Tyre cavity noise: porous materials as a countermeasure

The first resonance of the tyre air cavity can significantly affect vehicle interior noise at frequencies around 200 Hz. The insertion of a sound absorbing liner inside a tyre is known to be an efficient countermeasure to this problem and tyre manufacturers are already producing tyres implementing this solution. The present work proposes a methodology for predicting the damping performance of a lined tyre by means of numerical models. The geometry of the tyre cavity and the lining, as well as the properties of the sound absorbing material are taken into account and predictions are made concerning the effect of specific combinations of volume and properties of the liner. For fixed material characteristics, the volume of the lining treatment strongly influences the attenuation of the cavity resonance. Moreover, the simulations performed suggest that for fixed volume and material properties, larger attenuation of the cavity resonance peak can be obtained by adopting a discontinuous layout.