Sound Radiation from Railway Wheels including Ground Reflections: A half-space formulation for the Fourier Boundary Element Method
Journal article, 2021

Current models for the acoustic radiation from railway wheels assume free field radiation. However, slab tracks are increasingly used for new railway lines. The acoustically hard surface of those tracks makes a re-evaluation of the free field assumption relevant, as such a surface can affect the radiation efficiency of an acoustic radiator. The wheel as the acoustic radiator is most conveniently described in a cylindrical coordinate system, thus making use of its axisymmetry. While this is a viable solution for the structural vibrations, for instance by using the curved Waveguide Finite Element formulation, the axisymmetry breaks when including a reflective plane in the calculation of the acoustic radiation. A convenient method to include an infinitely large, reflective plane is by using half-space Green’s functions in combination with the Boundary Element method. This method can be formulated in cylindrical coordinates using the Fourier series BEM (FBEM). However, the FBEM has not yet been combined with half-space Green’s functions. This paper provides a half-space formulation for the FBEM, which enables e.g. the evaluation of sound radiation of railway wheels over reflective surfaces. Finally, it is shown that the assumption of free field radiation for railway wheels is valid, as there is no major contribution of the reflective plane to the radiation efficiency of the wheel. The developed method is validated against laboratory measurements as well as analytical models.

Radiation Efficiency


Green's Functions

Slab Track

Waveguide FEM

Railway Wheel


François Fabre

Jannik Theyssen

Chalmers, Architecture and Civil Engineering, Applied Acoustics

Astrid Pieringer

Chalmers, Architecture and Civil Engineering, Applied Acoustics

Wolfgang Kropp

Chalmers, Architecture and Civil Engineering, Applied Acoustics

Journal of Sound and Vibration

0022-460X (ISSN) 1095-8568 (eISSN)

Vol. 493 115822

Buller från ballastfria spår

Swedish Transport Administration, 2017-01-01 -- 2018-12-31.

Driving Forces

Sustainable development

Areas of Advance


Subject Categories

Applied Mechanics

Fluid Mechanics and Acoustics



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