Analysis of coast-by noise of heavy truck tires

Heavy truck tires are one of the main sources of road traffic noise. However, the mechanism and propagation of the noise generated by these tires have not been systematically investigated. To determine the noise of heavy truck tires with different structures and patterns, and to analyze the correlation between the indoor tire noise and coast-by tire noise, an integrated tire indoor noise test and a coast-by noise test were designed and successfully implemented. The indoor test was conducted on a drum inside a semi-anechoic chamber to simultaneously measure the near field and far field noise of the tires. The outdoor measurements were carried out using a coast-by test on the new ISO 10844 surface. A formula for quantitative analysis with appropriate corrections was developed to analyze the data with reasonable errors, which can be used to predict the coast-by noise through the indoor tire noise test accurately and effectively. The analysis shows that when trying to build the relationship between indoor and outdoor heavy truck tire noise, care should be taken to differentiate the tires with a load capacity index in excess of 121 and without any dual fitting indication from ordinary tires, due to the specified test procedure.