Synthesis of equivalent sources for tyre/road noise simulation and analysis of the vehicle influence on sound propagation

Road traffic noise affects the well-being of people living in urban areas. Amongst the noise sources, tyre/road interaction plays a major role. In this context, predictive acoustic models can be useful for the tyre industry to design quiter tyres. This paper deals with a methodology for simulating tyre/road noise through equivalent monopoles, synthesised using an inverse problem approach, starting from indoor tests performed in a semi-anechoic chamber. A drum with an ISO 10844 road replica is used to obtain realistic tread pattern and road roughness excitations. The experimental setup and a dedicated signal processing technique are described here. To perform the source synthesis, data is combined with acoustic finite element models based on a deformed treaded tyre geometry, in order to take the acoustic resonances at the tyre/road interface into account. The synthesised monopoles are then used to run a numerical simulation including a vehicle in order to consider its influence on sound propagation. The results are then validated by comparing them with indoor measurements.