Contribution
Railway Rolling Noise Synthesis Using a Numerical Modelling Approach
* Presenting author
Abstract:
In this contribution, railway rolling noise is synthesised using a numerical model that combines the existing TWINS (Track Wheel Interaction Noise Software) approach with recently developed models of a rotating railway wheel and a supported track. These models are used to calculate vibroacoustic transfer functions for unit force excitation. From the wheel/track interaction, contact forces are derived in the frequency domain for a unit roughness excitation, and combined with different wheel/rail roughness levels. A random phase is introduced in the roughness to account for its spatial variability and an inverse Fourier transform is applied to convert to the time domain. For sound synthesis, the wheel is modelled as a moving compact source, with a volume velocity that is based on its sound power, and its pass-by signal is generated using a moving Green’s function. The track is modelled as an extended stationary sound source excited by a force moving along the rail. The track pass-by signal is generated by convolving the sampled track impulse responses with the contact force. This modelling approach enables rolling noise auralisation for situations with different train speeds or track conditions that could also be compared with measurements.