Characteristics and Mechanism Analysis of Aerodynamic Noise Sources for High-Speed Train in Tunnel

We aim to study the characteristics and mechanism of the aerodynamic noise sources for a high-speed train in a tunnel at the speeds of 50 m/s, 70 m/s, 83 m/s, and 97 m/s by means of the numerical wind tunnel model and the nonreflective boundary condition. First, the large eddy simulation model was used to simulate the fluctuating flow field around a 1/8 scale model of a high-speed train that consists of three connected vehicles with bogies in the tunnel. Next, the spectral characteristics of the aerodynamic noise source for the high-speed train were obtained by performing a Fourier transform on the fluctuating pressure. Finally, the mechanism of the aerodynamic noise was studied using the sound theory of cavity flow and the flow field structure. The results show that the spectrum pattern of the sound source energy presented broadband and multipeak characteristics for the high-speed train. The dominant distribution frequency range is from 100 Hz to 4 kHz for the high-speed train, accounting for approximately 95.1% of the total sound source energy. The peak frequencies are 400 Hz and 800 Hz. The sound source energy at 400 Hz and 800 Hz is primarily from the bogie cavities. The spectrum pattern of the sound source energy has frequency similarity for the bottom structure of the streamlined part of the head vehicle. The induced mode of the sound source energy is probably the dynamic oscillation mode of the cavity and the resonant oscillation mode of the cavity for the under-car structure at 400 Hz and 800 Hz, respectively. The numerical computation model was checked by the wind tunnel test results.

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Comparative Study on Aerodynamic Noise of Dimensionally Similar Locomotive Models of High Speed Trains

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.226-228.417 ◽

2012 ◽

Vol 226-228 ◽

pp. 417-422

Author(s):

Yi Gang Wang ◽

Yang Yang ◽

Jia Shun Yang ◽

Zhi Gang Yang

Keyword(s):

Wind Tunnel ◽

High Speed ◽

Spectral Characteristics ◽

Wind Tunnel Test ◽

Scale Model ◽

Source Distribution ◽

Aerodynamic Noise ◽

Far Field ◽

The Difference ◽

Field Noise

This study is focused on the locomotive of high speed train. First, wind tunnel test is used to verify the credibility of numerical results. Then, in order to compare the difference of aerodynamic noise generated by different size locomotive, dimensionally similar models of 1/8th, 1/12th and 1/15th scale are studied by using numerical simulation, including stationary aerodynamic characteristics, fluctuation characteristics of unsteady flow, noise source distribution on surface and far-field noise spectral characteristics. Based on the result of pressure fluctuation, it is noted that the difference between 1/15th and 1/8th scale model is larger in individual parts, including the separation zone in the roof and the edge of window. In addition, according to the far-field noise calculation, the result of 1/12th scale model is better than 1/15th scale model. From the results mentioned above, 1/15th or much smaller scale model should not be used in wind tunnel test as possible.

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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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A Numerical Study on Aerodynamic Noise Sources of High-Speed Train

Proceedings of the 1st International Workshop on High-Speed and Intercity Railways - Lecture Notes in Electrical Engineering ◽

10.1007/978-3-642-27963-8_11 ◽

2012 ◽

pp. 107-116 ◽

Cited By ~ 3

Author(s):

Yan Yang ◽

Guowei Yang

Keyword(s):

High Speed ◽

Numerical Study ◽

Aerodynamic Noise ◽

High Speed Train ◽

Noise Sources

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Wind Tunnel Tests on Aerodynamic Noise from the Head Car of a High-speed Train

Lecture Notes in Electrical Engineering - Green Connected Automated Transportation and Safety ◽

10.1007/978-981-16-5429-9_12 ◽

2021 ◽

pp. 163-176

Author(s):

Hai Deng ◽

Yigang Wang ◽

Qiliang Li ◽

Zhe Shen ◽

Yang Gao ◽

...

Keyword(s):

Wind Tunnel ◽

High Speed ◽

Aerodynamic Noise ◽

High Speed Train ◽

Wind Tunnel Tests

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Unsteady Aerodynamic Characteristics of a High Speed Train with Crosswind

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.66-68.1878 ◽

2011 ◽

Vol 66-68 ◽

pp. 1878-1882

Author(s):

Ming Lu Zhang ◽

Yi Ren Yang ◽

Chen Guang Fan ◽

Li Lu

Keyword(s):

Wind Tunnel ◽

Flow Field ◽

High Speed ◽

Stokes Equations ◽

Three Dimensional ◽

Aerodynamic Characteristics ◽

Navier Stokes ◽

Vehicle Speed ◽

High Speed Train ◽

Mesh Method

The aerodynamic performances of a high speed train will significant change under the action of the crosswind. Large eddy simulation (LES) was made to solve the flow around a simplified CRH2 high speed train with 250km/h and 350km/h under the influence of a crosswind with 28.4m/s base on the finite volume method and dynamic layering mesh method and three dimensional incompressible Navier-Stokes equations. Wind tunnel experimental method of static train with relative flowing air and dynamic mesh method of moving train were compared. The results of numerical simulation show that the flow field around train is completely different between Wind tunnel experiment and factual running. Many vortices will be produced on the leeside of the train with alternately vehicle bottom and back under the influence of a crosswind. The flow field around train is similar with different vehicle speed.

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Noise Analysis of a Range Hood

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.318.243 ◽

2013 ◽

Vol 318 ◽

pp. 243-247

Author(s):

Wei Zhang ◽

Rong Hua Su ◽

Yang Gao ◽

Hong Shuang Shen

Keyword(s):

Numerical Simulation ◽

Flow Field ◽

Noise Analysis ◽

Spectral Characteristics ◽

Sound Field ◽

Simulation Method ◽

National Standards ◽

Aerodynamic Noise ◽

Noise Sources ◽

Radiated Noise

In order to find the vibration and noise sources of a certain type of range hood and analyze the aerodynamic noise's generating mechanism of it, vibration and radiated noise produced by a working range hood were measured with vibration accelerometers, microphones and other precision instruments under the condition of semi-free sound field, according to the national standards. Spectrum analysis methods were adopted to analyze the spectral characteristics of the noises, and the frequency distribution was obtained. A model of the range hood fan was built, and the inner flow field distribution of the fan was analyzed with numerical simulation method. The vibration and noise sources of the range hood were finally found and the presence of the aerodynamic noise was proved. Some suggestions on the improvement of the range hood fan were also given.

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Analysis of Aerodynamic Noise Characteristics of High-Speed Train Pantograph with Different Installation Bases

Applied Sciences ◽

10.3390/app9112332 ◽

2019 ◽

Vol 9 (11) ◽

pp. 2332 ◽

Cited By ~ 3

Author(s):

Yongfang Yao ◽

Zhenxu Sun ◽

Guowei Yang ◽

Wen Liu ◽

Prasert Prapamonthon

Keyword(s):

High Speed ◽

Near Field ◽

Complex Structure ◽

Aerodynamic Noise ◽

High Speed Train ◽

Noise Sources ◽

Eddy Simulation ◽

Noise Characteristics ◽

Large Eddy ◽

Flow Phenomena

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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