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.

Research on Model of Noise Prediction of High-Speed Train by SEA Method

2012 ◽  
Author(s):  
Lifang Yang ◽  
Xiaowei He ◽  
Fanyu Meng
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Noise Analysis ◽  
Input Power ◽  
Aerodynamic Noise ◽  
Noise Prediction ◽  
High Speed Train ◽  
Small Noise ◽  
High Speed Trains ◽  
Calculation Results

China’s rapid development of high-speed train has been in the research spotlight over the years; this paper presents a method to predict the transmission of aerodynamic noise and rail noise inside train compartments for high-speed trains operating at speeds larger than 200 km/h. The numerical tool could be used in parameter studies for noise control. In order to develop the noise prediction model of high speed train, the noise source of high-speed train is analyzed. Based on the noise analysis, the SEA model is built. Due to the small noise difference in one train car, the SEA model is divided into head cab, head passenger cab and middle car three parts. Combined with the finite and boundary element method, the input power and SEA parameters are researched and calculated. In the end of the paper, the results of SEA noise predicting model are compared with theoretical calculation results in order to verify the engineering use.

Psychoacoustic Properties Analysis on Interior Noise of High-Speed Trains

2013 ◽  
Vol 712-715 ◽  
pp. 2865-2869
Author(s):  
Li Fang Yang ◽  
Fan Yu Meng ◽  
Bo Kang
Keyword(s):  
Calculation Method ◽  
High Speed ◽  
Interior Noise ◽  
High Speed Train ◽  
High Speed Trains ◽  
Noise Evaluation ◽  
And Control

In order to analyze the noise properties and promote the sound comfort of the high-speed train, the noise samples are collected in passengers cars, dining cars and car joint parts at different speeds. By means of 18 sound samples, the psychoacoustic parameters of the high-speed train are discussed. Before calculation of other psychoacoustic properties, the calculation method of loudness must be properly chosen through analysis of all loudness calculation method. In the paper, the Filter/ISO 532B method is selected to obtain the loudness of the high-speed train and based on the loudness; other psychoacoustic properties are obtained and analyzed. The discussion of psychoacoustic properties is the basis of further noise evaluation and control of high-speed trains.

scholarly journals Aerodynamic Noise Separation of an EMU Trailer Bogie Area Using Train Operation Tests

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Leiming Song ◽  
Hao Chen ◽  
Baochuan Li
Keyword(s):  
Transfer Coefficient ◽  
High Speed ◽  
Noise Analysis ◽  
Central Area ◽  
Aerodynamic Noise ◽  
Frequency Noise ◽  
High Speed Train ◽  
Radiated Noise ◽  
High Speed Trains ◽  
Train Operation

The operation transfer path analysis (OTPA) technique was used to measure the vibration and noise transfer coefficient functions of wheel-rail noise and radiated noise from an electric multiple unit (EMU) train (high-speed train in China) trailer bogie structure to the central area of the trailer bogie for a train running at speeds of 0–5 km/h. By applying these transfer coefficient functions to the noise analysis of high-speed train operation, the contributions of wheel-rail noise and frame-radiated noise to the noise of the bogie area at high speeds are obtained, and the aerodynamic noise is separated from the total noise, providing a reference for vibration damping and noise reduction in high-speed trains. Analysis of test data shows that, in the central area of the trailer bogie of high-speed trains, the low-frequency noise mainly comes from the structural radiated noise of the bogie, and the mid- to high-frequency noise is primarily due to aerodynamic noise. In addition, when an EMU train operates at speeds below 250 km/h, the noise in the central area of the trailer bogie is primarily caused by the structural radiated noise. When the operating speed is higher than 250 km/h, the noise in the central area of the trailer bogie is mainly due to aerodynamic noise, and the aerodynamic noise contribution increases with increase in speed.

scholarly journals Noise reduction in high-speed train gangways using fairings and side barriers

