Cavity Noise of Passenger Car Tires - Influencing Factors and Optimization Measures
chassis.tech plus 2010
The tire cavity acoustic mode leads to audible noise inside the vehicle interior. Due to the continuous reduction of the overall driving noise, tire cavity noise has become more important for car manufacturers.
To investigate different influencing factors, measurements on a driving car were per-formed. Several parameters were varied and the influence on the cavity noise was analyzed. The influencing factors known from literature could be confirmed: e.g. the Doppler-effect could be identified (frequency split) as well as the frequency shift due to temperature change.
Furthermore, new questions were brought up, e.g. the influence of pressure is still an open question: A frequency shift was observed only for the low frequency peak whereas the high frequency peak remains at the same frequency.
In addition, different proposals to reduce the cavity mode amplitude are analyzed and evaluated. Despite the different physical mechanisms all the optimization measures show good effectivity. The sound pressure level (SPL) reduction at low driving speeds in the vehicle interior is up to 8 dB(A) in the frequency range of the cavity mode.