High-speed Train Noise Research Articles

고속열차의 바람소리에 따른 실내소음 예측을 위한 표면압력 섭동의 파수-주파수 분석

고속열차의 바람소리에 따른 실내소음 예측을 위한 표면압력 섭동의 파수-주파수 분석

A method to evaluate the aeroacoustic bogie noise of Shinkansen high-speed trains by considering the acoustic field

A method to evaluate the aeroacoustic bogie noise of Shinkansen high-speed trains by considering the acoustic field

Experimental and Numerical Investigation on the External Aerodynamic Noise of High-Speed Train

Experimental and Numerical Investigation on the External Aerodynamic Noise of High-Speed Train

Aerodynamic Noise Simulation and Quadrupole Noise Problem of 600km/h High-Speed Train

The quadrupole aerodynamic noise is a difficult problem in numerical simulation of the aerodynamic noise. The Kirchhoff-Ffowcs Williams and Hawkings (K-FWH) equation method and the three-dimensional compressible Large Eddy Simulation (LES) method are adopted in this manuscript for aerodynamic noise accuracy simulation of 600km/h high-speed train. The influence of different distributions of penetrable integral surfaces on the results of far-field aerodynamic noise is discussed. The optimum combination form of penetrable integral surfaces is obtained. The aerodynamic noise of high-speed train considering quadrupole can be calculated efficiently and accurately by using the upstream body surface and wake area penetrable integral surface as sound source surface. The wake area penetrable integral surface should contain the main vorticity structure of the wake as far as possible and the surface vorticity amplitude should be insignificant. The contribution rate of the dipole and quadrupole to the total aerodynamic noise energy of high-speed train is different. The aerodynamic noise energy of the upstream measurement points is mainly dipole aerodynamic noise energy, while that of the downstream measurement points is mainly dipole and quadrupole noise energy. The method proposed in this manuscript is of great significance in the aerodynamic noise numerical simulation of 600km/h high-speed train.

Measurement of aerodynamic bogie noise of high-speed trains by wind tunnel test and numerical analysis

Measurement of aerodynamic bogie noise of high-speed trains by wind tunnel test and numerical analysis

Multi-objective optimization for the aerodynamic noise of the high-speed train in the near and far field based on the improved NSGA-II algorithm

With the increased running speed of trains, the aerodynamic noise of trains becomes increasingly obvious. Reducing aerodynamic noises has become one of keys to controlling the noise of high-speed trains. This paper conducted a numerical simulation on the aerodynamic noise of head of the high-speed train. Firstly, this paper established a mathematical-physical model for the three-dimensional turbulent flow field of a high-speed train, adopted standard k-ε equation turbulent model and broadband noise source model to compute the aerodynamic noise sources of the high-speed train and applied three-dimensional transient large eddy simulation (LES) to compute the external unsteady flow field of the high-speed train after obtaining noise sources. Based on the unsteady flow field, then this paper applied FW-H equations to compute the far-field aerodynamic noise of the high-speed train. After obtaining the unsteady fluctuation pressure on the surface of the train, this paper computed the radiation characteristics of aerodynamic noises around the high-speed train based on the boundary element method (BEM). Researched results showed: The main aerodynamic noise sources of the high-speed train were at the nose tip of head train; fluid separation and recombination were main reasons for the aerodynamic noise of the high-speed train; vortexes in the position of head train were striped and horseshoe-shaped or hairpin vortexes were mainly in the area of tail train; in addition, vortexes were symmetrically distributed along the longitudinal symmetry plane of train; dipole noises were mainly distributed in the area of head train, whose main energy was decreased with the increased frequency; the quadrupole noise of aerodynamic noises of the high-speed train was mainly distributed in the wake flow area of tail train; when the high-speed train ran at the speed of 300 km/h, the maximum sound pressure level of far-field observation points was 76.8 dB; additionally, aerodynamic noises in the far field were mainly a broadband noise, whose main energy was within the frequency range of 1250 Hz to 3150 Hz. Finally, the improved NSGA-II algorithm was used to conduct a multi-objective optimization for the head shape. The aerodynamic drag of the high-speed train could be most reduced by 6.74 %, and the dipole aerodynamic noise source could be most reduced by 8.34 dB. The improved NSGA-II algorithm has an obvious effect on the multi-objective optimization of the head shape.