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402094613
Author(s):  
Hee-Min Noh
Keyword(s):  
Noise Reduction ◽  
High Speed ◽  
Noise Analysis ◽  
Low Frequency ◽  
Frequency Region ◽  
Interior Noise ◽  
High Speed Train ◽  
Noise Component ◽  
Flow Noise ◽  
Reduction Methods

Interior noise in high-speed trains creates passenger discomfort and fatigue. In particular, the noise generated around the gangway between carriages tends to be easily transmitted to the passenger spaces due to the large noise component in the low-frequency region. In addition, the noise from the between-cars space around the gangway exterior tends to increase significantly when the high-speed train is travelling inside a tunnel. Therefore, this study analyses the cause of the noise generated in the gangways and identifies an effective method for reducing it. First, the mechanism for noise generation around the gangways was determined by computational flow noise analysis using a simple two-dimensional cavity model. From this simulation, it was confirmed that noise is generated when air flow enters the cavity. To investigate the influence of noise reduction in the between-cars section, blocking the airflow indirectly by installing fairings or directly by using side barriers was proposed. These noise reduction methods were examined by flow noise analysis, and then applied to an actual high-speed train. The interior noise was measured, and the results show that the use of side barriers was effective in reducing interior noise by 10 dB or more. In particular, a high noise reduction effect was exhibited in the low-frequency region. Therefore, this study verifies that directly blocking the inflow into the between-cars section is an effective noise reduction method.

scholarly journals An investigation into high-speed train interior noise with operational transfer path analysis method

2021 ◽  
Author(s):  
Muxiao Li ◽  
Ziwei Zhu ◽  
Tiesong Deng ◽  
Xiaozhen Sheng
Keyword(s):  
Sound Source ◽  
Reference Point ◽  
Source Identification ◽  
High Speed ◽  
Interior Noise ◽  
Target Point ◽  
High Speed Train ◽  
Transfer Path ◽  
Sound Source Identification ◽  
Transfer Path Analysis

AbstractPassengers' demands for riding comfort have been getting higher and higher as the high-speed railway develops. Scientific methods to analyze the interior noise of the high-speed train are needed and the operational transfer path analysis (OTPA) method provides a theoretical basis and guidance for the noise control of the train and overcomes the shortcomings of the traditional method, which has high test efficiency and can be carried out during the working state of the targeted machine. The OTPA model is established from the aspects of "path reference point-target point" and "sound source reference point-target point". As for the mechanism of the noise transmission path, an assumption is made that the direct sound propagation is ignored, and the symmetric sound source and the symmetric path are merged. Using the operational test data and the OTPA method, combined with the results of spherical array sound source identification, the path contribution and sound source contribution of the interior noise are analyzed, respectively, from aspects of the total value and spectrum. The results show that the OTPA conforms to the calculation results of the spherical array sound source identification. At low speed, the contribution of the floor path and the contribution of the bogie sources are dominant. When the speed is greater than 300 km/h, the contribution of the roof path is dominant. Moreover, for the carriage with a pantograph, the lifted pantograph is an obvious source. The noise from the exterior sources of the train transfer into the interior mainly through the form of structural excitation, and the contribution of air excitation is non-significant. Certain analyses of train parts provide guides for the interior noise control.

Comparative study on the use of acoustic emission and vibration analyses for the bearing fault diagnosis of high-speed trains

2021 ◽  
pp. 147592172110360
Author(s):  
Dongming Hou ◽  
Hongyuan Qi ◽  
Honglin Luo ◽  
Cuiping Wang ◽  
Jiangtian Yang
Keyword(s):  
Acoustic Emission ◽  
Fault Diagnosis ◽  
High Speed ◽  
High Speed Train ◽  
Signal Attenuation ◽  
Transmission Path ◽  
Bearing Fault Diagnosis ◽  
Operation Conditions ◽  
Fault Features ◽  
High Speed Trains

