Sound radiation of a rolling tyre
Paper in proceedings, 2011
In this work an advanced tyre model based on Wave Guide Finite Elements is used in connection with a contact model and a radiation model in order to investigate the sound radiation from a rolling tyre. With these tools a slick tyre rolling on an ISO and a rough surface is simulated. Based on the calculated contact forces in the time domain the amplitudes of the modes excited during rolling are determined as function of frequency. A boundary element model is then applied to predict the sound pressure level on a reference surface around a tyre placed on rigid ground as function of the modal composition of the tyre vibrations. Taking into account different modes when calculating the vibrational field as input into the boundary element calculations, it is possible to identify individual modes or groups of modes of special relevance for the radiated sound power. The results show that mainly low-order modes with relative low amplitudes but high radiation efficiency in the frequency range between 800 and 1200 Hz are responsible for the radiated sound power at these frequencies, while those modes which are most strongly excited in that frequency range during rolling are irrelevant for the radiated sound power. This fact is very essential when focusing on the design of quieter tyres.