scholarly journals MATLAB Simulation of Current-Carrying Friction between Catenary and Bow Net Of High-Speed Train under Fluctuating Load

2021 ◽  
Vol 2143 (1) ◽  
pp. 012006
Author(s):  
Ruyu Wang ◽  
Zhiguo Zhang
Keyword(s):  
Carrying Capacity ◽  
High Speed ◽  
High Speed Train ◽  
Matlab Simulation ◽  
Continuous Change ◽  
Running Speed ◽  
Train Speed

Abstract The current carrying capacity of pantograph-catenary will also change dynamically with the continuous change of train speed. The influence of internal and external parameters such as running speed, current, pressure and vibration must be fully considered. Based on this, this paper first analyses the action relationship between CRH pantograph-catenary under fluctuating load, then studies the measurement of current carrying friction between CRH pantograph-catenary under fluctuating load, and finally gives the MATLAB simulation of current carrying friction between pantograph-catenary under fluctuating load.

scholarly journals Source Contribution Analysis for Exterior Noise of a High-Speed Train: Experiments and Simulations

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Jie Zhang ◽  
Xinbiao Xiao ◽  
Dewei Wang ◽  
Yan Yang ◽  
Jing Fan
Keyword(s):  
High Speed ◽  
Noise Source ◽  
High Speed Train ◽  
Noise Sources ◽  
Sound Sources ◽  
Lower Region ◽  
Source Contribution ◽  
Array Measurements ◽  
Noise Characteristics ◽  
Train Speed

This paper presents a detailed investigation into the contributions of different sound sources to the exterior noise of a high-speed train both experimentally and by simulations. The in situ exterior noise measurements of the high-speed train, including pass-by noise and noise source identification, are carried out on a viaduct. Pass-by noise characteristics, noise source localizations, noise source contributions of different regions, and noise source vertical distributions are considered in the data analysis, and it is shown how they are affected by the train speed. An exterior noise simulation model of the high-speed train is established based on the method of ray acoustics, and the inputs come from the array measurements. The predicted results are generally in good agreement with the measurements. The results show that for the high-speed train investigated in this paper, the sources with the highest levels are located at bogie and pantograph regions. The contributions of the noise sources in the carbody region on the pass-by noise increase with an increasing distance, while those in the bogie and train head decrease. The source contribution rates of the bogie and the lower region decrease with increasing train speed, while those of the coach centre increase. At a distance of 25 m, the effect of the different sound sources control on the pass-by noise is analysed, namely, the lower region, bogie, coach centre, roof region, and pantograph. This study can provide a basis for exterior noise control of high-speed trains.

A Study on Speed Elevation Possibility at the Connection between High Speed Lines and Conventional Lines with Korean High Speed Train

2006 ◽  
Vol 326-328 ◽  
pp. 635-638 ◽  
Author(s):  
Young Sam Ham ◽  
Jai Sung Hong
Keyword(s):  
Contact Force ◽  
High Speed ◽  
Integrated System ◽  
Communication Line ◽  
Mass Transportation ◽  
Test Results ◽  
High Speed Train ◽  
Safety Standards ◽  
Derailment Coefficient ◽  
Train Speed

Railways are a mass transportation system with high safety and punctuality. These strengths have been well proved by tests and evaluations. Railways are an integrated system with cars, power, signal, communication, line structures and operation. Among many safety standards of these systems, contact force between wheels and lines can be chosen since a derailment coefficient evaluated by contract force is the most important fact that decides the safety of railways. Especially regarding express trains, since they run twice faster than conventional ones, the evaluation of a derailment coefficient is more important than any other criteria. Currently, Korean express trains between Seoul and Pusan use the same stations as conventional trains in Daejeon and Dong-Daegu; therefore, express trains run on conventional lines from express lines. This paper describes test results acquired by increasing the train speed where express lines and conventional lines are connected. Test results tell that it is safe with under 0.8 derailment coefficient and running time is reduced by 10~30 seconds in each section.