Numerical study on the aerodynamic noise characteristics of CRH2 high-speed trains

The aerodynamic noise of high-speed trains not only causes interior noise pollution and reduces the comfort of passengers, but also seriously affects the normal life of residents. With the increase of running speed of trains, aerodynamic noises will be more than wheel-rail noises and become the main noise source of high-speed trains. This paper established a computational model for the aerodynamic noise of a CRH2 high-speed train with 3-train formation including 3 train bodies and 6 bogies, adopted the detached eddy simulation (DES) to conduct numerical simulation for the flow field around the high-speed train, applied Ffowcs Williams-Hawkings acoustic model to conduct unsteady computation for the aerodynamic noise of high-speed trains, and analyzed the far-field aerodynamic noise characteristics of high-speed trains. Studied results showed: The main energy of the complete train was mainly within the range of 613 Hz-2500 Hz when the high-speed train ran at the speed of 350 km/h. In the whole frequency domain, it was a broadband noise. Regarding the longitudinal observation point which was 25 m away from the center line of track and 6m away from the nose tip of head train, the sound pressure level of total noises reached the maximum value 88.9 dBA. The maximum sound pressure level of the noise observation point which was 7.5 m away from the center line of track was around the first bogie of head train. Various components made different contributions to the aerodynamic noise of the complete train, and the order was head train, mid train, bogie system (6 bogies) and tail train. The first bogie of head train made the greatest contribution to bogie system and was the main aerodynamic noise source of the complete train.

Experimental research and numerical analysis on vibroacoustic characteristics of the laminated composite plate and its application in high-speed trains

This paper firstly used the finite element method to study the impact of air coupling on the structural radiation noise of thin plates and conducted a comparative analysis on the vibration noise of thin plates in the water and air. Results showed that coupling effect and medium property had an obvious influence on the radiation noise of thin plates, and these factors must be considered. Secondly, this paper proposed laminated plates based on the single-layered thin plate. The related experiment of laminated plates was conducted and compared with the computational result to verify its reliability. As an important parameter of laminated plates, laying angle can change the structural stiffness of laminated plates and mechanical properties. Therefore, based on the verified computation model, this paper studied the radiation noise of laminated plates through changing the laying angle of laminated plates, improved the vibration noise of laminated plates through applying control forces. As a result, a laminated plate with the optimal performance can be obtained. Finally, laminated composite plates were applied to the inner surface of panels which had made greater acoustic contributions to high-speed trains and controlled the vibration noise of high-speed trains through applying control forces. Results showed that the peak noise of high-speed trains was obviously improved at multiple frequencies and total sound power levels reduced by 23.1 dB.

Research on the distribution of aerodynamic noises of high-speed trains

This paper established a computational model for the aerodynamic noise of a high-speed train with 3-train formation including 3 bodies, 6 bogies, 2 windshields and 1 pantograph system. Based on Lighthill acoustic theory, this paper adopted large eddy simulation (LES) and FW-H model to conduct numerical simulation for the aerodynamic noise of high-speed trains and analyzed the distribution of aerodynamic flow behavior and noises of the whole train. Researched results showed that the main aerodynamic noise sources of high-speed trains were in pantograph, pantograph region, streamlined region of head train, bogies, bogie region, windshield region, air conditioning and other regions. Pantograph head, junction of upper arm and lower arm, and chassis region were main aerodynamic noise sources of pantograph. Compared with other 5 bogies, bogie at the first end of head train was main aerodynamic noise source. In addition, vortex shedding and fluid separation were main reasons for the aerodynamic noise of high-speed trains. When the high-speed train ran at the speed of 300 km/h and 400 km/h, the main energy of the whole train focused on the range of 1000 Hz-4000 Hz. Aerodynamic noises were broadband noises in the analyzed frequency domain. At the longitudinal observation point which was 25 m away from the center line of track and 25 m away from the nose tip of head train, the total noise sound pressure level reached up to maximum values 96.5 dBA and 101.4 dBA, respectively. Compared with inflow, wake flow had a greater influence on the aerodynamic noise around high-speed trains. The main radiation direction of pantograph aerodynamic noises was the left and right sides of pantograph head. In addition, the main radiation energy of pantograph aerodynamic noises was in mid-high frequency. In the part of high frequency, pantograph head made the greatest contribution to aerodynamic noises in the far field.

