Abstract
Research in tyre noise is becoming increasingly important. In the future, car manufacturers will have to meet stringent conditions that enforce extremely low noise levels. Engine, intake and exhaust noise sources have been considerably reduced in the past and, therefore, the relative contribution of tyre noise to the total radiated sound is increasing. Furthermore, car users demand that new cars should be more comfortable and, thus, require lower interior and vibration levels. Tyre road noise is generated by vibrational effects mainly caused by the impact of tread blocks on the road surface and aerodynamic effects, due to resonances of the air being pumped into the grooves inside the contact area.
This paper explores a method to characterise the acoustic radiation of a tyre due to wall vibration in terms of the relative amplitude of fundamental acoustic sources that, acting simultaneously, reproduce the same acoustic field than that caused by the vibrating tyre. This approach can be used to reveal the fundamental structure of the acoustic field produced by a vibrating tyre and, thus, is of practical interest to define the fundamental mechanisms that control tyre wall and tread acoustic radiation.