Study on noise dissipation effects of porous materials in suppressing tire acoustic cavity resonance noise

The tire acoustic cavity resonance (TACR) noise is a significant source of the structure-borne noise inside a vehicle in the low-frequency range. This paper studies the noise dissipation effect of porous materials in reducing the TACR noise, an attempt to clarify the acoustic reduction mechanism and improve the accompanying vehicle interior noise level. A numerical model of a simplified tire cavity with rigid boundaries and acoustic excitation is established and further validated by the experiment. The effects of porous parameters on TACR frequency and sound pressure are then investigated and compared. The result reveals that the most influential material parameters are the porosity and material volume. It is also shown that the effectiveness of porous material in the mitigation of noise originates from the curliness of the material, which results in much larger acoustic impedance near the excitation position. Therefore, the sound absorption performance of the cavity attached with porous material proves to be excellent compared to that of the porous material itself. For further studying the damping effects of structural coupling, the flexible boundary of the tire tread is introduced. The results show that the porosity, material volume and structural loss factor of the tread all play important roles in reducing TACR noise.