The Problem of High-Speed Railway Noise Prediction and Reduction

In view of the rapid high-speed railway transport development in the world, the question of ecological safety of the people living in the areas adjacent to transport infrastructure networks, including physical factors compliance, becomes crucial. The article introduces problems of high-speed railway noise control and prediction (with train speed from 250 to 400 km\\h), calculation methods for determining high-speed train noise characteristics; comparison of the calculation and experimental results is made. The article describes main ways of high-speed train noise reduction, in the noise source in particular, such as installing small local noise barriers and aerodynamic streamlining of the rolling stock and its separate elements (pantograph, etc.), implemented in China, Japan, France, German, South Korea and other countries. The article also considers efficiency of the main practically applied noise mitigation measures.

종합검측차 검측모듈의 차상노이즈 분석

Abstract –Recently, various monitoring systems have been proposed to detect interaction performance between trains and infrastructure, as well as, various techniques to improve the accuracy and performance of such inspection equipment in high speeds. Especially, it is important to predict electric noise of high speed trains due to its effect on detection system accuracy. In this paper, we analyze various types of electrical noise in electric vehicles to improve the accuracy of the detection module of the inspection car. In detail, analysis of electric noise of high speed railway is performed as a function of speed based on field tests that were carried out by HEMU-430X (Highspeed Eletric Multiple Unit - 430 km/h eXperiment). Key Words : Inspection car, Railway infrastructure, Maintenance equipment† Corresponding Author : School of Electronic and Electrical Engineering, Sungkyunkwan University, Korea.E-mail: jaehyeong@skku.edu* Dept. of High-Speed Railroad Research Center, Korea Railroad Research Institute, Korea** School of Electrical Engineering, Korea University, Korea*** School of Electronic and Electrical Engineering, Sungkyunkwa n University, Korea.Received : March 27, 2015; Accepted : April 29, 2015

Effect of the first two wheelset bending modes on wheel-rail contact behavior

This work presents a detailed investigation conducted into the relationships between wheel polygonal wear and wheel/rail noise, and the interior noise of high-speed trains through extensive experiments and numerical simulations. The field experiments include roundness measurement and characteristics analysis of the high-speed wheels in service, and analysis on the effect of re-profiling on the interior noise of the high-speed coach. The experimental analysis shows that wheel polygonal wear has a great impact on wheel/rail noise and interior noise. In the numerical simulation, the model of high-speed wheel/rail noise caused by the uneven wheel wear is developed by means of the high-speed wheel-track noise software (HWTNS). The calculation model of the interior noise of a high-speed coach is developed based on the hybrid of the finite element method and the statistic energy analysis (FE-SEA). The numerical simulation analyses the effect of the polygonal wear characteristics, such as roughness level, polygon order (or wavelength), and polygon phase, on wheel/rail noise and interior noise of a high-speed coach. The numerical results show that different polygon order with nearly the same roughness levels can cause different wheel/rail noises and interior noises. The polygon with a higher roughness level can cause a larger wheel/rail noise and a larger interior noise. The combination of different polygon phases can make a different wheel circle diameter difference due to wear, but its effect on the interior noise level is not great. This study can provide a basis for improving the criteria for high-speed wheel re-profiling of China’s high-speed trains.

Numerical Analysis of the Surface Aerodynamic Noise of the CRH3 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.

터널 주행을 고려한 고속열차의 실내소음 특성 평가

conducted. In-situ measurements were conducted to investigate the noise characteristics in high-speed trains such as KTX and KTX-Sancheon. Binaural microphones and spherical microphone were adopted to record and evaluate the spectral characteristics and noise incidence characteristics at the seats in the passenger cars. Environmental elements were also recorded during the noise measurements using a camcorder and GPS application. In addition, auditory tests were conducted to investigate annoyance of interior noise of high-speed trains. Based on the objective measure and subjective responses on interior noise, statistical analysis such as correlation and regression analyses were carried out. From the results perception models for evaluating the interior noise of high-speed train were derived.

