Investigation of Tire Road Noise with Special Consideration of Airborne Noise Transmission

One of the main customer requirements for passenger cars is a pleasant sound based on a low interior noise level. Because of the reduction of many single noise sources, tyre road noise is now becoming increasingly important.

In this paper an efficient approach for investigation of tire road noise is presented. First based on coherence analysis the main noise transmission behaviors are identified. Relevant frequency ranges for structure borne noise and airborne noise can be determined. Additionally it’s possible to separate noise transmission coming from front or rear axle. With this preliminary analysis /1/ it’s possible to reduce the effort to the limit.

Now for structure borne noise transmission as well as for airborne noise transmission the critical paths are identified via transfer path analysis (TPA). For the estimation of airborne noise paths two different methods are compared. First the relevant airborne noise transfer paths are estimated via matrix inversion method /2/. Second a simplified method /3/ is applied. Based on a case study for a passenger car of the luxury class, both methods are described in detail. First physical modifications verify the results of the transmission study.

At last some advantages and disadvantages are discussed and a perspective in further applications is given.