Study on the Aerodynamic Noise Characteristics of the Pantograph of the High-speed Train

The high-speed-train pantograph is a complex structure that consists of different rod-shaped and rectangular surfaces. Flow phenomena around the pantograph are complicated and can cause a large proportion of aerodynamic noise, which is one of the main aerodynamic noise sources of a high-speed train. Therefore, better understanding of aerodynamic noise characteristics is needed. In this study, the large eddy simulation (LES) coupled with the acoustic finite element method (FEM) is applied to analyze aerodynamic noise characteristics of a high-speed train with a pantograph installed on different configurations of the roof base, i.e. flush and sunken surfaces. Numerical results are presented in terms of acoustic pressure spectra and distributions of aerodynamic noise in near-field and far-field regions under up- and down-pantograph as well as flushed and sunken pantograph base conditions. The results show that the pantograph with the sunken base configuration provides better aerodynamic noise performances when compared to that with the flush base configuration. The noise induced by the down-pantograph is higher than that by the up-pantograph under the same condition under the pantograph shape and opening direction selected in this paper. The results also indicate that, in general, the directivity of the noise induced by the down-pantograph with sunken base configuration is slighter than that with the flush configuration. However, for the up-pantograph, the directivity is close to each other in Y-Z or X-Z plane whether it is under flush or sunken roof base condition. However, the sunken installation is still conducive to the noise environment on both sides of the track.

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Reduction of Aerodynamic Noise of High-speed Train Pantograph

Journal of Mechanical Engineering ◽

10.3901/jme.2017.06.094 ◽

2017 ◽

Vol 53 (6) ◽

pp. 94

Author(s):

Yadong ZHANG

Keyword(s):

High Speed ◽

Aerodynamic Noise ◽

High Speed Train

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

Shock and Vibration ◽

10.1155/2018/5319460 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13 ◽

Cited By ~ 3

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.

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The Application of Numerical Simulation Technology in the External Aerodynamic Noise Field of High-Speed Train

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.101-102.197 ◽

2011 ◽

Vol 101-102 ◽

pp. 197-201 ◽

Cited By ~ 2

Author(s):

Zhen Gyu Zheng ◽

Ren Xian Li

Keyword(s):

Numerical Simulation ◽

Boundary Condition ◽

High Speed ◽

Aerodynamic Noise ◽

Dipole Source ◽

Center Line ◽

High Speed Train ◽

Noise Field ◽

Computational Fluid Dynamics Cfd ◽

Flow Pressure

This paper utilized the Boundary Element Method (BEM) combined with the Computational Fluid Dynamics (CFD) based on Lighthill’s analogy in the high-speed train model, and converted the fluctuating flow pressure near the vehicle’s surface into the dipole source boundary condition in acoustics grid, eventually succeeded in completing the numerical simulation of aerodynamic noise field outside the high-speed train by introducing the dipole source boundary condition into the train BEM model. The results show that the main aerodynamic noise controlling area is 15-20 meters away from the track center line in the horizontal direction, and the Sound Press Level (SPL) is 63-72dB.

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A25 Sound characteristic of aerodynamic noise generated from pantograph on a high-speed train

The Proceedings of Conference of Kyushu Branch ◽

10.1299/jsmekyushu.2008.61.19 ◽

2008 ◽

Vol 2008.61 (0) ◽

pp. 19-20

Author(s):

Yuki IJICHI ◽

Daiki UENO ◽

Taizo MORINO ◽

Nobuaki KONDOH ◽

Toshiyuki AOKI

Keyword(s):

High Speed ◽

Aerodynamic Noise ◽

High Speed Train

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E20 Sound characteristic of aerodynamic noise generated from pantograph on a high-speed train

The Proceedings of Conference of Kyushu Branch ◽

10.1299/jsmekyushu.2008.201 ◽

2008 ◽

Vol 2008 (0) ◽

pp. 201-202

Author(s):

Yuki IJICHI ◽

Tsutomu ODO ◽

Nobuaki KONDOH ◽

Toshiyuki AOKI

Keyword(s):

High Speed ◽

Aerodynamic Noise ◽

High Speed Train

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Numerical Analysis of the Surface Aerodynamic Noise of the CRH3 High Speed Train

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1044-1045.643 ◽

2014 ◽

Vol 1044-1045 ◽

pp. 643-649

Author(s):

Ji Zhou Liu ◽

Ren Xian Li ◽

Peng Xiang Cui

Keyword(s):

High Speed ◽

Noise Source ◽

Radiation Power ◽

Spectral Characteristics ◽

Radiation Energy ◽

Simulation Method ◽

Acoustic Power ◽

Broadband Noise ◽

Aerodynamic Noise ◽

High Speed Train

For high speed trains running at 300km/h or more, the aerodynamic noise becomes the primary noise source. A good knowledge of the location, spectral characteristics and propagation behavior of the noise source and the corresponding methods to reduce the effect of the aerodynamic noise are of crucial necessity during the design process of the high speed train. Based on the Lighthill Analogy, the pressure fluctuation of air at the surface of the train is acquired by simulating the flow field of a CRH3 high speed train running at 200 km/h, 300 km/h, 400 km/h and 500km/h by means of large eddy simulation method. By Fourier transformation, the distribution and the spectral characteristics of the surface acoustic dipole sources are obtained. The analysis of the results shows that the aerodynamic noise of the high speed train is a broadband noise with a strong radiation power band from 50Hz to 1000Hz. The dipole acoustic power calculated by statistically averaged on train surface is found to be proportional to the sixth power of running speed of the high speed train. The first and second bogie, the inter-car gap, the air deflector of the power train and the train nose of the last wagon are the main noise sources that contain high radiation energy.