scholarly journals A Numerical Study of the Screening Effectiveness of Open Trenches for High-Speed Train-Induced Vibration

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Chih-hung Chiang ◽  
Pei-hsun Tsai
Keyword(s):  
Poisson’S Ratio ◽  
High Speed ◽  
Numerical Study ◽  
Cutoff Frequency ◽  
Poisson's Ratio ◽  
High Speed Train ◽  
High Speed Rail ◽  
Train Speed ◽  
Open Trench ◽  
Screening Effectiveness

This study used the 2D boundary element method in time domain to examine the screening effectiveness of open trenches on reducing vibration generated by a high-speed train. The parameters included configurations of the trench, train speed, the distance between the source and the trench, and the Poisson’s ratio of the soil. A reducing displacement level (in dB scale) was defined and used to evaluate the screening effectiveness of a wave barrier. The maximal reducing displacement level reached 25 dB when an open trench was used as a wave barrier. The depth of an open trench is a main influential parameter of screening effectiveness. The cutoff frequency of the displacement spectrum increases with decreasing trench depth. The maximal screening effectiveness occurs when the depth is 0.3-0.4 Rayleigh wavelength. Using an open trench as a wave barrier can reduce 10–25 dB of vibration amplitude at frequencies between 30 and 70 Hz. A considerable increase in screening effectiveness of the open trench was observed from 30 to 70 Hz, which matches the main frequencies of vibration induced by Taiwan High Speed Rail. The influence of trench width on screening effectiveness is nonsignificant except for frequencies from 30 to 40 Hz. Poisson’s ratio has various effects on the reduction of vibration at frequencies higher than 30 Hz.

Out-of-Plane Responses of Overspeeding High-Speed Train on Curved Track

2018 ◽  
Vol 18 (11) ◽  
pp. 1850132 ◽  
Author(s):  
Jian Dai ◽  
Kok Keng Ang ◽  
Van Hai Luong ◽  
Minh Thi Tran ◽  
Dongqi Jiang
Keyword(s):  
High Speed ◽  
Numerical Study ◽  
Contact Forces ◽  
Railway Track ◽  
High Speed Train ◽  
Track Segment ◽  
Out Of Plane ◽  
Train Speed ◽  
Curved Track ◽  
Design Speed

This paper presents a numerical study on the out-of-plane responses of a high-speed train running on a curved railway track segment using the moving element method. The accuracy and efficiency of the proposed computation model presented herein are compared with available analytical results from the literature and a finite element solver based on a simplified moving load model. Thereafter, a half-railcar moving sprung-mass model and a double-rail track-foundation model are presented to investigate the behavior of a high-speed train traversing a curved track, particularly when the train speed is greater than the design speed of the curved track segment. The results show that the train speed and severity of track irregularity significantly affect the contact forces on the rails. This paper also presents a case of a railcar overturning when the train speed is greater than 2.5 times the design speed of a curved track segment.

scholarly journals Influences of High-Speed Train Speed on Tunnel Aerodynamic Pressures

2021 ◽  
Vol 12 (1) ◽  
pp. 303
Author(s):  
Jianming Du ◽  
Qian Fang ◽  
Jun Wang ◽  
Gan Wang
Keyword(s):  
High Speed ◽  
Peak Pressure ◽  
Stage I ◽  
Stage Ii ◽  
Stage Iii ◽  
High Speed Train ◽  
Railway Tunnel ◽  
Maximum Peak ◽  
Train Speed ◽  
Three Stages

