Localization of aerodynamic noise sources of Shinkansen trains
TL;DR: In this article, wind tunnel tests using a 1/5 scale Shinkansen train model were performed and an acoustic mirror, which consists of an omni-directional microphone and a reflector, was chosen as a measuring device.
About: This article is published in Journal of Sound and Vibration.The article was published on 2006-06-13. It has received 70 citations till now. The article focuses on the topics: Noise & Noise reduction.
Citations
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05 Jun 2015
TL;DR: In this article, the main source of noise from trains is the aerodynamic noise caused by the air flow over the train structure, and the sound level increases with train speed at a rate of between 60 and 80 times the logarithm of the speed.
Abstract: At speeds above 300–350 km/h, the main source of noise from trains is the aerodynamic noise caused by the air flow over the train structure. The sound level increases with train speed at a rate of between 60 and 80 times the logarithm of the speed so that, as speeds increase further, the noise increases dramatically. The main aerodynamic noise is produced by the air flow passing over the pantograph, the train nose, the bogie region and cavities such as the pantograph recess and the inter-coach gap. Experimental and numerical methods for studying aerodynamic noise are reviewed including the use of microphone arrays, wind tunnels, computational fluid dynamics and semi-empirical methods. Potential mitigation measures that can control aerodynamic noise are also reviewed.
94 citations
Cites methods from "Localization of aerodynamic noise s..."
...Nagakura [27] suggested a method for estimating quantitatively the noise radiated from each part of the train using such an acoustic International Journal of Rail Transportation 123...
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01 Sep 2012
TL;DR: The second edition of a guidance manual originally issued in 2005, which presents procedures for predicting and assessing noise and vibration impacts of high-speed ground transportation projects, is presented in this paper, where the authors discuss mitigation measures for dealing with adverse noise impacts.
Abstract: This report is the second edition of a guidance manual originally issued in 2005, which presents procedures for predicting and assessing noise and vibration impacts of high-speed ground transportation projects. Projects involving high-speed trains using traditional steel-wheel on steel-rail technology as well as magnetically levitated (maglev) systems are included. Procedures for assessing noise and vibration impacts are provided for different stages of project development, from early planning through preliminary engineering and final design. For both noise and vibration, three levels of analysis are described including a preliminary impact screening, a general assessment and a detailed analysis. This updated guidance contains models for predicting high-speed train noise and vibration as well as criteria for assessing the magnitude of potential impacts. A range of mitigation measures are described for dealing with adverse noise and vibration impacts. There is a discussion of noise and vibration during the construction stage and also a discussion of how the technical information should be presented in the Federal Railroad Administration’s environmental documents. This guidance will be of interest not only to technical specialists who conduct the analyses but also to project sponsors, Federal agency reviewers, and members of the general public who may be affected by the projects.
83 citations
TL;DR: The definition, properties, and reason that why L-kurtosis is robust to the outliers are analyzed and it is proposed that L-Kurtosis value 0.1226 may replace k Kurtosis value 3 as a threshold in fault diagnosis.
46 citations
TL;DR: In this article, a hybrid method of nonlinear acoustic solver (NLAS) and Fowcs Williams-Hawkings (FW-H) acoustic analogy is used to predict the aerodynamic noise of pantograph system in this speed range.
Abstract: Pantograph system of high-speed trains become significant source of aerodynamic noise when travelling speed exceeds 300 km/h. In this paper, a hybrid method of non-linear acoustic solver (NLAS) and Ffowcs Williams-Hawkings (FW-H) acoustic analogy is used to predict the aerodynamic noise of pantograph system in this speed range. When the simulation method is validated by a benchmark problem of flows around a cylinder of finite span, we calculate the near flow field and far acoustic field surrounding the pantograph system. And then, the frequency spectra and acoustic attenuation with distance are analyzed, showing that the pantograph system noise is a typical broadband one with most acoustic power restricted in the medium-high frequency range from 200 Hz to 5 kHz. The aerodynamic noise of pantograph systems radiates outwards in the form of spherical waves in the far field. Analysis of the overall sound pressure level (OASPL) at different speeds exhibits that the acoustic power grows approximately as the 4th power of train speed. The comparison of noise reduction effects for four types of pantograph covers demonstrates that only case 1 can lessen the total noise by about 3 dB as baffles on both sides can shield sound wave in the spanwise direction. The covers produce additional aerodynamic noise themselves in the other three cases and lead to the rise of OASPLs.
40 citations
TL;DR: A novel hybrid method of L-kurtosis and enhanced clustering-based segmentation is proposed that enables the efficient recognition of faults in axial piston pumps.
32 citations
References
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02 Jun 1998
TL;DR: In this article, an acoustic mirror was employed on a 1/10 scale-model wing section to identify the aeroacoustic source mechanisms of slat-noise and flap side-edge noise.
Abstract: Employment of very quiet high-bypass-ratio engines to propel current and future "very large aircraft" has caused airframe noise to become a significant contributor to the overall radiated noise from an aircraft in landing approach. This has brought about a worldwide resurgence of airframe noise studies, to try and understand the aeroacoustics of, and to ultimately control the aerodynamically caused noise from aircraft components deployed during the final approach leg, such as landing gears and high-lift devices (HLD) on wings. In view of European aviation industry to design and build a very large commercial aeroplane, a substantial and dedicated German National Research Project was initiated, culminating in a series of model- und full-scale wind tunnel experiments on HLD. This paper discusses initial results from HLD-studies in the DLR Aeroacoustics Wind Tunnel Brauschweig (AWB) where an acoustic mirror was employed on a 1/10 scale-model wing section to identify the aeroacoustic source mechanisms of slat-noise and flap side-edge noise. Tests were performed for different flow velocities and wing angles-of-attack, indicating that the very slat tracks constitute sources of excessive flow noise. Moreover, both slat-noise and flap side-edge noise, respectively, were found to each be a result of specific combinations of different unsteady-aerodynamics mechanisms. Several, though still preliminary noise reduction techniques were tested, showing nevertheless significant promise to enable containment of otherwise excessive slat-noise and flap side-edge noise, such techniques being quite feasible for future full-scale application.
146 citations
TL;DR: In this article, a method of analyzing Shinkansen noise at speeds between 120 and 315 km/h was developed and applied to the measured data of SHINSEWAY noise.
55 citations
TL;DR: In this paper, a review of Shinkansen noise and methods for its control is given, and the methods of treatment of the data obtained by this measuring equipment are shown and the amount of noise generated from the individual noise source is estimated.
39 citations
TL;DR: The Large-scale Low-noise Wind Tunnel (LWN) at Maibara, Japan as discussed by the authors was used to study aerodynamic noise and other aerodynamic phenomena related to the operation of high-speed trains and to test systems to reduce deleterious effects.
Abstract: This article describes the specifications of the Large-scale Low-noise Wind Tunnel completed at Maibara, Japan in 1996. It is used to study aerodynamic noise and other aerodynamic phenomena related to the operation of high-speed trains and to test systems to reduce deleterious effects. Two features stand out: extremely low background noise and a device that enables simulation of the movement of airflow between a testing subject and the ground. Future tasks include making wind tunnel measurements more accurate and conducting field tests to establish comparisons to actual operations.
30 citations
06 May 1996
19 citations