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Research on Aerodynamic Noise Reduction for High-Speed Trains

Shock and Vibration ◽

10.1155/2016/6031893 ◽

2016 ◽

Vol 2016 ◽

pp. 1-21 ◽

Cited By ~ 7

Author(s):

Yadong Zhang ◽

Jiye Zhang ◽

Tian Li ◽

Liang Zhang ◽

Weihua Zhang

Keyword(s):

Noise Reduction ◽

High Speed ◽

Low Noise ◽

Broadband Noise ◽

Full Scale ◽

Noise Model ◽

Aerodynamic Noise ◽

High Speed Train ◽

Detached Eddy Simulation ◽

Noise Sources

A broadband noise source model based on Lighthill’s acoustic theory was used to perform numerical simulations of the aerodynamic noise sources for a high-speed train. The near-field unsteady flow around a high-speed train was analysed based on a delayed detached-eddy simulation (DDES) using the finite volume method with high-order difference schemes. The far-field aerodynamic noise from a high-speed train was predicted using a computational fluid dynamics (CFD)/Ffowcs Williams-Hawkings (FW-H) acoustic analogy. An analysis of noise reduction methods based on the main noise sources was performed. An aerodynamic noise model for a full-scale high-speed train, including three coaches with six bogies, two inter-coach spacings, two windscreen wipers, and two pantographs, was established. Several low-noise design improvements for the high-speed train were identified, based primarily on the main noise sources; these improvements included the choice of the knuckle-downstream or knuckle-upstream pantograph orientation as well as different pantograph fairing structures, pantograph fairing installation positions, pantograph lifting configurations, inter-coach spacings, and bogie skirt boards. Based on the analysis, we designed a low-noise structure for a full-scale high-speed train with an average sound pressure level (SPL) 3.2 dB(A) lower than that of the original train. Thus, the noise reduction design goal was achieved. In addition, the accuracy of the aerodynamic noise calculation method was demonstrated via experimental wind tunnel tests.

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Numerical Modeling and Investigation on Aerodynamic Noise Characteristics of Pantographs in High-Speed Trains

Complexity ◽

10.1155/2018/6932596 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 5

Author(s):

Xiaoqi Sun ◽

Han Xiao

Keyword(s):

High Frequency ◽

High Speed ◽

Sound Pressure ◽

Noise Source ◽

Flow Fields ◽

Aerodynamic Noise ◽

Far Field ◽

Frequency Bands ◽

Noise Characteristics ◽

High Speed Trains

Pantographs are important devices on high-speed trains. When a train runs at a high speed, concave and convex parts of the train cause serious airflow disturbances and result in flow separation, eddy shedding, and breakdown. A strong fluctuation pressure field will be caused and transformed into aerodynamic noises. When high-speed trains reach 300 km/h, aerodynamic noises become the main noise source. Aerodynamic noises of pantographs occupy a large proportion in far-field aerodynamic noises of the whole train. Therefore, the problem of aerodynamic noises for pantographs is outstanding among many aerodynamics problems. This paper applies Detached Eddy Simulation (DES) to conducting numerical simulations of flow fields around pantographs of high-speed trains which run in the open air. Time-domain characteristics, frequency-domain characteristics, and unsteady flow fields of aerodynamic noises for pantographs are obtained. The acoustic boundary element method is used to study noise radiation characteristics of pantographs. Results indicate that eddies with different rotation directions and different scales are in regions such as pantograph heads, hinge joints, bottom frames, and insulators, while larger eddies are on pantograph heads and bottom frames. These eddies affect fluctuation pressures of pantographs to form aerodynamic noise sources. Slide plates, pantograph heads, balance rods, insulators, bottom frames, and push rods are the main aerodynamic noise source of pantographs. Radiated energies of pantographs are mainly in mid-frequency and high-frequency bands. In high-frequency bands, the far-field aerodynamic noise of pantographs is mainly contributed by the pantograph head. Single-frequency noises are in the far-field aerodynamic noise of pantographs, where main frequencies are 293 Hz, 586 Hz, 880 Hz, and 1173 Hz. The farther the observed point is from the noise source, the faster the sound pressure attenuation will be. When the distance of two adjacent observed points is increased by double, the attenuation amplitude of sound pressure levels for pantographs is around 6.6 dB.

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