To comprehensively investigate the characteristics of aerodynamic pressures on a tunnel caused by the whole tunnel passage of a high-speed train at different speeds, we conduct a series of three-dimensional numerical simulations. Based on the field test results obtained by other researchers, the input parameters of our numerical simulation are determined. The process of a high-speed train travelling through a railway tunnel is divided into three stages according to the spatial relationship between the train and tunnel. Stage I: before train nose enters the entrance; Stage II: while the train body runs inside the tunnel; Stage III: after the train tail leaves the exit. The influences of high-speed train speed on the tunnel aerodynamic pressures of these three stages are systematically investigated. The results show that the maximum peak pressure value decreases with increasing distance from the entrance and increases with increasing train speed in Stage I. There is an approximately linear relationship between the three types of maximum peak pressure (positive peak, negative peak, and peak-to-peak pressures) and the power of the train speed in Stage II. These three types of maximum peak pressure values of the points near tunnel portals increase with increasing train speed in Stage III. Moreover, these three types of maximum peak pressure in the tunnel’s middle section at different train speeds are more complex than those near the tunnel portals, and there is one or more turning points due to the superimposed effects of different pressure waves.

Flutter Study on High Speed Train External Windshield by a Tight Coupling Method

2019 ◽  
Author(s):  
Qian Jiang ◽  
Guannan Zheng ◽  
Guilin Zhao
Keyword(s):  
Information Transfer ◽  
High Speed ◽  
Stable State ◽  
Coupling Method ◽  
Coupling Scheme ◽  
Displacement Curve ◽  
High Speed Train ◽  
Tight Coupling ◽  
Time Step ◽  
Train Speed

Abstract Flutter is a complex problem caused by the interaction between the elastic structure and the flow field around that. In this paper a study of flutter on high speed train external windshield is presented. Here, a coupling scheme of computational fluid dynamics (CFD) and computational structure dynamics (CSD) is applied to simulate the flutter problems. Specifically, some key technologies like tight coupling method, information transfer and mesh deformation strategy are involved. Repeatedly exchanging information in the sub-iteration of physical time step is basically typical of tight coupling method, which is a second-order accuracy method. This flutter methodology has been applied for standard model AGARD 445.6 wing and other engineering examples, with lots of excellent results obtained. In this high speed train external windshield flutter research, eight train speed conditions are chosen to simulate the flutter issue, including 250km/h, 300km/h, 350km/h, 400 km/h, 450 km/h, 500 km/h, 550 km/h and 600 km/h. As for structural model, the first 30 order modes of elastic windshield are taken into consideration for CFD/CSD coupling simulation. In addition, it is defined to be the flutter boundary once the generalized displacement curve performing as persistent oscillation, which is the critical stable state for the vibration of external windshield. According to the research, under a specific train speed condition, adjustment of modal eigenfrequency can lead to the change of vibration stability. Furthermore, it is found that there is a positive correlation between train speed and modal eigenfrequency. So the optimal windshield scheme under different operating speeds is proposed that in order for the convergent vibration, a measure of changing eigenfrequency can be taken to ensure the vibration convergent and flutter cannot occur.

Analysis of Dynamic Wind of Sound Barrier under High Speed Train

2013 ◽  
Vol 361-363 ◽  
pp. 1536-1542
Author(s):  
Zhou Shi ◽  
Jun Li Guo ◽  
Wei Feng Su ◽  
Shuang Yang Zhang
Keyword(s):  
High Speed ◽  
Measured Data ◽  
Air Pressure ◽  
Turbulent Model ◽  
High Speed Train ◽  
Sound Barrier ◽  
Barrier Region ◽  
High Speed Trains ◽  
Train Speed ◽  
Volume Method

The special dynamic pulsating air pressure acting on the surface of sound barrier can be aroused by passing high speed train, making sound barrier structure and components prone to destruction and other issues. Based 3-D unsteady k-ε two-equation turbulent model, dynamic processes of high-speed trains passing the sound barrier region at different speeds and many factors are simulated and analyzed by using moving mesh finite volume method. The results of dynamic numerical calculated pulsating air pressure results and the effecting rule of various parameters were obtained, and compared with the measured data. It is showed that the air pressure value increases with the increasing train speed and the dynamic numerical calculated pulsating air pressure curves shape and effecting rule of parameters are all well matched with the measured data, but the air pressure value is slightly larger. At last, based on the results of numerical calculation, the addition of static air pressure value caused by high speed train is put forward.

