Fast and Reliable Noise Predictions for Rolling Stock by Means of Pre-calculated Reference Models

The prediction of the passby noise of trains, in the definition of ISO 3095, can be simplified by looking at how each source contributes to the global level. With some hypotheses, it is possible to write in a very simple way how the passby level of any train configuration depends on the passby level of each source type. This article describes an analytical method to extend known passby noise levels to any train configuration. Its application to numerical simulations is described in depth and compared to existing simulation and experimental results; application to specific measurement setups is only described. Even assuming the access to high computational resources, when using advanced, complex modelling and tools for noise predictions the bottleneck is often the availability of the user/acoustician. This paper presents a framework to pre-calculate passby noise levels with advanced modelling for specific trains, to later extrapolate them exactly to any other configuration of vehicles and sources.