Bionic Design of Koch Snowflake Surface Texture and Its Effects on Air Frictional Noise of High Speed Train

In order to reduce the air frictional noise at the air-carriage interface of high speed train, a Koch type snowflake surface structure is designed to simulate the fractal structure of snowflake and analyzed with the theory of computational fluid dynamics(CFD) and the method of bionic design for the surface of high speed train. The compressible N-S equation is solved using unstructured hybrid grid and k ?? model and the noise distribution is solved based on broadband noise source. Simulation results demonstrate that the air frictional noise is greatly reduced because of the secondary vortex generated in the Koch snowflake like surface structure. A kind of multi scale surface structure consists of Koch snowflake cells on two scales and a sort of compound surface texture combining cells of Koch snowflake and circular dents are designed in order to further explore the influence of surface texture on the decrease of the noise of high speed train; that multi scale surface texture is better than single texture but compound surface texture is worse than the better one of the single texture in reduction of the air frictional noise, which provide an effective guidance for the study of reducing the air frictional noise of high speed train.

Study on High-speed Train Abnormal Interior Vibration and Noise Related to Wheel Roughness

Based on field tests of high-speed coaches X and Y, the characteristics and mechanisms of the abnormal interior noise and vibration occurred in the type X coach are investigated. In the field tests, the test coaches are running at the same operation speed and similar exterior air turbulence and track excitation. The two types of coaches are contiguously marshaled in the adjacent positions of a same train, both of which are motors. A long-term monitoring and analysis of the wheel wear status and the interior vibration-noise of coaches X and Y marshaled in trains are conducted focusing on the relationship between the interior abnormal noise and the non-circular wear of wheels. The test results shows that the type X coach generates higher abnormal vibration and noise than type Y coach. The abnormal vibration and noise are sensitive to the high-order polygonal wear of the coach wheels. It is also found that the higher vibration and noise on type X coach is related to its special interior structural.

Assessment of rural soundscapes with high-speed train noise

In the present study, rural soundscapes with high-speed train noise were assessed through laboratory experiments. A total of ten sites with varying landscape metrics were chosen for audio-visual recording. The acoustical characteristics of the high-speed train noise were analyzed using various noise level indices. Landscape metrics such as the percentage of natural features (NF) and Shannon's diversity index (SHDI) were adopted to evaluate the landscape features of the ten sites. Laboratory experiments were then performed with 20 well-trained listeners to investigate the perception of high-speed train noise in rural areas. The experiments consisted of three parts: 1) visual-only condition, 2) audio-only condition, and 3) combined audio-visual condition. The results showed that subjects' preference for visual images was significantly related to NF, the number of land types, and the A-weighted equivalent sound pressure level (LAeq). In addition, the visual images significantly influenced the noise annoyance, and LAeq and NF were the dominant factors affecting the annoyance from high-speed train noise in the combined audio-visual condition. In addition, Zwicker's loudness (N) was highly correlated with the annoyance from high-speed train noise in both the audio-only and audio-visual conditions.

Psychoacoustic Properties Analysis on Interior Noise of High-Speed Trains

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.

Aerodynamic noise reduction of a gangway in a high-speed train

Excessive interior noise of high-speed trains causes annoyance, fatigue and stress to passengers. Moreover, the noise occurred in gangway is greater than other noise in the room. Therefore, a research for gangway noise reduction was carried out. At first, cavity noise which causes major noise between car-sections was simulated with Fluent 6.0 (computer fluid dynamics program). From the simulation result, the flow feedback loop phenomena in the cavity were observed. Then, noise measurements at internal and external positions in between-cars sections were conducted during the driving of a high-speed train. From the measurement results, noise characteristics of gangway and between-cars section were identified. Finally, noise mitigation methods were suggested in this paper.

Independent vector analysis using subband and subspace nonlinearity

Independent vector analysis (IVA) is a recently proposed technique, an application of which is to solve the frequency domain blind source separation problem. Compared with the traditional complex-valued independent component analysis plus permutation correction approach, the largest advantage of IVA is that the permutation problem is directly addressed by IVA rather than resorting to the use of an ad hoc permutation resolving algorithm after a separation of the sources in multiple frequency bands. In this article, two updates for IVA are presented. First, a novel subband construction method is introduced, IVA will be conducted in subbands from high frequency to low frequency rather than in the full frequency band, the fact that the inter-frequency dependencies in subbands are stronger allows a more efficient approach to the permutation problem. Second, to improve robustness and against noise, the IVA nonlinearity is calculated only in the signal subspace, which is defined by the eigenvector associated with the largest eigenvalue of the signal correlation matrix. Different experiments were carried out on a software suite developed by us, and dramatic performance improvements were observed using the proposed methods. Lastly, as an example of real-world application, IVA with the proposed updates was used to separate vibration components from high-speed train noise data.