Research into the Parameter Influence on Coupled Vibration Analysis of High Speed Train and Bridge

2011 ◽  
Vol 90-93 ◽  
pp. 884-889
Author(s):  
Chang Jian Tan ◽  
Wen Hong Ji
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Railway Track ◽  
Vertical Acceleration ◽  
High Speed Train ◽  
Coupled Vibration ◽  
Train Speed ◽  
Response Increase ◽  
Track Irregularity ◽  
Parameter Influence

To investigate the characteristic of coupled vibration of high speed train and bridge, the effect of the railway track irregularity, different train speeds were investigated based on analyzing the coupled vibration of the JR300 high speed train-bridge system The results show that the vertical acceleration of train will be influenced much when the railway track irregularity is considered. The study suggests that the dynamic response of the train and bridge decreases with an increase in the train speed, when the train speed is at a certain zone, and the dynamic response increase rapidly with the increased train speed when the train speed is out of this zone.

The Analysis of Aerodynamic Characteristics of the High-Speed Train in Different Railway Conditions under Crosswinds

2013 ◽  
Vol 774-776 ◽  
pp. 58-63
Author(s):  
Kun Ye ◽  
Ren Xian Li
Keyword(s):  
Numerical Calculation ◽  
Wind Speed ◽  
Traffic Safety ◽  
Linear Relation ◽  
High Speed ◽  
Aerodynamic Characteristics ◽  
High Speed Train ◽  
Transverse Loads ◽  
Train Speed ◽  
Calculation Models

The numerical calculation models of the high-speed train in the straight and different radius curve railway are established. Author calculated transverse forces (moments) acting on the three sections (first train, middle train and rear train). At the same time, under with the shelter wind wall and without the wall, the change trends of side forces coefficients and rolling moments coefficients of trains with the train speed and the transverse wind speed are analyzed. Results show that, in the straight railway and curve railway, transverse loads coefficients increase with the increase of the transverse wind speed and decrease with the increase of the train speed. The transverse forces (moments) of the three sections of the train with the shelter wind wall are opposite to that without the wall. Traffic safety under crosswinds focuses on the rear train with the shelter wind wall and focuses on the first train without the wall. At the same train speed and transverse wind speed, side forces and rolling moments of trains in curve railway is greater than that of trains in straight railway. Absolute values of transverse loads coefficients decreased gradually with the increase of the radius of the curve, and their relationship basically is the linear relation.

Research on the Influence of Train Speed Change on the EMI of Pantograph-Catenary Arc to Main Navigation Stations

2021 ◽  
Vol 36 (4) ◽  
pp. 450-457
Author(s):  
Yutao Tang ◽  
Feng Zhu ◽  
Yingying Chen
Keyword(s):  
Power Supply ◽  
Electromagnetic Interference ◽  
High Speed ◽  
Electric Field Intensity ◽  
High Speed Train ◽  
Frequency Range ◽  
Speed Limits ◽  
Train Speed ◽  
Speed Change ◽  
Neutral Section

The electromagnetic interference (EMI) of the pantograph-catenary arc (PCA) to the main navigation stations will be affected when the speed of the high-speed train is changed. In order to study the influence of the speed change, we measured and analyzed the electric field intensity of the PCA generated at common and neutral section of power supply line at different train speeds. The frequency range in this study is the frequency of the main navigation stations (108 ~ 336 MHz). Both theoretical and experimental results show that PCA radiation increases with the increase of train speed. Besides, we calculated the maximum train speed without interfering the navigation signal. This work is useful for estimating EMI of the PCA at different train speeds and mitigating the interference to the navigation station near the highspeed railway by proposing corresponding speed limits.

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