Predicting the wind noise from the pantograph cover of a train

Holmes, Bayard S.; Dias, João B.; Jaroux, Belgacem; Sassa, Takamitsu; Ban, Yasuhiro

doi:10.1002/(sici)1097-0363(199706)24:12<1307::aid-fld561>3.0.co;2-8

Cited by 29 publications

(12 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Holmes et al [19] combined boundary element method (BEM) and finite element method (FEM) to calculate aerodynamic noise by a 1:10 scale model of pantograph cover at the speed of 250 km/h. Kitagawa and Nagakura [20] developed a method to calculate high-speed train noise and further analyzed the measured noise data on Shinkansen trains at 120 km/h or higher speed.…”

Section: Introductionmentioning

confidence: 99%

On aerodynamic noises radiated by the pantograph system of high-speed trains

Zhang

2013

Acta Mech Sin

View full text Add to dashboard Cite

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 WilliamsHawkings (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.

show abstract

Section: Introductionmentioning

confidence: 99%

On aerodynamic noises radiated by the pantograph system of high-speed trains

Zhang

2013

Acta Mech Sin

View full text Add to dashboard Cite

show abstract

“…Research studies have been performed to determine the acoustic signatures of a shroud design (see, e.g., Holmes et al, 1997). In Holmes et al (1997) a Large Eddy Simulation is performed to determine the turbulent fluid flow in the vicinity of a shroud. See Figure 3 for a schematic illustration.…”

Section: Introductionmentioning

confidence: 99%

Multiscale and Stabilized Methods

Hughes¹,

Scovazzi²,

Franca³

2004

Encyclopedia of Computational Mechanics

128

179

View full text Add to dashboard Cite

This article presents an introduction to multiscale and stabilized methods, which represent unified approaches to modeling and numerical solution of fluid dynamic phenomena. Finite element applications are emphasized but the ideas are general and apply to other numerical methods as well. (They have been used in the development of finite difference, finite volume, and spectral methods, in addition to finite element methods.) The analytical ideas are first illustrated for time‐harmonic wave‐propagation problems in unbounded fluid domains governed by the Helmholtz equation. This leads to the well‐known Dirichlet‐to‐Neumann formulation. A general treatment of the variational multiscale method in the context of an abstract Dirichlet problem is then presented, which is applicable to advective–diffusive processes and other processes of physical interest. It is shown how the exact theory represents a paradigm for subgrid‐scale models and a posteriori error estimation. Hierarchical p ‐methods and bubble function methods are examined in order to understand and ultimately approximate the ‘fine‐scale Green's function’ that appears in the theory. Relationships among so‐called residual‐free bubbles, element Green's functions, and stabilized methods are exhibited. These ideas are then generalized to a class of nonsymmetric, linear evolution operators formulated in space–time. The variational multiscale method also provides guidelines and inspiration for the development of stabilized methods (e.g. SUPG, GLS, etc.) that have attracted considerable interest and have been extensively utilized in engineering and the physical sciences. An overview of stabilized methods for advective–diffusive equations is presented. A variational multiscale treatment of incompressible viscous flows, including turbulence is also described. This represents an alternative formulation of Large Eddy Simulation, which provides a simplified theoretical framework of LES with potential for improved modeling.

show abstract

“…In contrast to the 6th power law relationship found in MAGLEV as a whole, the operators of the more conventional high speed trains have attempted to derive their own proportionality relationships between the aerodynamic noise and train speed for different parts of the train [5][6][7]. Table 1 summarizes the power law relationships for these trains.…”

Section: Power Law Relationshipsmentioning

confidence: 99%

Analysis of Aerodynamic Noise at Inter-coach Space of High Speed Trains

Kim¹,

Kim²

2014

International Journal of Railway

View full text Add to dashboard Cite

A numerical analysis method for predicting aerodynamic noise at inter-coach space of high-speed trains, validated by wind-tunnel experiments for limited speed range, is proposed. The wind-tunnel testing measurements of the train aerodynamic sound pressure level for the new generation Korean high-speed train have suggested that the inter-coach space aerodynamic noise varies approximately to the 7.7th power of the train speed. The observed high sensitivity serves as a motivation for the present investigation on elucidating the characteristics of noise emission at inter-coach space. As train speed increases, the effect of turbulent flows and vortex shedding is amplified, with concomitant increase in the aerodynamic noise. The turbulent flow field analysis demonstrates that vortex formation indeed causes generation of aerodynamic sound. For validation, numerical simulation and wind tunnel measurements are performed under identical conditions. The results show close correlation between the numerically derived and measured values, and with some adjustment, the results are found to be in good agreement. Thus validated, the numerical analysis procedure is applied to predict the aerodynamic noise level at inter-coach space. As the train gains speed, numerical simulation predicts increase in the overall aerodynamic sound emission level accompanied by an upward shift in the main frequency components of the sound. A contour mapping of the aerodynamic sound for the region enclosing the inter-coach space is presented.

show abstract

Predicting the wind noise from the pantograph cover of a train

Cited by 29 publications

References 17 publications

On aerodynamic noises radiated by the pantograph system of high-speed trains

On aerodynamic noises radiated by the pantograph system of high-speed trains

Multiscale and Stabilized Methods

Analysis of Aerodynamic Noise at Inter-coach Space of High Speed Trains

Contact Info

Product

Resources

About