Development of the urban rail vehicle acoustic model

Abstract

Noise emitted by urban rail transport is one of the four main sources of noise in urban agglomerations (according to the Environmental Noise Directive 2002/49/EC), and therefore it is subject to cyclical quantification and control. For this purpose, various types of acoustic maps are made, however, as scientific research shows, not every acoustic model is best suited for conducting effective quantitative analyses. Another problem is to carry out effective qualitative analyses, which additionally represent structural distribution of rolling noise generated by rail vehicles. The authors of the article present an original model of acoustic signature emitted by a selected type of urban rail vehicle in normal operation. To carry out the investigation, several dozen sound measurements were made according to own research methodology as well as several acoustic roughness measurements of wheel and rail rolling surfaces. The most important conclusion of this paper is the fact that based on validation and verification it can be concluded that the developed model is very well suited to estimate octave spectra of sound levels in relation to distance from the source (range 1–10 m) and speed (range 40–70 km/h) of a passing city rail vehicle.