Experimental Observations in Tire Cavity Resonance and Interactions with Periodic Noise Components

Tire cavity resonance is one of the major sources of tire-related in-cabin noise and vibration. It has gained more attention in recent years with the growth of the electric vehicle market. This is due to the absence of masking noise from the internal combustion engine and powertrain. Thus, the mitigation of this issue has become a critical task for tire and vehicle manufacturers. The excited cavity resonant frequency in an unloaded condition is typically between 170 - 220 Hz. However, multiple studies have shown that loading the tire will result in two dominant resonances transmitted into the cavity. Their corresponding mode shapes are typically described in terms of the direction of their characteristic acoustic pressure variation i.e., fore-aft cavity mode and vertical cavity mode. As the tire's rotational speed increases, in-cabin measurements show that the tire cavity resonant frequencies separate from each other. Further, interactions with the periodic component of tire noise at certain speeds are also observed. These periodic components can be attributed to tire non-uniformities and tread pattern related excitation. This interaction is perceived as tonal noise inside the vehicle cabin at discrete speeds. This work presents experimental results summarizing these findings.