Research on the resonance frequency splitting mechanism and novel modal characteristics of a rotating tire acoustic cavity

Tire acoustic cavity resonance (TACR) noise contributes significantly to interior noise for lower powertrain noise passenger cars and electric cars, which affects the ride comfort obviously. To design sound absorption structures effectively, it is crucial to clarify the evolution mechanism and influence factors of the resonance frequencies and acoustic modal shapes with the running speed. Aiming at these problems, in this paper, a theoretical model of sound wave propagation in a tire acoustic cavity is constructed based on the superposition principle of traveling waves, and the sound field distributions under different rotating speeds are investigated. The formation conditions of TACR are summarized from the perspective of wavenumber. Especially for a rotating tire acoustic cavity, some novel modal characteristics, such as the novel deflective modal shapes and the continuously changing phase, are found. And the theoretical calculation results are verified by the experiment and simulation. The significance of this work is that the evolution mechanisms of TACR frequency and modal shape with the tire rotating speed are theoretically clarified and revealed, which are helpful to obtain effective solutions to suppress TACR noise.