High-Speed Passenger and Intercity Train Aerodynamic Computer Modeling

2000 ◽  
Author(s):  
Samuel Holmes ◽  
Martin Schroeder ◽  
Elton Toma
Keyword(s):  
United States ◽  
Wind Speed ◽  
Computational Fluid Dynamic ◽  
High Speed ◽  
Fluid Dynamic ◽  
The United States ◽  
Motion Simulation ◽  
High Speed Train ◽  
Aerodynamic Loads ◽  
Train Speed

Abstract With the onset of high-speed passenger train service in the United States, the Federal Railroad Administration (FRA) and railroad agencies are concerned with the aerodynamic effects these trains will have on lightweight freight equipment, such as empty double stack container cars. This paper presents the results of a research project that evaluated this interaction. In this study we conducted a series of computational fluid dynamic (CDF) calculations to characterize the aerodynamic loads on a container consist passed by a high-speed train. A train motion simulation program was used to determine resultant motion and risk of overturning or derailment of the container consist. Numerous cases were studied in which train speed and wind speed and direction were varied.

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.

scholarly journals Benchmark of the Trends of Spatial Inequality in World Megaregions

2021 ◽  
Vol 13 (11) ◽  
pp. 6456
Author(s):  
Ziqi Liu ◽  
Ming Zhang ◽  
Liwen Liu
Keyword(s):  
United States ◽  
High Speed ◽  
Investment Strategy ◽  
The United States ◽  
Spatial Inequality ◽  
Theil Index ◽  
High Speed Rail ◽  
International Learning ◽  
Regional Product ◽  
Index Measure

There have been growing concerns around the world over the rising spatial inequality (SI) amid fast and vast globalization. This paper presents an effort to benchmark the conditions and trends of spatial inequality in 37 megaregions in the United States, Europe, and China. Furthermore, the study selected three megaregion examples and analyzed the effect of developing high-speed rail (HSR) as an infrastructure investment strategy on reshaping the spatial pattern of job accessibility. The study measures spatial inequality with the Theil index of gross regional product and with the rank-size coefficient of polycentricity. Results show that spatial inequality exists and varies in magnitude within and between megaregions. On average, Chinese megaregions exhibited the level of spatial inequality about two times or more of those in the U.S. and European megaregions. The decade between 2006 and 2016 saw a decrease in the Theil index measure of megaregional inequality in China, but a slight increase in the United States and Europe. Fast growing megaregions exhibit high levels and rising trends of spatial inequality regardless of the country or continent setting. HSR helps improve mobility and accessibility; yet the extent to which HSR reduces spatial inequality is context dependent. This study presents a first attempt to assess and compare the spatial inequality conditions and trajectories in world megaregions aiming at promoting international learning.

Design of High-Speed Railway Bridges with Earthquakes in the United States

2018 ◽  
Vol 29 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Yinghong Cao ◽  
Todd Ude ◽  
Daniel Getter ◽  
Brendan Gill
Keyword(s):  
United States ◽  
High Speed ◽  
The United States ◽  
High Speed Railway ◽  
Railway Bridges

scholarly journals Numerical studies on aerodynamics of high-speed railway train subjected to strong crosswind

2019 ◽  
Vol 11 (11) ◽  
pp. 168781401988727
Author(s):  
Xu Wang ◽  
Yuanhao Qian ◽  
Zengshun Chen ◽  
Xiao Zhou ◽  
Huaqiang Li ◽  
...  
Keyword(s):  
Wind Speed ◽  
High Speed ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Width Ratio ◽  
Force Coefficient ◽  
Rolling Moment ◽  
Side Force ◽  
Train Speed ◽  
Yaw Angle

Under the action of strong crosswind, the aerodynamic behavior of a rail vehicle at high speed will be changed significantly, which could directly affect the safe operation of the vehicle. With the help of the shape of train used in China, the aerodynamic characteristics of trains with scale of 1:1 is investigated using computational fluid dynamics numerical simulation method, which consists of the variation of aerodynamics force and moment with wind yaw angle, wind speed, train speed, and nose shape. After an initial validation against Baker’s results from wind tunnel test, the numerical model is then used to investigate the aerodynamic characteristics of the trains. The numerical results indicate that lift coefficient of the M train is slightly higher than TMC1 and TMC2 trains. Regardless of aerodynamics force coefficients, TMC1 reaches the maximum at a yaw angle of 75°. Aerodynamics force coefficient increases with both wind speed and train speed, but the change of which is not linear. Comparing aerodynamic force with different geometric dimensions of train nose, it is shown that height–width ratio is insensitive to side force and rolling moment, but sensitive to lift force from the yaw angle 0°–90°. The side force coefficient, as we most concern, is less than other results, when the length–width ratio is 1 and height–width is 0.87.

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.

On the aerodynamic loads when a high speed train passes under an overhead bridge

2020 ◽  
Vol 202 ◽  
pp. 104208 ◽  
Author(s):  
Xi-Feng Liang ◽  
Xiao-Bai Li ◽  
Guang Chen ◽  
Bo Sun ◽  
Zhe Wang ◽  
...  
Keyword(s):  
High Speed ◽  
High Speed Train ◽  
Aerodynamic Loads
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