In recent work it has been possible to model the surface vibration of a loaded rolling tire, including the influence of the acoustic mode that forms within the tire cavity. For example, it has been found that the acoustic cavity mode splits owing to the deformation of the tire when it is loaded, and that the split widens owing to Doppler effects when the tire is rolling. It has also been demonstrated that the force at the hub that results from the acoustic cavity mode is strongly dependent on interaction with circumferential structural modes of the treadband. The finite element models developed to-date, thus allow a prediction of the tire’s surface vibration. To predict the sound radiation from the deformed, rolling tire, the surface vibration data has been used as the input to boundary element calculations; the effect of the ground surface is modeled by creating an “image” tire. The calculations have been used to illustrate the nature of the exterior sound radiation that results from the acoustic cavity mode, which can be relatively efficient due to the sonic phase speed of the mode within the tire cavity, as opposed to the subsonic structural wave propagation along the treadband.
Tire noise, Sound radiation, Boundary elements, Finite elements, Loaded tire, Roiling tire
Acoustics and Noise Control
Date of this Version