changes of the pantograph aerodynamic force can reach a maximum amplitude of 106%. When high-speed trains pass through tunnels at different speeds, the aerodynamic coefficients of the pantographs are roughly the same.

Numerical study of the air flow through an air-conditioning unit on high-speed trains

2019 ◽  
Vol 187 ◽  
pp. 26-35 ◽  
Author(s):  
Xueliang Li ◽  
Fan Wu ◽  
Yu Tao ◽  
Mingzhi Yang ◽  
Robert Newman ◽  
...  
Keyword(s):  
Air Conditioning ◽  
High Speed ◽  
Numerical Study ◽  
Air Flow ◽  
High Speed Trains ◽  
Flow Through

Influence of Typical Subgrade Structures on Aerodynamic Characteristics of High Speed Trains in Cross Wind Conditions

2018 ◽  
Author(s):  
Zhenxu Sun ◽  
Guowei Yang
Keyword(s):  
High Speed ◽  
Aerodynamic Characteristics ◽  
Wind Condition ◽  
Safety Control ◽  
High Speed Trains ◽  
Flow Field Characteristics ◽  
Wind Velocities ◽  
The Cross ◽  
Train Safety

Due to geographical and environmental constraints, highspeed railways use a variety of subgrade structures such as ground, embankments with different height, viaducts, etc. When trains run on embankments and viaducts, the flow around the car body is more complex than the ground. Under the action of crosswind, there are obvious differences in the cross-wind aerodynamic characteristics of high-speed trains on different subgrade structures. The unreasonable subgrade structure will affect the cross-wind safety of the train. At the same time, the structure of the train is complex, the bogie and pantograph have an important role on the flow field characteristics of the train, and the over simplified profile of the short train cannot accurately reflect the true aerodynamic characteristics of the train. In the present paper, in order to study the influence of typical subgrade structure on the aerodynamic characteristics of high speed trains, a real high-speed train with 9 carriages at the speed of 200 km/h was taken for case study, and the details of windshields, bogies and pantographs were taken into consideration. The cross wind velocities were chosen as 20, 30, 35 and 40 m/s. The aerodynamics performance of the highspeed train under the four conditions of plane ground, 3m-embankment, 6m-embankment and viaduct were simulated and compared, and the differences and regularities in the aerodynamic characteristics under cross wind conditions on different subgrade were analyzed. The results provide a reference for train safety control on complex subgrade structures under cross wind condition.

scholarly journals Influence of pantograph fixing position on aerodynamic characteristics of high-speed trains

2017 ◽  
Vol 25 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Liang Zhang ◽  
Jiye Zhang ◽  
Tian Li ◽  
Weihua Zhang
Keyword(s):  
High Speed ◽  
Aerodynamic Characteristics ◽  
High Speed Trains

scholarly journals Active Control of Contact Force for a Pantograph-Catenary System

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Jiqiang Wang
Keyword(s):  
Active Control ◽  
Contact Force ◽  
High Speed ◽  
Large Scale ◽  
Vibration Suppression ◽  
Numerical Study ◽  
Primary Objective ◽  
Geometric Framework ◽  
High Speed Trains ◽  
Catenary System

The performance of the high speed trains depends critically on the quality of the contact in the pantograph-catenary interaction. Maintaining a constant contact force needs taking special measures and one of the methods is to utilize active control to optimize the contact force. A number of active control methods have been proposed in the past decade. However, the primary objective of these methods has been to reduce the variation of the contact force in the pantograph-catenary system, ignoring the effects of locomotive vibrations on pantograph-catenary dynamics. Motivated by the problems in active control of vibration in large scale structures, the author has developed a geometric framework specifically targeting the remote vibration suppression problem based only on local control action. It is the intention of the paper to demonstrate its potential in the active control of the pantograph-catenary interaction, aiming to minimize the variation of the contact force while simultaneously suppressing the vibration disturbance from the train. A numerical study is provided through the application to a simplified pantograph-catenary model.

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