Influence of the Friction Block Shape and Installation Angle of High-Speed Train Brakes on Brake Noise

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Xin Quan ◽  
Jiliang Mo ◽  
Bo Huang ◽  
Bin Tang ◽  
Huajiang Ouyang ◽  
...  
Keyword(s):  
Contact Pressure ◽  
High Speed ◽  
Sound Pressure ◽  
Dominant Frequency ◽  
Small Scale ◽  
Installation Angle ◽  
High Speed Trains ◽  
Different Shapes ◽  
Brake Dynamometer ◽  
Brake Noise

Abstract In this study, experiments are conducted to evaluate the effects of friction block shapes and installation angles on the brake noise of high-speed trains on a customized small-scale brake dynamometer. Friction blocks in three different shapes (circle, triangle, and hexagon) and triangular/hexagonal friction blocks at different installation angles are used in the tests. The results indicate that the circular and triangular blocks exhibit low sound pressure with multiple harmonics, whereas the hexagonal friction block produces the highest sound pressure with a single dominant frequency. This difference is attributed to the high contact pressure and severe wear on the surface of the hexagonal friction block. Differences in the installation angle of the triangular/hexagonal friction blocks affect wear debris behavior, distribution of contact pressure, and contact state of the friction interface, consequently influencing noise performance.

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

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
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.

Assessment of fire behaviour of high-speed trains' interior materials: small-scale and full-scale fire tests

2013 ◽  
Vol 38 (7) ◽  
pp. 725-743 ◽  
Author(s):  
Jorge A. Capote ◽  
José A. Jimenez ◽  
Daniel Alvear ◽  
Julio Alvarez ◽  
Orlando Abreu ◽  
...  
Keyword(s):  
High Speed ◽  
Full Scale ◽  
Small Scale ◽  
Fire Tests ◽  
Fire Behaviour ◽  
High Speed Trains

scholarly journals A Systematic Approach to Identify Sources of Abnormal Interior Noise for a High-Speed Train

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jie Zhang ◽  
Xinbiao Xiao ◽  
Xiaozhen Sheng ◽  
Zhihui Li ◽  
Xuesong Jin
Keyword(s):  
High Speed ◽  
Sound Pressure ◽  
Systematic Approach ◽  
Noise Analysis ◽  
Interior Noise ◽  
Sound Insulation ◽  
High Speed Train ◽  
Main Contributor ◽  
Vibration Data ◽  
High Speed Trains

A systematic approach to identify sources of abnormal interior noise occurring in a high-speed train is presented and applied in this paper to resolve a particular noise issue. This approach is developed based on a number of previous dealings with similar noise problems. The particular noise issue occurs in a Chinese high-speed train. It is measured that there is a difference of 7 dB(A) in overall Sound Pressure Level (SPL) between two nominally identical VIP cabins at 250 km/h. The systematic approach is applied to identify the root cause of the 7 dB(A) difference. Well planned measurements are performed in both the VIP cabins. Sound pressure contributions, either in terms of frequency band or in terms of facing area, are analyzed. Order analysis is also carried out. Based on these analyses, it is found that the problematic frequency is the sleeper passing frequency of the train, and an area on the roof contributes the most. In order to determine what causes that area to be the main contributor without disassembling the structure of the roof, measured noise and vibration data for different train speeds are further analyzed. It is then reasoned that roof is the main contributor caused by sound pressure behind the panel. Up to this point, panels of the roof are removed, revealing that a hole of 300 cm2 for running cables is presented behind the red area without proper sound insulation. This study can provide a basis for abnormal interior noise analysis and control of high-speed trains.

Analysis of the near-field and far-field sound pressure generated by high-speed trains pantograph system

2020 ◽  
Vol 169 ◽  
pp. 107506
Author(s):  
Yue-ying Zhao ◽  
Zhi-gang Yang ◽  
Qi-liang Li ◽  
Chao Xia
Keyword(s):  
High Speed ◽  
Sound Pressure ◽  
Near Field ◽  
Far Field ◽  
High Speed Trains ◽  
Field Sound

Experimental investigation of the squeal characteristics in railway disc brakes

2018 ◽  
Vol 232 (11) ◽  
pp. 1437-1449 ◽  
Author(s):  
B Tang ◽  
JL Mo ◽  
X Zhang ◽  
Q Zhang ◽  
MH Zhu ◽  
...  
Keyword(s):  
Sound Pressure ◽  
Brake System ◽  
Small Scale ◽  
Noise Characteristics ◽  
Disc Brakes ◽  
Disc Rotation ◽  
Disc Rotation Speed ◽  
Brake Dynamometer ◽  
Squeal Noise

In this study, a bespoke small-scale brake dynamometer was developed to simulate the braking conditions of a railway disc brake system. Braking squeal experiments were performed with this brake dynamometer at different braking pressures and disc rotation speeds, and the influence of these braking parameters on the generation and characterization of the squeal noise was evaluated and discussed. The obtained results show that both the braking pressure and the disc rotation speed have a significant influence on the generation and evolution of the squeal noise. Higher rotation speeds are found to result in higher sound pressures and more complicated squeal noise spectra, except at a particular braking pressure, for which the highest sound pressure level is found at various disc rotation speeds. This phenomenon indicates that a combination of specific braking parameters may lead to a strong instability of the brake system and consequently to squeal noise. Additionally, a possible correlation of the squeal noise characteristics with the pressure distribution at the braking interface was found and discussed.

Battery Self-Traction System for High-Speed Trains

2020 ◽  
Vol 140 (5) ◽  
pp. 349-355
Author(s):  
Hirokazu Kato ◽  
Kenji Sato
Keyword(s):  
High Speed ◽  
High Speed Trains ◽  
Traction System
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