Towards auralization of pass-by noise from railway wheels: Sensitivity to the lateral contact position

Paper in proceeding, 2023

Railway rolling noise is typically described in equivalent pass-by noise levels. However, this descriptor does not always sufficiently correlate with the perceived annoyance of, for example, tonal components or transient effects. An auralisation of such effects allows researching this correlation. The wheels are a main contributor to the overall noise level above about 1 kHz. The low damping of the wheels leads to a strong modal behavior. Typically, modes with a strong axial response to a vertical excitation in the wheel-rail contact dominate the radiated sound. The lateral position of this contact point on the wheel tread, and thus the modal excitation, is therefore an important parameter in an auralisation. However, the exact contact location varies due to the lateral oscillation of the wheelset during running. This paper presents a computationally efficient, time-domain prediction model for the sound pressure produced by one wheel as it passes a stationary track-side position. The model makes use of pre-calculated acoustic transfer functions of each mode, which allow an evaluation of the modal contributions to the track-side sound pressure. The sensitivity of these modal contributions on the lateral contact position is analyzed.