Tyre noise generation

Abstract Tyre noise is a very important subject because, at least at the higher speeds (more than 60 km h −1 ), it determines the traffic noise which in turn at present is the most annoying noise source. Tyre noise is also a not very well understood noise source because tyres have complicated vibration and radiation properties and because the primary noise generation is due to several mechanisms which depend on subtle details of the radial and tangential motion of tread blocks in and near the contact patch when they are moving on the road surface. In the first part of this paper the vibration patterns and radiation properties of tyres in the acoustic frequency range are briefly described. In the second part some noise generation mechanisms, and some open questions in this field, are discussed.