MEASUREMENT AND ANALYSIS OF TRAIN NOISE DETECTED ON A BUILDING FAÇADE.

Noise produced by the transit of a train is affected by many variables: wheel-rail contact, engine, aerodynamic noise, random events, etc.. Some of these components, such as wheel-rail contact and aerodynamic noise are strongly dependent on high velocity, while other components, such as noise due to engines and auxiliary devices, are relevant in a low velocity regime, especially in proximity of a railway station, in the approaching and leaving phases. In this paper we describe both an experimental activity regarding the measurements of noise produced by low velocity trains and detected on a building façade, close to a railway station at night time, and a semi-quantitative theoretical model which gives the principal shapes of freight trains in various dynamical situations. At this stage of the study, we focus on different types of trains and of running conditions, evaluating their influence on the time history by means of comparisons between software predictions and experimental measurements. The experimental method chosen rely upon the simultaneous detection of the acoustic signals detected by two receivers placed some 30 meters apart and linked to the channels of a class 1 Measuring System.