Experimental analysis of wheel/rail noise by near field acoustical imaging

Abstract In this paper a near field acoustical imaging method applied to the localization and analysis of rolling noise sources on a wheel of a railway tracked vehicle is presented. This method consists in using an acoustical plane microphone array (mounted on the vehicle), which may be moved depending on the wheel/rail part being investigated. A space-frequency processing of the acoustical signals given by the array then enables one—among other things—to evaluate the acoustical energy radiated by the area considered, in a given octave band.