A wheel set bearing is an important supporting component of a high-speed train. Its quality and performance directly determine the overall safety of the train. Therefore, monitoring a wheel set bearing’s conditions for an early fault diagnosis is vital to ensure the safe operation of high-speed trains. However, the collected signals are often contaminated by environmental noise, transmission path, and signal attenuation because of the complexity of high-speed train systems and poor operation conditions, making it difficult to extract the early fault features of the wheel set bearing accurately. Vibration monitoring is most widely used for bearing fault diagnosis, with the acoustic emission (AE) technology emerging as a powerful tool. This article reports a comparison between vibration and AE technology in terms of their applicability for diagnosing naturally degraded wheel set bearings. In addition, a novel fault diagnosis method based on the optimized maximum second-order cyclostationarity blind deconvolution (CYCBD) and chirp Z-transform (CZT) is proposed to diagnose early composite fault defects in a wheel set bearing. The optimization CYCBD is adopted to enhance the fault-induced impact response and eliminate the interference of environmental noise, transmission path, and signal attenuation. CZT is used to improve the frequency resolution and match the fault features accurately under a limited data length condition. Moreover, the efficiency of the proposed method is verified by the simulated bearing signal and the real datasets. The results show that the proposed method is effective in the detection of wheel set bearing faults compared with the minimum entropy deconvolution (MED) and maximum correlated kurtosis deconvolution (MCKD) methods. This research is also the first to compare the effectiveness of applying AE and vibration technologies to diagnose a naturally degraded high-speed train bearing, particularly close to actual line operation conditions.

scholarly journals A Study on the Energy-Harvesting Device with a Magnetic Spring for Improved Durability in High-Speed Trains

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 830
Author(s):  
Jaehoon Kim
Keyword(s):  
Energy Harvesting ◽  
High Speed ◽  
Permanent Magnets ◽  
Critical Issue ◽  
Sensor Nodes ◽  
High Speed Train ◽  
Vibration Energy Harvesting ◽  
Magnetic Spring ◽  
High Speed Trains ◽  
Energy Harvesting Devices

Durability is a critical issue concerning energy-harvesting devices. Despite the energy-harvesting device’s excellent performance, moving components, such as the metal spring, can be damaged during operation. To solve the durability problem of the metal spring in a vibration-energy-harvesting (VEH) device, this study applied a non-contact magnetic spring to a VEH device using the repulsive force of permanent magnets. A laboratory experiment was conducted to determine the potential energy-harvesting power using the magnetic spring VEH device. In addition, the characteristics of the generated power were studied using the magnetic spring VEH device in a high-speed train traveling at 300 km/h. Through the high-speed train experiment, the power generated by both the metal spring VEH device and magnetic spring VEH device was measured, and the performance characteristics required for a power source for wireless sensor nodes in high-speed trains are discussed.

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.

Effect of Pantograph and Bogie on Interior Noise of High-Speed Train in Tunnel

2013 ◽  
Vol 664 ◽  
pp. 191-196
Author(s):  
You Gang Xiao ◽  
Yu Shi
Keyword(s):  
High Speed ◽  
Sound Pressure ◽  
Broad Band ◽  
Pressure Level ◽  
Channel Noise ◽  
High Speed Train ◽  
Noise Sources ◽  
Vehicle Noise ◽  
Measurement And Analysis ◽  
Analysis System

For clarifying the noise in tunnel affected by pantograph and bogie, which are the most important noise sources, the noises near pantograph and bogie in a high-speed train were tested by multi-channel noise measurement and analysis system in tunnel, and compared with those measured outside the High-speed train and on an open field. The results show that the interior vehicle noise is spatially non-homogeneous in the whole carriage, the larger sound pressure level (SPL) near pantograph are next to ceiling, and near bogie next to floor. The noise spectra show a broad band feature, and dominated by the frequency contents among 100Hz-2kHz, so the countermeasures against noise should be within these range.

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