Influence of Operational Parameters on Tyre Noise in Semi-Anechoic Chamber 2023-01-1067

There are two key factors driving tyre manufacturers to increase their focus on improving the noise characteristics of the tyre: Strict homologation requirements for tyre and vehicle noise and the increasing prevalence of Electric vehicles. This paper represents the experimental analysis for understanding the effect of various operational parameters such as load, Inflation pressure and speed on overall tyre noise in a semi-anechoic chamber under controlled conditions. To understand the impact of the operational parameters, five tyres with different rim sizes (14" - 18") with the same tread patterns were used. The study includes measuring the overall tyre noise using microphones at three different locations inside the semi-anechoic chamber on a 2m steel drum i.e., leading edge, trailing edge, and centre. These three microphone locations will help us to recognize the impact of the operational parameters on aerodynamic, vibrational and amplification or reduction noise-generating mechanisms. A test matrix with varying load (50%-125%), speed (40kph-100kph) and inflation pressure (200kPa to 260kPa) was used to capture the overall characteristics. It is found that the tyre speed has a greater influence on the tyre/road interaction noise than load and inflation pressure. At constant load, the effect of Inflation pressure with varying speed is very minimal with only 0.1dBA - 0.3dBA difference at all the measurement points. The influence of load on overall tyre noise is very linear as the speed increases. At constant speed, the overall noise at centre microphone was high due to the direct relation of load to sidewall deflection. Smaller-size tyres (14'' & 15") at low speeds (40kph & 60kph) exhibit higher noise levels than bigger tyres. This study will be further extended to investigate the effect of the ISO asphalt surface in semi-anechoic chamber and the measurement of noise at vehicle level using CPX measurement technique.